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MJLT1-SALINE SAMPLE DISTILLATION APPARATUS
FOR HYDROGEN ISOTOP E ANALYSES
DESIGN AN D ACCURACY
US GEOLOGICAL SURVEY Water-Resources Investigations 81-25
ki7S C-PliefP Orir 0 51981 11-
50272 -101 3 Recipients Accession No1 REPORT NOREPORT DOCUMENTATION
PAGE USGSWRDWRI81-25 4 Title and Subtitle 5 Report Date
April 1981MULTI-SALINE SAMPLE DISTILLATION APPARATUS FOR HYDROGEN ISOTOPE ANALYSES DESIGN AND ACCURACY
6
7 Author(s) 8 Performing Organization Rept No
Afifa A Hassan 9 Performing Organization Name and Address 10 ProjectTaskWork Unit No
U S Geological Survey Water Resources Division 11 Contract(C) or Grant(G) No
12201 Sunrise Valley Drive Mail Stop 432 Reston Virginia 22092 (C)
(G)
12 Sponsoring Organization Name and Address 13 Type of Report amp Period Covered
U S Geological Survey Water Resources Division 12201 Sunrise Valley Drive Mail Stop 432
14 Reston Virginia 22092
15 Supplementary Notes
16 Abstract (Limit 200 words)
A distillation apparatus for saline water samples was designed and tested Six samples may be distilled simultaneously The temperature was maintained at 400degC to ensure complete dehydration of the precipitating salts Consequently the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated
17 Document Analysis a Descriptors
Desalination Apparatus Stable Isotopes Hydrogen
b IdentifiersOpen-Ended Terms
c COSATI FieldGroup
18 Availability Statement
No restriction on distribution Prepared for NTIS by U S Geological Survey WRD
19 Security Class (This Report)
Unclassified_ 20 Security Class (This Page)
Unclassified
21 No of Pages
4 22 Price
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35) Department of Commerce
(See ANSImdashZ3918) See Instructions on Reverse
IVIbdquoLTI-SALIE SA VPLE DISTILLATIO APPARATUS FOR HYDROGE ISOTO 1 ANALYSES
DESIG AD ACCJRACY
By AF1FA AFIFI HASSAN
US GEOLOGICAL SURVEY
Water-Resources Investigations 81-25
1981
UITED STATES DEPARTMENT OF TH INTERIOR JAMES G WA I I Secretary
GEOLOGICAL SURVEY
Doyle G Frederick Acting Director
For additional information write to
Chief Hydrologist US Geological Survey WRD 432 National Center Reston Virginia 22092
CONTENTS
Page
Abstract 1
Introduction
Method and Results 34
1
Apparatus 3
Conclusions 4
References 4
ILLUSTRATIONS
Page
Figure 1 Sketch showing multi-saline sample dis-tillation apparatus for hydrogen isotope analyses
iii
2
MULTI-SALINE SAMPLE DISTILLATION APPARATUS FOR HYDROGEN ISOTOPE ANALYSES
DESIGN AND ACCURACY
By Afifa Afifi Hassan
ABSTRACT
A distillation apparatus for saline water samples was designed and tested Six samples may be distilled simultaneously The temperature was maintained at 400degC to ensure complete dehydration of the precipita-ting salts Consequently the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated
INTRODUCTION
The most commonly used method to convert water to hydrogen for stable isotope analyses is the reaction with hot uranium (Bigeleisen and others 1952) However water samples containing more than 1000 ppm salts require distillation before they are injected into the sample preparation vacuum line to minimize memory effects resulting from precipitation of dehydrated salts Distillation vials containing glass beads (fig 1) are used to distill water samples one at a time without a heat controller (Truesdell personal oral communication to Tyler Coplen 1978) The temperature is unknown
The problem of concern is that upon evaporation during distillation hydrated salts that precipitate may not be completely dehydrated For example MgC12 6H20 (Bischofite) KC1MgC12 6H20 (Carnallite) MgSO4 7H20 (Epsomite) and MgSO4 H2O (Kieserite) may precipitate To determine the hydrogen isotopic compostion of the water accurately all the water and OH groups must be driven out of these salts Most of the water-containing salts except Bischofite completely dehydrate at 200degC or less Bischo-fite dehydrates in two steps The first step may form Brucite Mg(OH)2 which in turn dehydrates at 350degC Another problem of concern is the loss of HC1 formed during dehydration of the magnesium chloride salts An example of the reaction is as follows
MgCl2 6H2C----40- 2 HC1 + Mg(OH)2 + 4H20
Bischofite Brucite
Single distillation of water samples also is time consuming Accord-ingly an apparatus suitable for distilling several saline samples simul-taneously is needed The apparatus should contain a heat controller to ensure that the temperature required to dehydrate Brucite 350degC is reached
1
vacuum
WUU
(c)
distillation vial 30 cm x 3 cm
liquid nitrogen
condensation vial 16 cm x 25 cm
(b)
(a)
Figure 1 Multi-saline sample distillation apparatus for hydrogen isotope analyses (not to scale)
(a)Micro-Kjeldahl apparatus with six individual heat controls (b)Six heating elements two half-shells each enclosed in a
heat-insulating box and connected to a variable auto trans-former
(c)Glass manifold connected to a vacuum line and distillation-condensation vials
2
APPARATUS
The apparatus in figure 1 as designed consists of a micro-Kjeldahl apparatus with six recesses equipped with individual heat controls (fig la) Another six heating units each consisting of two half-shell heating ele-ments were build on top of the six recesses (fig lb) The heating elements were enclosed in a box of heat-insulating material and connected to a variable autotransformer to control the temperature The variable autotransformer and the heat controls are calibrated to maintain the temperature at the top of the upper heating elements at 400 C and at the bottom of the recesses at 350degC
A glass manifold with six ports and flexi-metal tube was designed to permit connection of the distillation apparatus to a vacuum line (fig lc) The ports were spaced so that two-thirds of the length of the distillation vials fit inside the heating elements with their bottom in the recesses of the micro-Kjeldahl apparatus Each distillation vial has an arm longer than the width of the distillation apparatus connected to a condensation vial (fig lc)
METHOD AND RESULTS
The distillation vials were filled up to two-thirds of their height with glass beads A pipette was used to inject a 2-ml water sample into the bottom of each vial Six small dewars filled with liquid nitrogen were placed so that the bottom of the distillation vials were barely im-mersed in liquid nitrogen After at least 3 minutes and after ensuring that water samples were frozen the vials were evacuated
