Effect of pH value on extraction K D D ( distribution coeff. )
HA o org. aq. HA aq + H 2 O H 3 O + + A -
Slide 7
(b) at pH (a) very acid [H + ] >>K a D=K D (c) [H + ] K
D
Slide 8
Effect of pH value on extraction K D D ( distribution coeff. )
B o org. aq. BH + aq H + + B
Slide 9
(b) at pH (a) very acid [H + ] >>K a D >> K D (c)
[H + ]
HL, ML n >>1 [L - ] is pH dependent C L orignal molar
conc. of HL in organic phase mass balance (5) excess chelator C L
[HL (o) ](6)
Slide 14
(3)(4) (5) (6) (7)
Slide 15
Extraction of Metal Ions with RTIL Extraction of Metal Ions
with RTIL Extraction of Metal Ions with RTIL Extraction of Metal
Ions with RTIL RTIL , , RTIL( 1-butyl-3- methylimidazolium
hexafluorophosphate, [BMIM][PF 6 ]) RTIL . 1.Guor-Tzo Wei*, Zusing
Yang, Chao-Jung Chen, Anal. Chimica, Acta 2003, 488(2), 183.
2.Guor-Tzo Wei*, Jin-Chu Chen, Zusing Yang, J. Chin. Chem. Soc.
2003, 50, 1123.
Slide 16
- : . - : a. supercritical fluid CO 2 b. ionic liquid(IL)
Slide 17
Presidential Green Chemistry Challenge Awards
http://www.epa.gov/greenchemistry/ Mission: To promote innovative
chemical technologies that reduce or eliminate the use or
generation of hazardous substances in the design, manufacture, and
use of chemical products. 1996: Alternative Synthetic Pathways
Award: Monsanto Company, The Catalytic Dehydrogenation of
Diethanolamine Alternative Solvents/Reaction Conditions Award: Dow
Chemical The Development and Commercial Implementation of 100
Percent Carbon Dioxide as an Environmentally Friendly Blowing Agent
f or the Polystyrene Foam Sheet Packaging Market Designing Safer
Chemicals Award: Rohm and Haas Designing an Environmentally Safe
Marine Antifoulant Small Business Award: Donlar Corporation
Production and Use of Thermal Polyaspartic Acid Academic Award :
Prof. Mark Holtzapple, Texas A&M Univ. Conversion of Waste
Biomass to Animal Feed, Chemicals, and Fuels
Slide 18
The Twelve Principles of Green Chemistry* 1.Prevention It is
better to prevent waste than to treat or clean up waste after it
has been created. 2.Atom Economy Synthetic methods should be
designed to maximize the incorporation of all materials used in the
process into the final product. 3.Less Hazardous Chemical Syntheses
Wherever practicable, synthetic methods should be designed to use
and generate substances that possess little or no toxicity to human
health and the environment. 4.Designing Safer Chemicals Chemical
products should be designed to effect their desired function while
minimizing their toxicity. 5.Safer Solvents and Auxiliaries The use
of auxiliary substances (e.g., solvents, separation agents, etc.)
should be made unnecessary wherever possible and innocuous when
used. 6.Design for Energy Efficiency Energy requirements of
chemical processes should be recognized for their environmental and
economic impacts and should be minimized. If possible, synthetic
methods should be conducted at ambient temperature and pressure.
7.Use of Renewable Feedstocks A raw material or feedstock should be
renewable rather than depleting whenever technically and
economically practicable.
Slide 19
8.Reduce Derivatives Unnecessary derivatization (use of
blocking groups, protection/ deprotection, temporary modification
of physical/chemical processes) should be minimized or avoided if
possible, because such steps require additional reagents and can
generate waste. 9.Catalysis Catalytic reagents (as selective as
possible) are superior to stoichiometric reagents. 10.Design for
Degradation Chemical products should be designed so that at the end
of their function they break down into innocuous degradation
products and do not persist in the environment. 11.Real-time
analysis for Pollution Prevention Analytical methodologies need to
be further developed to allow for real-time, in- process monitoring
and control prior to the formation of hazardous substances.
12.Inherently Safer Chemistry for Accident Prevention Substances
and the form of a substance used in a chemical process should be
chosen to minimize the potential for chemical accidents, including
releases, explosions, and fires. *Anastas, P. T.; Warner, J. C.
Green Chemistry: Theory and Practice, Oxford University Press: New
York, 1998, p.30.
Slide 20
What is a Room Temperature Ionic Liquid (RTIL)? (Room
Temperature Molten Salt) Liquid salt consisting of at least one
organic component (cation or anion) with melting point below room
temperature Properties: Negligible vapor pressure High thermal
stability (~250-400C) High viscosity Hydrophobic or hydrophilic
Dissolve many organic, organometallic, and inorganic compounds
RTILs are regarding as Green solvents
Slide 21
Ethyl ammonium nitrate (EtNH + 3 )(NO - 3 ), which has a
melting point of 12C, was first described in 1914. P. Walden, Bull.
