Separation of arsenic

S. Mazan, G. Cretier, N. Gilon, J.-M. Mermet, and J.-L. Rocca, Porous Graphitic Carbon as Stationary Phase for LC-ICPMS Separation of Arsenic Compounds. Anal. Chem. 2002, 74, 1281. For another robust stationary phase, see C. J. Dunlap, C. V. McNeff, D. Stoll, and P. W. Carr, Zirconia Stationary Phases for Extreme Separations, Anal. Chem. 2001, 73, 599A. 

The distillation separation procedure was the principal method used for the arsenic determinations, but more recently Santoliquido (24) has developed a method for the carrier-free separation of arsenic from low-temperature coal ash involving retention on an inorganic exchanger column. 

The crystals dissolve in carbon disulphide and ebullioscopic measurements indicate1 that the molecular formula is As2I4 they also dissolve in ether, alcohol and chloroform. When exposed to air, these solutions darken in colour owing to the formation of the triiodide, and the diiodide cannot be recovered bv evaporation owing to complete decomposition. Boiling acetic anhydride also dissolves the crystals but, on cooling, a yellow substance which appears to contain a derivative of the triiodide separates. The diiodide is also decomposed by pyridine with separation of arsenic, the triiodide being found in solution. 

Ghimire, K.N., Inoue, K., Yamaguchi, H. et al. (2003) Adsorptive separation of arsenate and arsenite anions from aqueous medium by using orange waste. Water Research, 37(20), 4945-53. 

Gecol, H., Ergican, E. and Fuchs, A. (2004) Molecular level separation of arsenic (V) from water using cationic surfactant micelles and ultrafiltration membrane. Journal of Membrane Science, 241(1), 105-19. 

Naidu et al. [9] showed that the separation of arsenic species from soil solutions could be performed in less than five minutes by using capillary electrophoresis. Levels of arsenic down to 0.1-0.5ng/l can be detected. 

Separation of arsenic(III) and dimethylarsinic acid by elution with sodium hydrogen carbonate was satisfactory in the pH range 5.2-6.0. Elution of monomethylarsonic acid was accelerated and satisfactory separation from arsenic(V) achieved using saturated aqueous carbon dioxide (pH4.0-4.2) containing lOg L 1 of ammonium chloride. In order to avoid oxidation of trivalent to pentavalent arsenic on the column, it was necessary to pretreat the resin with 1M nitric acid and 0.1M EDTA before use. 

Chen, Z.L., Lin, J.-M., Naidu, R. Separation of arsenic species by capillary electrophoresis with sample-stacking techniques. Anal. Bioanal. Chem. 375, 679-684 (2003)... 

Low column recovery can also be caused by an excessively large surface area of the stationary phase in relation to the quantity of analyte, which is a common tendency in trace analysis. For example, the recovery of arsenic in the separation of arsenic(V) acid, its methylated derivatives MMA, DMA, trimethylarsine oxide (TMAO), and arsenic(lll) acid was 101-104 % in extracts from frog tissue in which arsenic was found at the milligram per kilogram level, and only 20 % in extracts from fish tissue containing arsenic in nanogram per kilogram amounts [169]. 

Latva, S., Hurtta, M., Peraniemi, S., Ahlgren, M. Separation of arsenic species in aqueous solutions and optimization of determination by graphite furnace atomic absorption spectrometry. Anal. Chim. Acta 418, 11-17 (2000)... 

Yoshida, I., Ueno, K. and Kobayashi, H., Selective separation of arsenic (III) and (V) ions with ferric complex of chelating ion-exchange resin, Sep. Sci. 13, 173-184 (1978). 

FIGURE 28. Separation of arsenic(III) and dimethylarsinic acid on SRA70 by elution with carbon dioxide-hydrogen carbon as a function of pH 1, arsenic(III) 2, dimethylarsinic acid. Reproduced from Reference 210 by permission of The Royal Society of Chemistry... 

B H3mier, C. Sutton, K.L. Caruso, J.A. A comparison of four nebulizer/spray chamber interfaces for the high performance liquid chromatographic separation of arsenic compounds using ICP-MS detection. J. Anal. At. Spectrom. 1998, 13, 855-858. 

Fig. 8-15. Separation of arsenate in an aqueous extract from fly ash. - Chromatographic conditions see Fig. 8-13 injection 50 pL sample (undiluted).

Mazan, S., Cretier, G., Gilon, N., Mermet, J. M., Rocca, J. L. Porous graphitic carbon as stationary phase for LC-ICPMS separation of arsenic compounds in water. Anal Chem 2002, 74, 1281-1287. Bissen, M., Frimmel, F. H. Speciation of As(III), As(V), MMA and DMA in contaminated soil extracts by HPLC-ICP/MS. Fresenius J Anal Chem 2000, 367, 51-55. 

Wangkam, S., Pergantis, S. A. High-speed separation of arsenic compounds using narrow-bore high-performance liquid chromatography on-line with inductively coupled plasma mass spectrometry. J Anal At Spectrom 2000, 15, 627-633. 

Figure 6.23. Anion-exchangc separation of arsenic species. A 5.0 mM ammonium carbonatc/5.0 mM ammonium bicarbonate eluent was used at 80 pL7min flow rate and a 10 pL sample volume. Peaks (in order) As(III), MMA, As(V) (from Ref. [27] with permission).

Tam GKH, Charbonneau SM, Brice F and Lacroix G (1978) Separation of arsenic metabolites in dog plasma and urine following intravenous injection of As. Anal Biochem 86 505-511. 

The advantages of this method for treating antimony ore are — (1) The separation of arsenic frOm antimony, due to the fact that arsenic oxide is more volatile than antimony trioxide. 

Walker, Qualitative Separation of Arsenic, Antimony, and Tin, Joum. 

Anion-exchange chromatography with a 30 mM sodium phosphate buffer solution at pH 6 was used for the separation of arsenous acid, DMA, MA, and arsenic acid on the polymer-based Hamilton PRP-XlOO anion-exchange column... 

A set of guidelines for the separation of arsenic compounds using ion-exchange chromatography and ICP-MS as element-specific detector has been published (58). 

S Londesborough, J Mattusch, R Wennrich. Separation of arsenic species by HPLC-ICP-MS. Eresenius J Anal Chem 363 577-581, 1999. 

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