The dewars containing liquid nitrogen were removed and the manifold-distillation unit was adjusted via the flexi-metal tube so that the vials containing samples were placed inside the designated recesses of the heat-ing apparatus The upper parts of the vials were heated to 400degC before the bottoms were heated in order to flash to steam completely any saline water splashed on the beads and walls of vial The temperature was moni-tored for 15 minutes while the condensation vials were immersed in liquid nitrogen After ensuring that distillation was completed the condensation vials were removed the frozen distilled water was thawed and the distilled water samples were stored
To test the effect 5 distillation on the measured hydrogen isotopic composition of water SDmdash ofdeionized water was measured before and after distillation The composition of sea water (Borchert and Muir 1964 p 186) was simulated by dissolving H -free salts in deionized water of known SD After distillation SD of the prepared sea water was measured to detect the effect of presence of salts on the oacuteD of the distilled water Six samples of the deionized water and the prepared sea water were distilled Two groups of samples were distilled to detect the variation due to the analytical procedure
1 (SD SMOW per mil= [(R sample R standard)-1] 1000 where R = DH (Hydrogen mass-2Hydrogen mass-1) and the standard is Standard Mean Ocean Water (SMOW)
3
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
50272 -101 3 Recipients Accession No1 REPORT NOREPORT DOCUMENTATION
PAGE USGSWRDWRI81-25 4 Title and Subtitle 5 Report Date
April 1981MULTI-SALINE SAMPLE DISTILLATION APPARATUS FOR HYDROGEN ISOTOPE ANALYSES DESIGN AND ACCURACY
6
7 Author(s) 8 Performing Organization Rept No
Afifa A Hassan 9 Performing Organization Name and Address 10 ProjectTaskWork Unit No
U S Geological Survey Water Resources Division 11 Contract(C) or Grant(G) No
12201 Sunrise Valley Drive Mail Stop 432 Reston Virginia 22092 (C)
(G)
12 Sponsoring Organization Name and Address 13 Type of Report amp Period Covered
U S Geological Survey Water Resources Division 12201 Sunrise Valley Drive Mail Stop 432
14 Reston Virginia 22092
15 Supplementary Notes
16 Abstract (Limit 200 words)
A distillation apparatus for saline water samples was designed and tested Six samples may be distilled simultaneously The temperature was maintained at 400degC to ensure complete dehydration of the precipitating salts Consequently the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated
17 Document Analysis a Descriptors
Desalination Apparatus Stable Isotopes Hydrogen
b IdentifiersOpen-Ended Terms
c COSATI FieldGroup
18 Availability Statement
No restriction on distribution Prepared for NTIS by U S Geological Survey WRD
19 Security Class (This Report)
Unclassified_ 20 Security Class (This Page)
Unclassified
21 No of Pages
4 22 Price
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35) Department of Commerce
(See ANSImdashZ3918) See Instructions on Reverse
IVIbdquoLTI-SALIE SA VPLE DISTILLATIO APPARATUS FOR HYDROGE ISOTO 1 ANALYSES
DESIG AD ACCJRACY
By AF1FA AFIFI HASSAN
US GEOLOGICAL SURVEY
Water-Resources Investigations 81-25
1981
UITED STATES DEPARTMENT OF TH INTERIOR JAMES G WA I I Secretary
GEOLOGICAL SURVEY
Doyle G Frederick Acting Director
For additional information write to
Chief Hydrologist US Geological Survey WRD 432 National Center Reston Virginia 22092
CONTENTS
Page
Abstract 1
Introduction
Method and Results 34
1
Apparatus 3
Conclusions 4
References 4
ILLUSTRATIONS
Page
Figure 1 Sketch showing multi-saline sample dis-tillation apparatus for hydrogen isotope analyses
iii
2
MULTI-SALINE SAMPLE DISTILLATION APPARATUS FOR HYDROGEN ISOTOPE ANALYSES
DESIGN AND ACCURACY
By Afifa Afifi Hassan
ABSTRACT
A distillation apparatus for saline water samples was designed and tested Six samples may be distilled simultaneously The temperature was maintained at 400degC to ensure complete dehydration of the precipita-ting salts Consequently the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated
INTRODUCTION
The most commonly used method to convert water to hydrogen for stable isotope analyses is the reaction with hot uranium (Bigeleisen and others 1952) However water samples containing more than 1000 ppm salts require distillation before they are injected into the sample preparation vacuum line to minimize memory effects resulting from precipitation of dehydrated salts Distillation vials containing glass beads (fig 1) are used to distill water samples one at a time without a heat controller (Truesdell personal oral communication to Tyler Coplen 1978) The temperature is unknown
The problem of concern is that upon evaporation during distillation hydrated salts that precipitate may not be completely dehydrated For example MgC12 6H20 (Bischofite) KC1MgC12 6H20 (Carnallite) MgSO4 7H20 (Epsomite) and MgSO4 H2O (Kieserite) may precipitate To determine the hydrogen isotopic compostion of the water accurately all the water and OH groups must be driven out of these salts Most of the water-containing salts except Bischofite completely dehydrate at 200degC or less Bischo-fite dehydrates in two steps The first step may form Brucite Mg(OH)2 which in turn dehydrates at 350degC Another problem of concern is the loss of HC1 formed during dehydration of the magnesium chloride salts An example of the reaction is as follows
MgCl2 6H2C----40- 2 HC1 + Mg(OH)2 + 4H20
Bischofite Brucite
Single distillation of water samples also is time consuming Accord-ingly an apparatus suitable for distilling several saline samples simul-taneously is needed The apparatus should contain a heat controller to ensure that the temperature required to dehydrate Brucite 350degC is reached
1
vacuum
WUU
(c)
distillation vial 30 cm x 3 cm
liquid nitrogen
condensation vial 16 cm x 25 cm
(b)
(a)
Figure 1 Multi-saline sample distillation apparatus for hydrogen isotope analyses (not to scale)
(a)Micro-Kjeldahl apparatus with six individual heat controls (b)Six heating elements two half-shells each enclosed in a
