Development Of A High Concentration Method Using Modified GP-MSE For Determination Of Trace Semivolatile Organic Pollutants In Gaseous Phase Of Atmosphere

Semivolatile organic pollutants in gaseous phase of atmosphere are trace to ultra trace level, but they can also though a direct contact or indirect ways seriously threaten to human health because of their toxicity and bioaccumulation. A large number sample was needed in analysis of trace organic pollutants in gaseous phase of atmosphere to reach the instrument limit using the conventional concentration techniques. It is costly, energy-demanding and time-consuming. A sensitive concentration method utilizing modified gas purge microsyringe extraction (GP-MSE) has been developed. Concentration (reduction in volume) to micro liter quantity has been achieved which improved the sensitivity and it has the advantage of simple, fast and environmental friendly. PAHs representing the semivolatile analytes have been utilized to optimize the various parameters that affect the concentration efficiency. Injection rate and temperature were the key factors that influence the concentration efficiency. An efficient concentration (75.0-96.1%) of PAHs was obtained under the best optimized conditions:80℃,167μL min-1of injection rate and2.0mL min-1of gas flow rate. It revealed good reproducibility (RSD values ranged from1.5to9.0%). GP-MSE concentration method enhances volume reduction (concentration factor) leading to low method detection limit (0.5-15ng L-1). The concentration factor of GP-MSE was much higher than the conventional evaporation concentration techniques and the concentration factor increased by two orders of magnitude which greatly reduced the initial sampling volume. Utilizing this method in combination with GC-MS, diurnal hourly flux of PAHs from gaseous phase of atmosphere has been measured.