Gas phase reaction of trace iodine-129 for determination by ICP-DRC-MS/MS

Matsueda, Makoto   ; Aoki, Jo; Koarai, Kazuma   ; Terashima, Motoki  ; Takagai, Yoshitaka*

Long half-life I have provided important information as a tracer to estimate the environmental behaviour of radioisotopes released from nuclear facilities. Inductively coupled plasma-mass spectrometry (ICP-MS) is capable of rapid data acquisition, but the application is limited caused by the main interferences at m/z 129 (IH and Xe). It has been reported that Xe can be removed by introducing O gas into the reaction cell in an ICP-MS. Tandem mass spectrometry (ICP-MS/MS) has also made it possible to suppress the formation of IH. However, more precise removal of interferences is required to apply various environmental samples. In this study, the gas-phase reactions between I and interferents were investigated in a reaction cell of an ICP-MS/MS. The results showed that introducing an O-CO gas mixture into the reaction cell reduced the background counts of m/z 129 to a minimum level.