heat-insulating box and connected to a variable auto trans-former
(c)Glass manifold connected to a vacuum line and distillation-condensation vials
2
APPARATUS
The apparatus in figure 1 as designed consists of a micro-Kjeldahl apparatus with six recesses equipped with individual heat controls (fig la) Another six heating units each consisting of two half-shell heating ele-ments were build on top of the six recesses (fig lb) The heating elements were enclosed in a box of heat-insulating material and connected to a variable autotransformer to control the temperature The variable autotransformer and the heat controls are calibrated to maintain the temperature at the top of the upper heating elements at 400 C and at the bottom of the recesses at 350degC
A glass manifold with six ports and flexi-metal tube was designed to permit connection of the distillation apparatus to a vacuum line (fig lc) The ports were spaced so that two-thirds of the length of the distillation vials fit inside the heating elements with their bottom in the recesses of the micro-Kjeldahl apparatus Each distillation vial has an arm longer than the width of the distillation apparatus connected to a condensation vial (fig lc)
METHOD AND RESULTS
The distillation vials were filled up to two-thirds of their height with glass beads A pipette was used to inject a 2-ml water sample into the bottom of each vial Six small dewars filled with liquid nitrogen were placed so that the bottom of the distillation vials were barely im-mersed in liquid nitrogen After at least 3 minutes and after ensuring that water samples were frozen the vials were evacuated
The dewars containing liquid nitrogen were removed and the manifold-distillation unit was adjusted via the flexi-metal tube so that the vials containing samples were placed inside the designated recesses of the heat-ing apparatus The upper parts of the vials were heated to 400degC before the bottoms were heated in order to flash to steam completely any saline water splashed on the beads and walls of vial The temperature was moni-tored for 15 minutes while the condensation vials were immersed in liquid nitrogen After ensuring that distillation was completed the condensation vials were removed the frozen distilled water was thawed and the distilled water samples were stored
To test the effect 5 distillation on the measured hydrogen isotopic composition of water SDmdash ofdeionized water was measured before and after distillation The composition of sea water (Borchert and Muir 1964 p 186) was simulated by dissolving H -free salts in deionized water of known SD After distillation SD of the prepared sea water was measured to detect the effect of presence of salts on the oacuteD of the distilled water Six samples of the deionized water and the prepared sea water were distilled Two groups of samples were distilled to detect the variation due to the analytical procedure
1 (SD SMOW per mil= [(R sample R standard)-1] 1000 where R = DH (Hydrogen mass-2Hydrogen mass-1) and the standard is Standard Mean Ocean Water (SMOW)
3
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
IVIbdquoLTI-SALIE SA VPLE DISTILLATIO APPARATUS FOR HYDROGE ISOTO 1 ANALYSES
DESIG AD ACCJRACY
By AF1FA AFIFI HASSAN
US GEOLOGICAL SURVEY
Water-Resources Investigations 81-25
1981
UITED STATES DEPARTMENT OF TH INTERIOR JAMES G WA I I Secretary
GEOLOGICAL SURVEY
Doyle G Frederick Acting Director
For additional information write to
Chief Hydrologist US Geological Survey WRD 432 National Center Reston Virginia 22092
CONTENTS
Page
Abstract 1
Introduction
Method and Results 34
1
Apparatus 3
Conclusions 4
References 4
ILLUSTRATIONS
Page
Figure 1 Sketch showing multi-saline sample dis-tillation apparatus for hydrogen isotope analyses
iii
2
MULTI-SALINE SAMPLE DISTILLATION APPARATUS FOR HYDROGEN ISOTOPE ANALYSES
DESIGN AND ACCURACY
By Afifa Afifi Hassan
ABSTRACT
A distillation apparatus for saline water samples was designed and tested Six samples may be distilled simultaneously The temperature was maintained at 400degC to ensure complete dehydration of the precipita-ting salts Consequently the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated
INTRODUCTION
The most commonly used method to convert water to hydrogen for stable isotope analyses is the reaction with hot uranium (Bigeleisen and others 1952) However water samples containing more than 1000 ppm salts require distillation before they are injected into the sample preparation vacuum line to minimize memory effects resulting from precipitation of dehydrated salts Distillation vials containing glass beads (fig 1) are used to distill water samples one at a time without a heat controller (Truesdell personal oral communication to Tyler Coplen 1978) The temperature is unknown
The problem of concern is that upon evaporation during distillation hydrated salts that precipitate may not be completely dehydrated For example MgC12 6H20 (Bischofite) KC1MgC12 6H20 (Carnallite) MgSO4 7H20 (Epsomite) and MgSO4 H2O (Kieserite) may precipitate To determine the hydrogen isotopic compostion of the water accurately all the water and OH groups must be driven out of these salts Most of the water-containing salts except Bischofite completely dehydrate at 200degC or less Bischo-fite dehydrates in two steps The first step may form Brucite Mg(OH)2 which in turn dehydrates at 350degC Another problem of concern is the loss of HC1 formed during dehydration of the magnesium chloride salts An example of the reaction is as follows
MgCl2 6H2C----40- 2 HC1 + Mg(OH)2 + 4H20
Bischofite Brucite
Single distillation of water samples also is time consuming Accord-ingly an apparatus suitable for distilling several saline samples simul-taneously is needed The apparatus should contain a heat controller to ensure that the temperature required to dehydrate Brucite 350degC is reached
1
vacuum
WUU
(c)
distillation vial 30 cm x 3 cm
liquid nitrogen
condensation vial 16 cm x 25 cm
(b)
(a)
Figure 1 Multi-saline sample distillation apparatus for hydrogen isotope analyses (not to scale)
(a)Micro-Kjeldahl apparatus with six individual heat controls (b)Six heating elements two half-shells each enclosed in a
heat-insulating box and connected to a variable auto trans-former
