Arsenic speciation exchange columns

There have been few elemental speciation studies in the literature involving cation-exchange chromatography (CEC) coupled to ICP-MS. A cation-exchange column was used by Larsen et al. [57,69] for arsenic speciation in several seafood sample extracts. The chromatography was optimized for the separation of arsenocholine, trimethylarsinic, trimethylarsine oxide, inorganic As, and two unknown cationic arsenic compounds. A mobile phase of 20 mM pyridinium ion, at pH 2.65, was used to perform the separation (Fig. 10.10). 

Wine is a very complex matrix and the accurate, selective determination of species constitutes a challenge for analytical chemists. Furthermore, the speciation analysis of metals bound to biological ligands is a subject of increasing interest since complexation may reduce their toxicity and bioavailability. There is a limited number of studies concerning the speciation analysis of metals or metalloids in wines. Arsenite, arsenate, MMA, and DMA were separated in less than 10 min by means of an anion-exchange column [88], Arsenic species detection was accomplished by the direct coupling of the column effluent to an HG system and AFS was used for detection. LoDs in white wine were 0.16, 0.33, 0.32, and 0.57 ng ml-1 for As(III), DMA, MMA, and As(V), respectively. In real samples... 

Recently, IC has also foimd increased application in the field of metal speciation. Short anion exchange columns have been used for the rapid separation of anionic species of arsenic, selenium, and chromium. 

Common elements speciated using liquid chromatography (LC) coupled with ICP-MS include arsenic, selenium, mercury, antimony in mostly urine samples. Arsenic speciation is usually achieved using an anion-exchange column. Selenium compounds may be separated under conditions similar to those for arsenic, or by a reverse phase column with ion pairing... 

A. Woller, H. Garraud, J. Boisson, A. M. Dorthe, P. Fodor and O. F. X. Donard, Simultaneuous speciation of redox species of arsenic and selenium using an anion-exchange microbore column coupled with a micro-concentric nebuliser and an inductively coupled plasma mass spectrometer as detector, J. Anal. At. Spectrom., 13, 1998, 141-149. 

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