Liquid Anion Exchanger Research Articles

Quantitative Determination of Colorants in Dried Shrimp and Shrimp Paste Using Ion-Exchange Extraction and High Performance Liquid Chromatography

A method is proposed for extraction of colorants from proteinous foods (dried shrimp and shrimp paste) and for their determination by high performance liquid chromatography (HPLC). Water-soluble colors were extracted by liquid-liquid partition with the aid of a liquid anion exchange resin (Amberlite LA-2) after elution with an ethanol-ammonia mixture from the sample, where colors were released from protein. Colors were then re-extracted from the resin layer into an aqueous solution, followed by HPLC determination. The HPLC conditions using a reverse-phase partition type column (Zorbax C8) and ammonium acetate as eluant, were acceptable for various kinds of colorants. The proposed method gave recovery values of more than 62.0% for color at 100 ppm and of more than 76.0% for color at 1,000 ppm; an actual survey of colorants was carried out for 44 samples.

Solvent Extraction Separation of Zirconium (iv) With Anberlite LA - 1 From Citrate Solutions

Abstract Zirconium was quantitatively extracted with 8 × 10−2 M of Amberlite LA-1 or LA-2 xylene from 0.001 M citric acid at pH 3.5 and it was stripped from the organic phase with 2 M hydrochloric acid and was determined spectrophotometrically at 665 nm as its complex with arsenazo III. Zirconium was separated from binary as well as tertiary mixtures by exploiting the difference in the distribution coefficient or by selective extraction or selective stripping. The method was applied for the analysis of zircon. Zirconium was extracted as its anionic complex with various mineral acids by liquid anion exchanger. The chlorocomplex of zirconium was extracted from 6–10 M hydrochloric acid with trioctylamine1–5, triisooctylamine6 or Aliquat 33657. The sulphotocomplex of zirconium was extracted with Aliquat 33658, Primine JMT9, Alamine 33610. The nitratocomplex was less extensively utilised for the extractive separation of zirconium11, 12. Zirconium was extracted quantitatively from oxalate13, 14 and malonate med...

Electrothermal atomisation atomic-absorption spectrophotometric determination of chromium(VI) in urine by solvent extraction separation with liquid anion exchangers.

An electrothermal atomic-absorption spectrophotometric determination of chromium(VI) in urine samples is described. The separation of these ions from the biological matrix by using high relative molecular mass amines (such as Amberlite LA-1 or LA-2 liquid anion exchangers) is also reported.

Liquid-liquid extractive separation of molybdenum(VI) in malonate solutions with high relative molecular mass amines

Molybdenum can be quantitatively extracted with 0.08 M Amberlite LA-2 in xylene at pH 3.0 from 0.02 M malonic acid, stripped with 0.25 M ammonia solution and determined spectrophotometrically with Tiron at 390 nm. Four other liquid anion exchangers were examined as possible extractants and extraction of molybdenum was found to be quantitative over a limited pH range with two of these. Eight common solvents were tested as diluents; of these, hexane, cyclohexane, benzene and xylene were found to be satisfactory.Molybdenum can be separated from elements that do not form complexes with malonic acid by prior stripping of the extract with water. The metal can be separated from elements forming weak complexes by selective stripping with acids. A novel feature of the method is the separation of molybdenum from multi-component mixtures.The method has been applied to the determination of molybdenum in steel and soil.

Elution and spectrophotometric determination of gold after its separation from non-volatile platinum metals by column extraction chromatography

Mixtures of gold(III) and iridium(IV) were separated by column extraction chromatography on silica treated with a tri-n-octylamine (TOA) salt. A mixture 2.25 M in hydrochloric acid and 5 M in nitric acid was used for elution of iridium. Gold was eluted together with the TOA salt by acetone, and after evaporation of the acetone, the TOA chloroaurate was dissolved in chloroform, converted into TOA bromoaurate and determined spectrophotometrically at 395 nm (ϵ = 3.4 × 10 3 l.mole −1 .cm −1). Beer's law was obeyed over the concentration range 5–67 ppm of gold. The method was found suitable for determination of gold after its separation from other metals by extraction chromatography on supports treated with liquid anion-exchangers.

Paper chromatography of some sulfonated azo-dyes used as metallochromic reagents in liquid-liquid anion exchange systems

Chromatographic behaviour of 11 sulfonated azo-dyes used as metallochromic reagents in chloride systems was investigated by paper extraction chromatography and the moist paper technique. It was found that the affinity of reagents to the cellulose treated with liquid anion exchangers decrease in the following order: Titan Yellow, Stilbazo, Zincon, Eriochrome Black T>Magneson II >SPADNS and Arsenazo I∼Arsenazo III>Thoron. The results suggest that the retention of the reagents in extraction chromatography is caused not only by anion exchange process but also by adsorption phenomena. It was found that in acidic media only the sulfonic groups of the reagents form ion-pairs with alkylammmonium cations.