Acad. Imper. Sci. (St. Petersburg) 1800 (1914). Osteryoung &
Wilks, late1970, chloroaluminate salts in electrochemistry Sneddon
& Hussey, 1980, groups chloroaluminate salts in
electrochemistry and organometallic researches. After 1990, used as
solvents for synthesis Late 2000, the application in
separation
General syntheses of ionic liquid: Green Chemistry, 2003. 5.
181-186.
Slide 25
Effect of the nature of anion on physical properties of BMIM
salt
-----------------------------------------------------------------------------------
Anionm.p. d Viscosity Conductivity o C g/cm 3 cP (20 o C) S/m
----------------------------------------------------------------------------------
BF 4 - -82(g) 1.17 233 0.17 PF 6 - -8 1.36 312 0.14 Cl - 65 1.10
solid solid CF 3 COO - ~-40(g) 1.21 73 0.32 CF 3 SO 3 - 16 1.29 90
0.37 (CF 3 SO 2 )N - -4 1.43 52 0.39 C 3 F 7 COO - ~-40(g) 1.33
1820.10 C 4 F 9 SO 3 - 20 1.47 373 0.045
----------------------------------------------------------------------------------
(g) Glass transition P.S. viscosity of water 1 cP.
Slide 26
Dissolution of Cellulose with Ionic Liquids R.P. Swatloski,
R.D. Rogers, et al. J.A.C.S. 124 (2002) 4974.
Slide 27
Room-temperature ionic liquids: a novel versatile lubricant
Chengfeng Ye, Weimin Liu, Yunxia Chen and Laigui Yu, Chem. Commun.,
2001, (21), 2244 - 2245 Alkylimidazolium tetrafluoroborates are
promising versatile lubricants for the contact of steel/steel,
steel/aluminium, steel/copper, steel/SiO2, Si3N4/SiO2,
steel/Si(100), steel/sialon ceramics and Si3N4/sialon ceramics;
they show excellent friction reduction, antiwear performance and
high load-carrying capacity
Slide 28
Uses of RTILs in Anal. Chem. Novel solvents in liquid-liquid or
micro extractions Run buffer additives in CE Matrixes in
Matrix-Assisted Laser Desorption Ionization (MALDI) mass
spectrometry Stationary phases in gas-liquid chromatography
Slide 29
Illustration of various equilibra involved in metal ion
extraction with ionic liquid. Extraction of Metal Ions with RTIL
Extraction of Metal Ions with RTIL Extraction of Metal Ions with
RTIL Extraction of Metal Ions with RTIL
Slide 30
colorlessmetal complex (red) dithizone
Slide 31
+ + + Cu 2+ 2H + + + + 2 2 2 Green Blue Violet Yellow Orange
Red Dithizone Oxine PAN
Slide 32
The pH value effect on the extraction of lead ion with
dithizone in ( ) ionic liquid, ( ) chloroform.
Slide 33
Comparing the extraction of copper ions with ionic liquid and
dichloromethane with PAN
Slide 34
The effect of pH value on the extraction efficiencies of metal
ions with dithizone by IL.
Slide 35
The effect of pH value on the extraction efficiencies of metal
ions with PAN by IL.
Slide 36
Hg 2+ Zn 2+ Pb 2+ Ca 2+ Cr 3+ Mn 2+ Cd 2+ As 5+ Co 2+ Ag + The
effect of 100 ppm cation on the extraction of 5 ppm Cu 2+ with
dithizone
Slide 37
SCN - citrate Cl - CO 3 2- PO 4 3- CH 3 COO - The effect of 100
ppm anion on the extraction of 5 ppm Cu 2+ with dithizone
Slide 38
SCN - citrate Cl - CO 3 2- PO 4 3- CH 3 COO - The effect of 100
ppm anion on the extraction of 5 ppm Cu 2+ with PAN
Slide 39
TimesTheoretical Value (ppm) Experimental Value (ppm) Recovery
( ) 510.00 100 1020.00 100 2040.0038.2095.5 2550.0045.7595.8
50100.0099.0099.0 Preconcentration of Pb 2+
Slide 40
Metal ions pHE% Cu(II) Cd(II) 2.7456 0 Ag(I) Cd(II) 1.4389.48 0
Cd(II) Ca(II) 7.0887.2 0 (a) Separation of different metal ions;
(b) Reproducibility of Cadmium ions with reusal [C 4 MIM][PF 6 ]
pHE (%) 3.9843.16 3.8938.42 3.9344.74 4.0143.68 3.9942.63 4.0244.21
3.9946.32 Average = 43.31% RSD = 5.69% (a) (b)
Slide 41
Solute A has a partition coeff. of 1/3 between toluene and
water. Suppose that 100 mL of a 0.010 M aqueous solution A is
extract with toluene. What fraction of A remains in the aqueous
phase (a) if one extraction with 500 mL if performed and (b) if
five extractions with 100 mL are performed?