(c)Glass manifold connected to a vacuum line and distillation-condensation vials
2
APPARATUS
The apparatus in figure 1 as designed consists of a micro-Kjeldahl apparatus with six recesses equipped with individual heat controls (fig la) Another six heating units each consisting of two half-shell heating ele-ments were build on top of the six recesses (fig lb) The heating elements were enclosed in a box of heat-insulating material and connected to a variable autotransformer to control the temperature The variable autotransformer and the heat controls are calibrated to maintain the temperature at the top of the upper heating elements at 400 C and at the bottom of the recesses at 350degC
A glass manifold with six ports and flexi-metal tube was designed to permit connection of the distillation apparatus to a vacuum line (fig lc) The ports were spaced so that two-thirds of the length of the distillation vials fit inside the heating elements with their bottom in the recesses of the micro-Kjeldahl apparatus Each distillation vial has an arm longer than the width of the distillation apparatus connected to a condensation vial (fig lc)
METHOD AND RESULTS
The distillation vials were filled up to two-thirds of their height with glass beads A pipette was used to inject a 2-ml water sample into the bottom of each vial Six small dewars filled with liquid nitrogen were placed so that the bottom of the distillation vials were barely im-mersed in liquid nitrogen After at least 3 minutes and after ensuring that water samples were frozen the vials were evacuated
The dewars containing liquid nitrogen were removed and the manifold-distillation unit was adjusted via the flexi-metal tube so that the vials containing samples were placed inside the designated recesses of the heat-ing apparatus The upper parts of the vials were heated to 400degC before the bottoms were heated in order to flash to steam completely any saline water splashed on the beads and walls of vial The temperature was moni-tored for 15 minutes while the condensation vials were immersed in liquid nitrogen After ensuring that distillation was completed the condensation vials were removed the frozen distilled water was thawed and the distilled water samples were stored
To test the effect 5 distillation on the measured hydrogen isotopic composition of water SDmdash ofdeionized water was measured before and after distillation The composition of sea water (Borchert and Muir 1964 p 186) was simulated by dissolving H -free salts in deionized water of known SD After distillation SD of the prepared sea water was measured to detect the effect of presence of salts on the oacuteD of the distilled water Six samples of the deionized water and the prepared sea water were distilled Two groups of samples were distilled to detect the variation due to the analytical procedure
1 (SD SMOW per mil= [(R sample R standard)-1] 1000 where R = DH (Hydrogen mass-2Hydrogen mass-1) and the standard is Standard Mean Ocean Water (SMOW)
3
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
UITED STATES DEPARTMENT OF TH INTERIOR JAMES G WA I I Secretary
GEOLOGICAL SURVEY
Doyle G Frederick Acting Director
For additional information write to
Chief Hydrologist US Geological Survey WRD 432 National Center Reston Virginia 22092
CONTENTS
Page
Abstract 1
Introduction
Method and Results 34
1
Apparatus 3
Conclusions 4
References 4
ILLUSTRATIONS
Page
Figure 1 Sketch showing multi-saline sample dis-tillation apparatus for hydrogen isotope analyses
iii
2
MULTI-SALINE SAMPLE DISTILLATION APPARATUS FOR HYDROGEN ISOTOPE ANALYSES
DESIGN AND ACCURACY
By Afifa Afifi Hassan
ABSTRACT
A distillation apparatus for saline water samples was designed and tested Six samples may be distilled simultaneously The temperature was maintained at 400degC to ensure complete dehydration of the precipita-ting salts Consequently the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated
INTRODUCTION
The most commonly used method to convert water to hydrogen for stable isotope analyses is the reaction with hot uranium (Bigeleisen and others 1952) However water samples containing more than 1000 ppm salts require distillation before they are injected into the sample preparation vacuum line to minimize memory effects resulting from precipitation of dehydrated salts Distillation vials containing glass beads (fig 1) are used to distill water samples one at a time without a heat controller (Truesdell personal oral communication to Tyler Coplen 1978) The temperature is unknown
The problem of concern is that upon evaporation during distillation hydrated salts that precipitate may not be completely dehydrated For example MgC12 6H20 (Bischofite) KC1MgC12 6H20 (Carnallite) MgSO4 7H20 (Epsomite) and MgSO4 H2O (Kieserite) may precipitate To determine the hydrogen isotopic compostion of the water accurately all the water and OH groups must be driven out of these salts Most of the water-containing salts except Bischofite completely dehydrate at 200degC or less Bischo-fite dehydrates in two steps The first step may form Brucite Mg(OH)2 which in turn dehydrates at 350degC Another problem of concern is the loss of HC1 formed during dehydration of the magnesium chloride salts An example of the reaction is as follows
MgCl2 6H2C----40- 2 HC1 + Mg(OH)2 + 4H20
Bischofite Brucite
Single distillation of water samples also is time consuming Accord-ingly an apparatus suitable for distilling several saline samples simul-taneously is needed The apparatus should contain a heat controller to ensure that the temperature required to dehydrate Brucite 350degC is reached
1
vacuum
WUU
(c)
distillation vial 30 cm x 3 cm
liquid nitrogen
condensation vial 16 cm x 25 cm
(b)
(a)
Figure 1 Multi-saline sample distillation apparatus for hydrogen isotope analyses (not to scale)
(a)Micro-Kjeldahl apparatus with six individual heat controls (b)Six heating elements two half-shells each enclosed in a
heat-insulating box and connected to a variable auto trans-former
(c)Glass manifold connected to a vacuum line and distillation-condensation vials
2
APPARATUS
