title: Separation of arsenic species by capillary electrophoresis with sample-stacking techniques.
abstract: A simple capillary zone electrophoresis procedure was developed for the separation of arsenic species (AsO(2)(2-), AsO(4)(2-), and dimethylarsinic acid, DMA). Both counter-electroosmotic and co-electroosmotic (EOF) modes were investigated for the separation of arsenic species with direct UV detection at 185 nm using 20 mmol L(-1) sodium phosphate as the electrolyte. The separation selectivity mainly depends on the separation modes and electrolyte pH. Inorganic anions (Cl(-), NO(2)(-), NO(3)(-) and SO(4)(2-)) presented in real samples did not interfere with arsenic speciation in either separation mode. To improve the detection limits, sample-stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were investigated for the preconcentration of As species in co-CZE mode. Less than 1 micromol L(-1) of detection limits for As species were achieved using FASI. The proposed method was demonstrated for the separation and detection of As species in water.
authors.affiliation: Adelaide Laboratory, CSIRO Land and Water, PMB2, 5064 Glen Osmond, SA, Australia. zuliang.chen@csiro.au
authors.forename: Zu Liang
authors.initials: ZL
authors.lastname: Chen
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
authors.forename: Ravendra
authors.initials: R
authors.lastname: Naidu
mesh_terms: D001151:Arsenic / Q000737:chemistry / Q000302:isolation & purification*; D019075:Electrophoresis, Capillary / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D001151:Arsenic