Speciation of sulfur-containing anions by use of capillary electrophoresis

Abstract

SummaryOptimization of a CE method with indirect UV detection for speciation of suJfur-containing anions is described. Sensitivity, selectivity, and separation using a chromate background electrolyte (the electrolyte most often used for inorganic anions) and a pyromelhtate electrolyte are compared. The pyromellitate electrolyte is recommended because its use results in better sensitivity for the ions analyzed. The composition of the electrolyte was 2.25 mM pyromellitic acid, 6.5 mM NaOH, 0.75 mM hexamethonium hydroxide, and 1.6 mM triethanolamine, pH 10. Separation of seven sulfur-containing anions with indirect detection at 254 nm was achieved in one run in less than 7 min.

The Importance of Thiosalts Speciation: Review of Analytical Methods, Kinetics, and Treatment

“…Haddad (1997) presented the first study comparing results between ion chromatography (IC) and capillary electrophoresis (CE) for thiosalts. Further studies (Motellier and Descostes, 2001;Padarauskas et al, 2000;Poboży et al, 2002) explored the advantages of the CE and developed methods for the different species, which are presented in Section 2.…”

Capillary electrophoresis of inorganic ions: An update

“…8) [107,119] and neptunium oxidation states [107]. Much research continues on improving speciation measurements in real-world samples, with advanced CE procedures tailor-made to the analysis of natural [94,95,156,157,160,161,168,173,187,249,250] and waste waters [79,94,95], soil solutions or extracts [78,104], air [253], minerals [245], industrial samples and technological solutions [83,189,190,198,233,235,236,254,256], pharmaceutical preparations [199,248,255], biological material [102,118,175,231,251,252], food [224], and animal feed [211], etc. In particular, an innovative methodology for the automatic monitoring of mercury species in aquatic samples was suggested by Valcárcel's group [237].…”

Overview of the status and applications of capillary electrophoresis to the analysis of small molecules

“…Various important aspects of speciation, such as sample pretreatment, metal ion complexation, detection, detection limit, choice of electrolytes were described for an number of examples. Speciation of anions is also possible, for example speciation of sulphur containing anions has been reported [50]. Detection was achieved by the addition of pyromellitate ion into the pH 10 electrolyte.…”