Laboratory validation of a passive sampler for SO2 atmospheric monitoring

Abstract

The performance of a passive sampler was tested under exposure in Teflon chamber. The SO2 trapped in impregnated filter with 1.0 × 10-2 mol L-1 Na2CO3 solution was extracted in ultrasound bath with H2O2 solution for 15 min and determined as SO42- by ion chromatography. The sampler presented good performance except for air in total stillness condition (0 m s-1), for very short exposure periods (0.5 h), for atmosphere with O3 ≥ 150 μg m-3 and for high concentrations of reduced sulfur compounds. The relative humidity of the air (20-80%) and the exposure to zero concentration did not affect the sampler performance. It showed stability for one month at 4°C or for one week at about 25°C. Its precision varied within 3.5 and 23% depending of the SO2 concentration and the accuracy varied from 91 to 100%. ©2005 Sociedade Brasileira de Química.