Separation of arsenic species by capillary electrophoresis with sample-stacking techniques.
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.
Chen
Zu Liang
ZL
Adelaide Laboratory, CSIRO Land and Water, PMB2, 5064 Glen Osmond, SA, Australia. zuliang.chen@csiro.au
Lin
Jin-Ming
JM
Naidu
Ravendra
R
D001151:Arsenic / Q000737:chemistry / Q000302:isolation & purification*; D019075:Electrophoresis, Capillary / Q000379:methods*; D012680:Sensitivity and Specificity
D001151:Arsenic