Analytical Sensitivity Dependence on Chemical Species of Arsenic Compounds in Atomic Spectrometry

There is a possibility that all accuracy determination of arsenic is difficult ill the case of some existing kinds of chemical compounds in environmental samples due to a sensitivity difference depending on the chemical Compounds. To discuss the phenomenon and the sensitivity difference between chemical compounds, the mechanism and behavior of a sensitivity difference between arsenic Compounds with inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) and more instruments were investigated. The calibration Solutions of As(III) and As(V) were gravimetrically prepared from a unique mother standard Solution of a JCSS As standard Solution, which is certified by Japan Calibration Service System (JCSS). The arsenobetaine was prepared from the certified reference material of a BCR 626 arsenobetaine solution, which is certified by IRMM. In the case of ICP-MS and ICP-OES analyses, internal standard elements were added, and they were monitored together with arsenic. Although there was no sensitivity difference between As(III) and As(V) with atomic absorption spectrometry (AAS), graphite furnace atomic absorption spectrometry (GFAAS), X-ray fluorescence (XRF), and neutron activation analysis (NAA), the As (V) was found to be 4% more sensitive than the As (III) with ICP-MS and ICP-OES. Also, it was concluded that the mechanisms of this sensitivity difference between them were investigated by ICP-MS and ICP-OES, and it was elucidated that the formation rates of hydride polyatomic species of As were definitively different between As(III) and As(V) species in the plasma.