A sensitive method for atmospheric sulfur dioxide determination by reaction cell inductively coupled plasma mass spectrometer.

A sensitive method for sulfur dioxide (SO2) determination was developed with reaction cell inductively coupled plasma mass spectrometer (ICP-MS) by preconcentrating SO2 from gas samples to solutions. O2 flow rate was set at 0.7 ml min-1 for optimal signal to noise ratio at m/z 48 (32S16O+). Favourable conditions to prepare SO2 concentrated solutions including sampling flow rate, the volume of concentrated solution, the number of perfluoroalkoxy alkane (PFA) bubble absorption bottles and the composition of concentrated solution were investigated using SO2 in nitrogen gas reference materials within the range of 5.00 parts per billion (ppb) to 1.00 parts per million (ppm). A limit of detection (LOD) of 0.11 ppb was achieved, corresponding to 100 l 5.00 ppb SO2 with a sampling flow rate of 0.5 l min-1. This method also showed favourable selectivity in the assay of atmosphere SO2 level, providing its promising further application in monitoring gaseous environmental pollutants.