CAPILLARY-ELECTROPHORESIS INTERFACED TO INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY FOR ELEMENT-SELECTIVE DETECTION IN ARSENIC SPECIATION

A method is presented to separate and detect six arsenic species by ca pillary electrophoresis (CE) interfaced to inductively coupled plasma mass spectrometry (ICP-MS). CE was used as a highly resolving separati on system, whereas ICP-MS served as an element selective detector prov iding low detection limits. The special mode of operation included sam ple stacking and a differentiation of separation and detection. This p rovided separation and detection of six As species, uncharged and anio nic, to be monitored within a single run. Detection limits were calcul ated according to IUPAC recommendation at 15 mu g As/L for As (III), d imethyl arsinic acid (DA), monomethyl arsonic acid (MA) and As (V), or 65 mu g As/L for arsenobetaine (AsB) and arsenocholine (AsC). Investi gations were focused on possibly occurring interferences, e.g., ArClinterference at the monoisotope As-75. Finally, real samples from biom edical field (urine) and environmental field (sewage sludge) were anal yzed.