GC Determination of Pyridine in Waste Gas with Absorption Liquid Sampling and Headspace

Absorption liquid was used as collection of the waste gas sample. After headspace sampling, GC was applied to the determination of pyridine in the sampling gas. The analyte was separated on DB-FFAP capillary chromatographic column and detected by hydrogen flame ionization detector. The optimized conditions found were as follows:1 porous glass plate absorption bottle was used for sample collection; 2 volume of absorption solution was 45 mL; 3 sampling flow was 0.5 L·min^-1; 4 the sample was analyzed within 7 days at 4℃; 5 pH of absorption solution was more than 12; 6 3 g sodium chloride was added to adjust the ionic strength of absorption solution; 7 the temperature and equilibrium time of headspace were set at 80℃ and 30min. Linear relationship between values of peak area and mass concentration of pyridine was kept in the range within 100 mg·L^-1, with detection limit of 0.05 mg·m^-3. Three standard gases of pyridine with different concentration levels were determined, giving relative errors in the range of -8.0%—-4.7% with RSDs (n=6) of determination values in the range of 1.3%-7.8%.