The determination of arsenic(III) and arsenic(V), as inorganic arsenite and arsenate, was
investigated by CE with capacitively coupled contactless conductivity detection (CE-C4D). It was found
necessary to determine the two inorganic arsenic species separately employing two different electrolyte
systems. Electrolyte solutions consisting of 50 mM CAPS/2 mM L-arginine (Arg) (pH 9.0) and of 45 mM
acetic acid (pH 3.2) were used for arsenic(III) and arsenic(V) determinations, respectively. Detection limits
of 0.29 and 0.15 ?M were achieved for As(III) and As(V), respectively by using large-volume injection to
maximize the sensitivity. The analysis of contaminated well water samples from Vietnam is demonstrated.
?? 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