The apparatus in figure 1 as designed consists of a micro-Kjeldahl apparatus with six recesses equipped with individual heat controls (fig la) Another six heating units each consisting of two half-shell heating ele-ments were build on top of the six recesses (fig lb) The heating elements were enclosed in a box of heat-insulating material and connected to a variable autotransformer to control the temperature The variable autotransformer and the heat controls are calibrated to maintain the temperature at the top of the upper heating elements at 400 C and at the bottom of the recesses at 350degC
A glass manifold with six ports and flexi-metal tube was designed to permit connection of the distillation apparatus to a vacuum line (fig lc) The ports were spaced so that two-thirds of the length of the distillation vials fit inside the heating elements with their bottom in the recesses of the micro-Kjeldahl apparatus Each distillation vial has an arm longer than the width of the distillation apparatus connected to a condensation vial (fig lc)
METHOD AND RESULTS
The distillation vials were filled up to two-thirds of their height with glass beads A pipette was used to inject a 2-ml water sample into the bottom of each vial Six small dewars filled with liquid nitrogen were placed so that the bottom of the distillation vials were barely im-mersed in liquid nitrogen After at least 3 minutes and after ensuring that water samples were frozen the vials were evacuated
The dewars containing liquid nitrogen were removed and the manifold-distillation unit was adjusted via the flexi-metal tube so that the vials containing samples were placed inside the designated recesses of the heat-ing apparatus The upper parts of the vials were heated to 400degC before the bottoms were heated in order to flash to steam completely any saline water splashed on the beads and walls of vial The temperature was moni-tored for 15 minutes while the condensation vials were immersed in liquid nitrogen After ensuring that distillation was completed the condensation vials were removed the frozen distilled water was thawed and the distilled water samples were stored
To test the effect 5 distillation on the measured hydrogen isotopic composition of water SDmdash ofdeionized water was measured before and after distillation The composition of sea water (Borchert and Muir 1964 p 186) was simulated by dissolving H -free salts in deionized water of known SD After distillation SD of the prepared sea water was measured to detect the effect of presence of salts on the oacuteD of the distilled water Six samples of the deionized water and the prepared sea water were distilled Two groups of samples were distilled to detect the variation due to the analytical procedure
1 (SD SMOW per mil= [(R sample R standard)-1] 1000 where R = DH (Hydrogen mass-2Hydrogen mass-1) and the standard is Standard Mean Ocean Water (SMOW)
3
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
CONTENTS
Page
Abstract 1
Introduction
Method and Results 34
1
Apparatus 3
Conclusions 4
References 4
ILLUSTRATIONS
Page
Figure 1 Sketch showing multi-saline sample dis-tillation apparatus for hydrogen isotope analyses
iii
2
MULTI-SALINE SAMPLE DISTILLATION APPARATUS FOR HYDROGEN ISOTOPE ANALYSES
DESIGN AND ACCURACY
By Afifa Afifi Hassan
ABSTRACT
A distillation apparatus for saline water samples was designed and tested Six samples may be distilled simultaneously The temperature was maintained at 400degC to ensure complete dehydration of the precipita-ting salts Consequently the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated
INTRODUCTION
The most commonly used method to convert water to hydrogen for stable isotope analyses is the reaction with hot uranium (Bigeleisen and others 1952) However water samples containing more than 1000 ppm salts require distillation before they are injected into the sample preparation vacuum line to minimize memory effects resulting from precipitation of dehydrated salts Distillation vials containing glass beads (fig 1) are used to distill water samples one at a time without a heat controller (Truesdell personal oral communication to Tyler Coplen 1978) The temperature is unknown
The problem of concern is that upon evaporation during distillation hydrated salts that precipitate may not be completely dehydrated For example MgC12 6H20 (Bischofite) KC1MgC12 6H20 (Carnallite) MgSO4 7H20 (Epsomite) and MgSO4 H2O (Kieserite) may precipitate To determine the hydrogen isotopic compostion of the water accurately all the water and OH groups must be driven out of these salts Most of the water-containing salts except Bischofite completely dehydrate at 200degC or less Bischo-fite dehydrates in two steps The first step may form Brucite Mg(OH)2 which in turn dehydrates at 350degC Another problem of concern is the loss of HC1 formed during dehydration of the magnesium chloride salts An example of the reaction is as follows
MgCl2 6H2C----40- 2 HC1 + Mg(OH)2 + 4H20
Bischofite Brucite
Single distillation of water samples also is time consuming Accord-ingly an apparatus suitable for distilling several saline samples simul-taneously is needed The apparatus should contain a heat controller to ensure that the temperature required to dehydrate Brucite 350degC is reached
1
vacuum
WUU
(c)
distillation vial 30 cm x 3 cm
liquid nitrogen
condensation vial 16 cm x 25 cm
(b)
(a)
Figure 1 Multi-saline sample distillation apparatus for hydrogen isotope analyses (not to scale)
(a)Micro-Kjeldahl apparatus with six individual heat controls (b)Six heating elements two half-shells each enclosed in a
heat-insulating box and connected to a variable auto trans-former
(c)Glass manifold connected to a vacuum line and distillation-condensation vials
2
APPARATUS
The apparatus in figure 1 as designed consists of a micro-Kjeldahl apparatus with six recesses equipped with individual heat controls (fig la) Another six heating units each consisting of two half-shell heating ele-ments were build on top of the six recesses (fig lb) The heating elements were enclosed in a box of heat-insulating material and connected to a variable autotransformer to control the temperature The variable autotransformer and the heat controls are calibrated to maintain the temperature at the top of the upper heating elements at 400 C and at the bottom of the recesses at 350degC
