DEVELOPMENT OF A MEMBRANE INLET MASS-SPECTROMETRIC METHOD FOR ANALYSIS OF AIR SAMPLES

A sheet membrane inlet mass spectrometric (MIMS) method for the on-lin e analysis of volatile organic compounds (VOCs) in air at low mu g/m(3 ) levels was developed. The effects of the thickness of the membrane, the temperature of the membrane inlet and the flow rate of the sample on the responses and response times of some selected VOCs were studied in detail. Under optimised conditions the detection limits for the VO Cs studied were 0.5 - 4 g m(-3) and linear dynamic ranges were about f our orders of magnitude. Response times of only a few seconds were rec orded with a thin (25 mu m) membrane. The developed MIMS method was ap plied to an analysis of air samples from an exhaust of a paintshop, wh ere Volatile organic solvents were used.