Determination of arsenic and selenium by hydride generation atomic absorption spectrometry using a gas-liquid separator and a dehydration trap

Hydride generated in a mixing coil was collected in a gas-liquid separator, dehydrated in a dehydration trap, and swept into an electrically heated furnace by manipulating electromagnetic relays and timers. Interferences From transition metals were eliminated by the Chelex 100 separation. Sharp peaks were recorded on a recorder. Detection limits (signal to noise ratio 3) of arsenic and selenium were 0.6 ng/ml and 1 ng/ml, respectively. Accuracies checked with biological standard reference materials obtained from the National Institute of Standards and Technology (NIST) of USA and the National Research Council (NRC) of Canada were within the certified values except for those Of oyster tissue. (C) 1996 Academic Press, Inc.