A glass manifold with six ports and flexi-metal tube was designed to permit connection of the distillation apparatus to a vacuum line (fig lc) The ports were spaced so that two-thirds of the length of the distillation vials fit inside the heating elements with their bottom in the recesses of the micro-Kjeldahl apparatus Each distillation vial has an arm longer than the width of the distillation apparatus connected to a condensation vial (fig lc)
METHOD AND RESULTS
The distillation vials were filled up to two-thirds of their height with glass beads A pipette was used to inject a 2-ml water sample into the bottom of each vial Six small dewars filled with liquid nitrogen were placed so that the bottom of the distillation vials were barely im-mersed in liquid nitrogen After at least 3 minutes and after ensuring that water samples were frozen the vials were evacuated
The dewars containing liquid nitrogen were removed and the manifold-distillation unit was adjusted via the flexi-metal tube so that the vials containing samples were placed inside the designated recesses of the heat-ing apparatus The upper parts of the vials were heated to 400degC before the bottoms were heated in order to flash to steam completely any saline water splashed on the beads and walls of vial The temperature was moni-tored for 15 minutes while the condensation vials were immersed in liquid nitrogen After ensuring that distillation was completed the condensation vials were removed the frozen distilled water was thawed and the distilled water samples were stored
To test the effect 5 distillation on the measured hydrogen isotopic composition of water SDmdash ofdeionized water was measured before and after distillation The composition of sea water (Borchert and Muir 1964 p 186) was simulated by dissolving H -free salts in deionized water of known SD After distillation SD of the prepared sea water was measured to detect the effect of presence of salts on the oacuteD of the distilled water Six samples of the deionized water and the prepared sea water were distilled Two groups of samples were distilled to detect the variation due to the analytical procedure
1 (SD SMOW per mil= [(R sample R standard)-1] 1000 where R = DH (Hydrogen mass-2Hydrogen mass-1) and the standard is Standard Mean Ocean Water (SMOW)
3
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
MULTI-SALINE SAMPLE DISTILLATION APPARATUS FOR HYDROGEN ISOTOPE ANALYSES
DESIGN AND ACCURACY
By Afifa Afifi Hassan
ABSTRACT
A distillation apparatus for saline water samples was designed and tested Six samples may be distilled simultaneously The temperature was maintained at 400degC to ensure complete dehydration of the precipita-ting salts Consequently the error in the measured ratio of stable hydrogen isotopes resulting from incomplete dehydration of hydrated salts during distillation was eliminated
INTRODUCTION
The most commonly used method to convert water to hydrogen for stable isotope analyses is the reaction with hot uranium (Bigeleisen and others 1952) However water samples containing more than 1000 ppm salts require distillation before they are injected into the sample preparation vacuum line to minimize memory effects resulting from precipitation of dehydrated salts Distillation vials containing glass beads (fig 1) are used to distill water samples one at a time without a heat controller (Truesdell personal oral communication to Tyler Coplen 1978) The temperature is unknown
The problem of concern is that upon evaporation during distillation hydrated salts that precipitate may not be completely dehydrated For example MgC12 6H20 (Bischofite) KC1MgC12 6H20 (Carnallite) MgSO4 7H20 (Epsomite) and MgSO4 H2O (Kieserite) may precipitate To determine the hydrogen isotopic compostion of the water accurately all the water and OH groups must be driven out of these salts Most of the water-containing salts except Bischofite completely dehydrate at 200degC or less Bischo-fite dehydrates in two steps The first step may form Brucite Mg(OH)2 which in turn dehydrates at 350degC Another problem of concern is the loss of HC1 formed during dehydration of the magnesium chloride salts An example of the reaction is as follows
MgCl2 6H2C----40- 2 HC1 + Mg(OH)2 + 4H20
Bischofite Brucite
Single distillation of water samples also is time consuming Accord-ingly an apparatus suitable for distilling several saline samples simul-taneously is needed The apparatus should contain a heat controller to ensure that the temperature required to dehydrate Brucite 350degC is reached
1
vacuum
WUU
(c)
distillation vial 30 cm x 3 cm
liquid nitrogen
condensation vial 16 cm x 25 cm
(b)
(a)
Figure 1 Multi-saline sample distillation apparatus for hydrogen isotope analyses (not to scale)
(a)Micro-Kjeldahl apparatus with six individual heat controls (b)Six heating elements two half-shells each enclosed in a
heat-insulating box and connected to a variable auto trans-former
(c)Glass manifold connected to a vacuum line and distillation-condensation vials
2
APPARATUS
The apparatus in figure 1 as designed consists of a micro-Kjeldahl apparatus with six recesses equipped with individual heat controls (fig la) Another six heating units each consisting of two half-shell heating ele-ments were build on top of the six recesses (fig lb) The heating elements were enclosed in a box of heat-insulating material and connected to a variable autotransformer to control the temperature The variable autotransformer and the heat controls are calibrated to maintain the temperature at the top of the upper heating elements at 400 C and at the bottom of the recesses at 350degC
A glass manifold with six ports and flexi-metal tube was designed to permit connection of the distillation apparatus to a vacuum line (fig lc) The ports were spaced so that two-thirds of the length of the distillation vials fit inside the heating elements with their bottom in the recesses of the micro-Kjeldahl apparatus Each distillation vial has an arm longer than the width of the distillation apparatus connected to a condensation vial (fig lc)
METHOD AND RESULTS
The distillation vials were filled up to two-thirds of their height with glass beads A pipette was used to inject a 2-ml water sample into the bottom of each vial Six small dewars filled with liquid nitrogen were placed so that the bottom of the distillation vials were barely im-mersed in liquid nitrogen After at least 3 minutes and after ensuring that water samples were frozen the vials were evacuated
