06 Pretreatment for as With HVG-1

Typical Pretreatment for As by HVG-1

Sample 50mL add HClO4; 1 mLHNO3; 2mL

Heat up, Decompose organic substitute

Treat with white fume of HClO4 and evaporate HNO3 Let it cool, add 6mol/L-HCl

Dissolve salts Add 20W/V%-KI solution; 2.5mL

Fill up to 50mL Let it stand for 30 minuets, As5+ As3+

Measure by HVG-1

Pre-Treatment Method for Hydride Vapor Generation Method (Based on JIS [Japan Industrial Standard] K 0101 for plant waste water)

Put the sample* into 25ml volumetric flask

Add 2.5mL concn. (12mol/L) HCl and 1.25mL 20%-KI solution

Fill the flak with pure water

Let it stand for 30 minuets at room temperature Final concentrations; HCl; 1.0 1.2 mol/L, KI; 1% Same reagents and concentrations should be contained in standard solutions.


Add 20mL (6mol/L) HCl and heat it at 90100 for 10 minuets

After cooling fill the flak with pure water Final concentrations; HCl; ca. 5 mol/L Same reagents and concentrations should be contained in standard solutions


Add 5mL (12mol/L) HCl and 3mL (0.1mol/L) thiourea solution

Fill the flak with pure water

0.1mol/L thiourea solutionDissolve 0.76g Thiourea into 100mL water Final concentrations; HCl; ca. 2.4 mol/L, Thiourea; 0.012mol/mL Same reagents and concentrations should be contained in standard solutions

1Sophisticated preparation of real life samples

Typical pretreatment methods

Wet ashing HCl, HNO3 HNO3 + HCLO4

Dry ashing H2SO4 + Heat by electric furnace (500-600) Alkali fusion

2Typical pretreatment for water samples 1/2

1 . Add 1-5 mL HNO3 (or HCl) to 100mL sample.2 . Heat up to boil for about 10 minutes.3 . After cooling, transfer the sample into 100mL

volumetric-flask and fill it up with pure water.

Typical pretreatment for water samples 2/2

1 . Add 1-5 mL HNO3 (or HCl) to 100mL sample.2 . Heat up to boil and keep heating until the sample

volume decrease to about 15 mL.3 . After cooling, transfer the sample into 100mL

volumetric-flask and fill it up with pure water.

3In case of Citrus leaves 1/5Put dried sample (about 0.1g) into the beaker and weigh it (0.1144g).Add 10mL HNO3(1+1) and 2mL perchloric acid.Decompose it on the sand-bath(about 200. Add 10mL HNO3(1+1) gradually to decompose the organic compounds

completely.

Treat with white fume Let it cool, then add 10mL HCl(1+1)Dissolve the salts on the sand bath (about 100) Let it cool.Transfer the treated sample into the 25mL-volumetric flask.Fill it up with pure water: Sample Solution A.

In case of Citrus leaves 2/5For Na Transfer 5mL of the sample solution A into the 25mL-volmetric flask . Add 5mL Cs(0.5w/v%) solution.Fill it up with water to 25mL.

For K ; Transfer 2mL of the sample solution A into the 100mL-volmetric flask . Transfer 5mL of the above solution into the 25mL-volmetric flask . Add 5mL Cs(0.5w/v%) solution.Fill it up with water to 25mL.

4In case of Citrus leaves 3/5

ResultConcentrationin measured

solution

Concentrationin

citrus leaves

Certified Value

Na 0.1543 ppm 169 ppm 160 20 ppm

K 0.3418 ppm 1.87 % 1.87 0.06%

In case of Citrus leaves 4/5 For Mg Transfer 2mL of the sample solution A into the 100mL-volmetric flask .

Transfer 5mL of the above solution into the 25mL-volmetric flask . Add 0.5mL La(5w/v%) solution.Fill it up with water to 25mL.

For CaTransfer 1mL of the sample solution A into the 100mL-volmetric flask . Add 2mL La(5w/v%) solution.Fill it up with water to 100mL.

5In case of Citrus leaves 5/5RESULT

Concentrationin measured

solution

Concentrationin

citrus leaves

Certified Value

Mg 0.1015 ppm 0.555 % 0.58 0.03 %

Ca 1.424 ppm 3.11 % 3.15 0.10%

Preparation for Hydride Vapor Generation Method 1/3

Put dried sample into the beaker and weigh it (1.000g).Add 10mL HNO3(1+1) and 2mL perchloric acid.Decompose it on the sand-bath(about 200. Add 10mL HNO3(1+1) gradually to decompose the organic

compounds completely.

Treat with white fume Let it cool, then add 20mL HCl(1+1)Dissolve the salts on the sand bath (about 100) Let it cool.Transfer the treated sample into the 100mL-volumetric flask.Fill it up with pure water: Sample Solution A.

6Preparation for Hydride Vapor Generation Method 2/3

Transfer 5mL of the sample solution A into the 50mL-volmetric flask .

Add 10mL HCl(1+1) and KI(10w/v%) solutionFill it up with water to 50mL.Let it stand for 30minuites before measurement.

Preparation for Hydride Vapor Generation Method 3/3

RESULTSSamples Concentration

in solutionConcentration

in solidsamples

Certified Values

CitrusLeaves 3.10 ppb 3.10 ppm 3.1 0.3ppm

Rice Flour2.97 ppb 0.297 ppm 0.29 ppm

PondSediment 2.10 ppb 10.5 ppm 12 2 ppm

7Example of pretreatment of citrus leaves1/8

Take sample and weigh

Example of pretreatment of citrus leaves 2/8

Add 5mL-HNO3 and put on the sand-bath.

Start heating

8Example of pretreatment of citrus leaves 3/8

As the decomposition of the organic compounds proceeds, brown color nitrous acid fume is generated.


Keep heating until the brown fume degrease.

9Example of pretreatment of citrus leaves 5/8

After cooling, add 5mL-HNO3 and 2mL-HCLO4 and heat again.

White fume (perchloric acid) is generated.


Keep heating until almost dryness.

10


Add 20mL-HCl(1+1) to dissolve the salts


Keep heating about 10-20minutes to dissolve the salts completely

After cooling, transfer the solution into the volumetric flask.

11

Alkali fusion method 1/3for elements; Si, Al

for samples; ceramics, minerals, bricks

1 Put the sample into the Pt crucible.

2 Add the flux (Na2CO3 , LiBO2, Na2B4O7, etc. 5-10 folds of sample weight)

Alkali fusion method 2/3

Put the Pt crucible into the ceramic crucible for protecting.

Set the crucible into the electrical furnace(temp.;700-1000 for 0.5-1.0hr.)

12

Alkali fusion method 3/3

After cooling add the diluted HCl to disolve the salt

Transfer the solution into the volmetric-flask made of plastic.

High pressure Teflon vessel

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06 Pretreatment for as With HVG-1