Andreas Prange and Dirk Schaumlöffel
The development and analytical characterization of a coupled capillary electrophoresis-inductively coupled plasma sector field mass spectrometer (CE-ICP-SFMS) system for the simultaneous determination of different species of As, Sb, Se and Te at trace levels are described. The species are separated by CE using a 55 cm×75 µm id fused silica capillary column. A newly developed interface with a special, low dead volume spray chamber allows the optimization of the fluid mechanical properties, thus preventing a suction effect between the nebulizer and the CE capillary. The ICP-SFMS instrument runs in the low resolution mode and is equipped with a grounded platinum electrode at the ICP torch in order to achieve the highest possible sensitivity. The CE-ICP-SFMS system developed provides stable electrophoretic conditions and allows reproducible separations to be obtained with RSDs below 3% for the migration times and below 8% for the peak areas. Excellent peak shapes down to 4 s and short analysis times of a few minutes are other important features of this combined instrument. Detection limits in the low µg L–1 region for compounds and in the picogram to femtogram range for the isotopes are achieved from standard solutions.