The dewars containing liquid nitrogen were removed and the manifold-distillation unit was adjusted via the flexi-metal tube so that the vials containing samples were placed inside the designated recesses of the heat-ing apparatus The upper parts of the vials were heated to 400degC before the bottoms were heated in order to flash to steam completely any saline water splashed on the beads and walls of vial The temperature was moni-tored for 15 minutes while the condensation vials were immersed in liquid nitrogen After ensuring that distillation was completed the condensation vials were removed the frozen distilled water was thawed and the distilled water samples were stored
To test the effect 5 distillation on the measured hydrogen isotopic composition of water SDmdash ofdeionized water was measured before and after distillation The composition of sea water (Borchert and Muir 1964 p 186) was simulated by dissolving H -free salts in deionized water of known SD After distillation SD of the prepared sea water was measured to detect the effect of presence of salts on the oacuteD of the distilled water Six samples of the deionized water and the prepared sea water were distilled Two groups of samples were distilled to detect the variation due to the analytical procedure
1 (SD SMOW per mil= [(R sample R standard)-1] 1000 where R = DH (Hydrogen mass-2Hydrogen mass-1) and the standard is Standard Mean Ocean Water (SMOW)
3
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
vacuum
WUU
(c)
distillation vial 30 cm x 3 cm
liquid nitrogen
condensation vial 16 cm x 25 cm
(b)
(a)
Figure 1 Multi-saline sample distillation apparatus for hydrogen isotope analyses (not to scale)
(a)Micro-Kjeldahl apparatus with six individual heat controls (b)Six heating elements two half-shells each enclosed in a
heat-insulating box and connected to a variable auto trans-former
(c)Glass manifold connected to a vacuum line and distillation-condensation vials
2
APPARATUS
The apparatus in figure 1 as designed consists of a micro-Kjeldahl apparatus with six recesses equipped with individual heat controls (fig la) Another six heating units each consisting of two half-shell heating ele-ments were build on top of the six recesses (fig lb) The heating elements were enclosed in a box of heat-insulating material and connected to a variable autotransformer to control the temperature The variable autotransformer and the heat controls are calibrated to maintain the temperature at the top of the upper heating elements at 400 C and at the bottom of the recesses at 350degC
A glass manifold with six ports and flexi-metal tube was designed to permit connection of the distillation apparatus to a vacuum line (fig lc) The ports were spaced so that two-thirds of the length of the distillation vials fit inside the heating elements with their bottom in the recesses of the micro-Kjeldahl apparatus Each distillation vial has an arm longer than the width of the distillation apparatus connected to a condensation vial (fig lc)
METHOD AND RESULTS
The distillation vials were filled up to two-thirds of their height with glass beads A pipette was used to inject a 2-ml water sample into the bottom of each vial Six small dewars filled with liquid nitrogen were placed so that the bottom of the distillation vials were barely im-mersed in liquid nitrogen After at least 3 minutes and after ensuring that water samples were frozen the vials were evacuated
The dewars containing liquid nitrogen were removed and the manifold-distillation unit was adjusted via the flexi-metal tube so that the vials containing samples were placed inside the designated recesses of the heat-ing apparatus The upper parts of the vials were heated to 400degC before the bottoms were heated in order to flash to steam completely any saline water splashed on the beads and walls of vial The temperature was moni-tored for 15 minutes while the condensation vials were immersed in liquid nitrogen After ensuring that distillation was completed the condensation vials were removed the frozen distilled water was thawed and the distilled water samples were stored
To test the effect 5 distillation on the measured hydrogen isotopic composition of water SDmdash ofdeionized water was measured before and after distillation The composition of sea water (Borchert and Muir 1964 p 186) was simulated by dissolving H -free salts in deionized water of known SD After distillation SD of the prepared sea water was measured to detect the effect of presence of salts on the oacuteD of the distilled water Six samples of the deionized water and the prepared sea water were distilled Two groups of samples were distilled to detect the variation due to the analytical procedure
1 (SD SMOW per mil= [(R sample R standard)-1] 1000 where R = DH (Hydrogen mass-2Hydrogen mass-1) and the standard is Standard Mean Ocean Water (SMOW)
3
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
APPARATUS
The apparatus in figure 1 as designed consists of a micro-Kjeldahl apparatus with six recesses equipped with individual heat controls (fig la) Another six heating units each consisting of two half-shell heating ele-ments were build on top of the six recesses (fig lb) The heating elements were enclosed in a box of heat-insulating material and connected to a variable autotransformer to control the temperature The variable autotransformer and the heat controls are calibrated to maintain the temperature at the top of the upper heating elements at 400 C and at the bottom of the recesses at 350degC
A glass manifold with six ports and flexi-metal tube was designed to permit connection of the distillation apparatus to a vacuum line (fig lc) The ports were spaced so that two-thirds of the length of the distillation vials fit inside the heating elements with their bottom in the recesses of the micro-Kjeldahl apparatus Each distillation vial has an arm longer than the width of the distillation apparatus connected to a condensation vial (fig lc)
METHOD AND RESULTS