Direct determination of lead in used engine oils by atomic-absorption spectrophotometry

An improved method has been developed for measuring lead in used lubricating oils. The procedure utilises a mixture of acid and a liquid anion exchanger (Aliquat 336) to dissolve the lead particles in 4-methylpentan-2-one and measurement is made by atomic-absorption spectrophotometry. The method is quantitative in the range 0.1–2.5%m/m and is independent of effects caused by variations in particle size, lead species or oil additives. The method is rapid and has good repeatability.

Simple colorimetric determination of phosphate ion using polyurethane foam loaded with a mixture of liquid anion exchanger of molybdate form and tributyl phosphate.

Polyurethane foam loaded with a mixture of liquid anion exchanger (Amberlite LA-2) of molybdate form and tributyl phosphate collects phosphate ion by immersing it in the sample solution, and is colored blue by reduction. The color intensity of the foam is proportional to the phosphate concentration in the (0.2-2)ppm range in 2ml of the sample water and (0.05-0.5)ppm range in 10ml of the sample water.

Extraction of cobalt(II) and nickel(II) with mixtures of 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one (HPMBP) and tri-n-octylamine (TOA)

The extraction of Co(II) with mixtures of 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one ((H)PMBP) and tri-n-octylamine (TOA) is investigated in order to explore the influence of diluents and inorganic anions with synergistic acidic extractant + liquid anion exchanger systems. Although it is proved that the same species [HTOA]+ [Co(PMBP)3]− is extracted from various inorganic media, with toluene as the diluent, the presence of ClO4− SO42− or Cl− anion modifies the distribution of the anions which are associated to (HTOA)+ in the organic phase, leading to different synergistic equilibria; with Cl− or SO42−: CO(PMBP)2 + (HTOA+,PMBP−) ⇄(HTOA+,Co(PMBP)3− (log K = 6.10) and with ClO4− : Co(PMBP)2 + HPMBP + (HTOA+,ClO4− ⇄ (HTOA+,Co(PMBP)3− + H+ + ClO4− (log K = 2.34) The same synergistic equilibrium is observed for the extraction of Ni(II) from ClO4− medium, with a comparable value of the constant (log K = 2.45). The synergistic effect is cancelled in n-octanol.

Paper chromatography of some chelating reagents containing sulfonic groups in liquid-liquid anion exchange systems

Chromatographic behaviour of nine chelating reagents in chloride and perchlorate systems was investigated with two methods: paper extraction chromatography and moist paper technique. It was found that the affinity of the reagents to cellulose treated with liquid anion exchangers decrease in the following orders: Eriochrome cyanine R>Chromazurol S>Pyrocatechol violet, and Alizarin S>ferron>chromotropic acid ∼ nitroso-R-salt>sulfosalicylic acid>tiron. The results obtained suggest that the retention of reagents in extraction chromatography is caused not only by anion-exchange process but also by adsorption and probably also by partition phenomena. The number of alkylammonium cations forming extracted species with reagents depends on the number of sulfonic groups in the reagent molecule but in sulfosalicylic acid carboxylic group can also be partially bound.

Liquid Anion Exchange Studies and Separation of Mercury

Abstract A new method is developed for the extractive separation of mercury from associated elements. Mercury is quantitatively extracted from 0.5 M acetic acid solution by aliquat 336 S, which acts as a liquid anion exchanger. The metal ion from the organic phase is stripped with sodium hydroxide solution and determined in the aqueous phase complexometrically. The extracted species is [2(R4N+), Hg(OAc)4 −2]. A working procedure for the selective separation of mercury from zinc, cadmium, nickel, cobalt, copper, bismuth and manganese is described.

Enflurane biotransformation in humans

The biotransformation of enflurane was investigated in humans. Liquid anion exchange chromatography of extracts of urine obtained during and following enflurane anesthesia revealed the presence of two organic fluoride containing enflurane metabolites. Gas chromatographic-mass spectroscopic analysis of lyophilized urine extracts indicated the presence of 2-difluoromethoxy- 2,2-difluoro-acetic acid. These results suggest that enflurane undergoes both oxidative dechlorination at the β carbon and O-demethylation at the ether linkage in humans.

Coloured liquid anion-exchangers

Of the several stable and coloured uninegative ions examined, trans-bis(dimethylglyoximato) dinitritocobaltate(III) ([Co(C 4H 7O 2) 2(NO 2) 2] -, termed goldenate ion, G -) can advantageously replace the erdmannate ion in the formation of a more photochemically stable coloured anion-exchanger derived from Aliquat-336 chloride. Quantitative spectrophotometric measurements of its displacement by chloride, bromide and perchlorate ions were made and are discussed together with literature data to examine the effect of parameters such as the nature of the cation and of the anion and change in the organic solvent on the relative and absolute values of extraction constants.

Liquid-liquid extraction of thorium from malonate solution with liquid anion-exchangers

Thorium is quantitatively extracted with 4% Amberlite LA-1 or LA-2 in xylene, from 0.01 M malonic acid medium at pH 3.0 and stripped from the organic phase with 1 M hydrochloric acid, then determined spectrophotometrically at 545 nm as its complex with thoron. It is separated from other elements by selective extraction and stripping.

Extraction chromatography of noble metals with use of mixtures of hydrochloric and nitric acid as mobile phases

The chromatographic behaviour of the platinum metals and gold, silver and copper on paper strips treated with liquid anion-exchangers and eluted with mixtures of HNO 3 and HCl was investigated. It was found that increase of HNO 3 concentration in the acid mixture increases the R F values more significantly than does that of HCl. The presence of HNO 3 in the development solution prevents the reduction of iridium(IV). The R F values of the noble metals increase in the order Au(III) < Os(IV) < Ir(IV) < Pt(IV) < Pd(II) < Ru(III) < Rh(III) ∼ Ir(III). Several separations of noble metals were carried out on paper strips treated with trioctylamine or quaternary alkylammonium salts, as well as the column separation of the mixture PtPdRh. The proposed chromatographic systems seem to be especially useful for the separation of non-volatile noble metals.

Pulsating column separation and preconcentration of radioiodine on hydrophobic organic reagent loaded resilient open-cell polyurethane foam

The method is based on the resiliency of the open-cell polyurethane foam filling used in a pulsing bed column. A liquid anion exchanger containing I2 has been used as a hydrophobic organic phase immobilized in the polyurethane foam matrix. Forced flow of the mobile phase during successive pulsing of the column bed results in high preconcentration factors with practically quantitative separation yields. The pulsated column technique may also be conveniently automated. It can be utilized most advantageously for the rapid determination of low activity radioiodine in environmental waters mainly in routine field analysis.

Isolation of organic anions by extraction with liquid anion exchangers and its application to micromethods for acetylcholinesterase and 4-aminobutyrate aminotransferase.

Organic anions of particular importance to biochemistry such as Krebs cycle intermediates, glycolysis intermediates, simple fatty acids, adenine nucleotides and CoA derivatives can be quantitatively extracted from a buffered solution by high-molecular-weight ammonium salts in an organic solvent. Phosphate salts of tertiary amines in chloroform were the most efficient extractants. The isolation procedure was found to be an example of amine neutralization. The effect of pH, different inorganic anions, volume ratios between the two phases, concentration of the isolated anions and concentration of the ammonium salts have been investigated. The extraction technique has been applied to rapid and sensitive radiochemical methods for the determination of acetylcholinesterase and 4-aminobutyrate aminotransferase activities.

Paper chromatography of noble metals in mixed chloride-nitrate media with use of solutions of liquid anion exchangers as mobile phases

The chromatographic behaviour of nine noble metals on paper strips impregnated with mixtures of HCl and HNO3 and developed with solutions of secondary and tertiary amine salts or quatermary alkylammonium salts in organic diluents was investigated. It was found that very sharp separation of the pair Pt−Pd is obtainable at development of chromatograms with 0.1 Aliquat 336 in xylene or with 0.1 mol dm−3 TOA in kerosene at high concentrations of the acids in the stationary phase. The increase of concentration of HNO3 in acids mixture decreases the RF or RM values for the platinum metals more distinctly than increase of concentration of HCl.

Analytical applications of a liquid anion-exchanger for the separation of uranium(IV) in malonate solution

Uranium was quantitatively extracted with 4% Amberlite LA-1 in xylene at pH 2.5–4.0 from 0.001 M malonic acid. It was stripped from the organic phase with 0.01 M sodium hydroxide and determined spectrophotometrically at 530 nm as its complex with 4-(2-pyridylazo) resorcinol. Of various liquid anion-exchangers tested, Amberlite LA-1 was found to be best. Uranium was separated from alkali and alkaline earth metal ions, thallium(I), iron(II), silver, arsenic(III) and tin(IV) by selective extraction, and from zinc, cadmium, nickel, copper(II), cobalt(II), chromium(III), aluminium, iron(III), lead, bismuth, antimony(III) and yttrium by selective stripping. The separation from scandium, zirconium, thorium and vanadium(V) was done by exploiting differences in the stability of chloro-complexes.

Determination of131I in soil using a liquid anion exchanger and liquid scintillation technique

A simple method for rapid determination of131I in soil is described. The method is based on the specific separation and concentration of radioiodine from the soil extract with a liquid anion exchanger and measuring its radioactivity with liquid scintillation counting. The131I from soil is extracted with aqueous solution of sodium hydroxide. The method permits the determination of131I with a lower limit of detection less than 0.1 Bq/10 g of soil.