The distillation vials were filled up to two-thirds of their height with glass beads A pipette was used to inject a 2-ml water sample into the bottom of each vial Six small dewars filled with liquid nitrogen were placed so that the bottom of the distillation vials were barely im-mersed in liquid nitrogen After at least 3 minutes and after ensuring that water samples were frozen the vials were evacuated
The dewars containing liquid nitrogen were removed and the manifold-distillation unit was adjusted via the flexi-metal tube so that the vials containing samples were placed inside the designated recesses of the heat-ing apparatus The upper parts of the vials were heated to 400degC before the bottoms were heated in order to flash to steam completely any saline water splashed on the beads and walls of vial The temperature was moni-tored for 15 minutes while the condensation vials were immersed in liquid nitrogen After ensuring that distillation was completed the condensation vials were removed the frozen distilled water was thawed and the distilled water samples were stored
To test the effect 5 distillation on the measured hydrogen isotopic composition of water SDmdash ofdeionized water was measured before and after distillation The composition of sea water (Borchert and Muir 1964 p 186) was simulated by dissolving H -free salts in deionized water of known SD After distillation SD of the prepared sea water was measured to detect the effect of presence of salts on the oacuteD of the distilled water Six samples of the deionized water and the prepared sea water were distilled Two groups of samples were distilled to detect the variation due to the analytical procedure
1 (SD SMOW per mil= [(R sample R standard)-1] 1000 where R = DH (Hydrogen mass-2Hydrogen mass-1) and the standard is Standard Mean Ocean Water (SMOW)
3
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
Water samples of each group of distillates deionized water and sea water were converted to hydrogen by reaction with uranium at 800 C under vacuum Two separate conversions of the same sample were done The re-sulting gas was analyzed by a modified double-collector mass spectrometer The measured 6D of the deionized water before distillation was -445 per mil relative to SMOW After distillation the mean (SD was -445 + 06 and -444 + 05 for the deionized water and the prepared sea water re-spectively These results indicate that the standard deviation of the analyses is less than one per mil the accepted precision ofo mass spec-trometer and also that the procedure of distillation at 400 C does not introduce error in the hydrogen isotopic composition of the saline water An analysis of variance also shows no significant differences between re-sults in the 5-percent probability level
CONCLUSIONS
The apparatus is efficient because six water samples can be distilled simultaneously The apparatus also distills sea water with no measureable isotopic fractionation It seems that the HC1 produced during dehydration of Bischofite reacts with other precipitates such as Na CO Accordingly
2 3no error was detected in the present test
The apparatus should also be satisfactory for distilling very saline brines because during these distillation experiments a stage was reached where the solution was very saline Accordingly a simulated brine water was not tested However the new apparatus has been used satisfactorily to distill the natural brine samples sent to the laboratory during the past year
REFERENCES
Bigeleisen Jacob Perlman ML and Prosser HC 1952 Conversion of hydrogenic materials to hydrogen for isotopic analysis Analytical Chemistry v 24 no 8 p1356-1357
Borchert Herman and Muir RO 1964 Salt deposits D Van Norstrand Co Ltd London 338 p
US GOVERNMENT PRINTING OFFICE 1981 -341-614 247
4
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
---
4 bull
bull OEMA 11 -1 9 - bull z
- bull - -1 - 4--- - - bull` bull-- z-- 1 - - bull _ - - bull 47 bull7 -4- - -4bullbull bull-bull - 1-- IC- bull t` bdquoiA-1A bull bull - 1 4 -- -5
bdquo-4bdquo 42 - bulls417si--bull-bull - bull -- A- __1bdquo r4_ i_4 bull7 --A __Sbullbull Yibull - bullbull bull i 4bull bullbull_--bull f- bull - A - -n---i- --17414lsquo4 bull bull i - bull bullbull -4 bullbull 14_ - t- - 7 1 bullbullbull -- fL 4bull -4ft 42 - - 7 bullbull-
bull 4W- --14-bull 7 -- bdquo- bull - -0 - i- bull --- --- -mibdquobullbullbull - 4 bull1bullbullbullbullbull -
bull bullbull-ivr-- bullbullbull bull- bull- jetP
bull -71bullbullbullbullbull
bull f
bull bull bull
bull-- -- -bull - 4g - 5 A bull bull - --_-bdquo - -41 _ bull1 s -1- 7_ i_ bdquo s i bdquo bdquo 4 4 - )- 1bull--17 bull 4
a 1 - - 1 -- -2-bull bull _ 4 72 44- `-bull - _----1yi_rdquo t lsquort bull-bull -7 = - - rbullbull r - --- -ibullbullbull- f bdquo7 t - 4 -bullbull` 1 - --7bull--0-bullbull - - ---` bull si rrw
i - Xi - - bull-bulli- T bull l` -f- Mf - bullbullbull77--1-4----- ------ - - bull _ --4----244tt-m7e ---bdquo-- 7 1bull bull-4-P--40 ---v_-- 1 bull --- 7- 3bdquo-- -bull-bdquo bdquo -- --4 72-3 bull-----bull 1- -41sf l-mdash7-tr -7 f bull -- - 4-731 1 --bullebull ibull-bull----_ibullt-144bull-bulllsquo-_bull bullbullbull7 _- Sbull -- -bull- - bullbull - _ bdquo bull --b -14 -sig-i- - 2 N bullbullbullbull 0 N bull - - -
Si 4 S bullbullbull r - 7bull - 1 74of bull bull -17 N bdquo- Itot4r4 - 4 bull ` 111 _ -4rdquo - x ^ bdquo-rit - 4 s - - r Z12bull
bdquo _ t
-fiekbull57
t
11
` t
tet bull_- - Abull rdquoI - K14_brIlle bull-4 -41t- _ bullt 0 - 2- 4 - bdquo
bulllaquo S Z4 -CI bull-bull - bull - ibdquolsquo--bull --35- - 4
r 17- -L - - bull -i a bull1=- _ _ _-bullbullbullbdquo 4bull e- 4 -f--rdquo -Aibr 4 bull--t-c -bullele bull bullbull bull bullbullbullbull bull sbullbull e Ativ f` - lItte-4
bull74 bull bull bull bull r bull
4 --4 444 -
bull bull bull bull irr r1 bullbullbullbullbull bull _s
- vs- bull bullbdquo
-bull - bull- bull-
ites lsquo bull bull i47
r-bullbullbull-
bdquo -A bullbull
bull1lsquo01
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
USGS LIBRARY RESTON
I I II I I 3 1818 00098894 7
![Data Distillation: Towards Omni-Supervised Learning · Data Distillation model A model A Figure 1. Model Distillation [18] vs. Data Distillation. In data distillation, ensembled predictions](https://img.pdfslide.net/doc/110x75/60a237adb93b13457117b793/data-distillation-towards-omni-supervised-learning-data-distillation-model-a-model.jpg)