甲苯蒸氣被動式採樣器評估之研究

Evaluation on Airborne Toluene Passive Samplers

本研究探討在臺灣高溫、高濕環境下被動式採樣器集甲苯蒸氣之準確性。在測試條件為30度C，80%RH下，將六個被動式採樣器和六根活性碳管同時採集動態的甲苯氣體，測試濃度為20和200ppm，被動式採樣腔內氣體速為0.5m/sec，採樣時間為30~240分；計測試四種不同廠牌的被動式採樣器，每個廠牌各測試四至六回。結果顯示被動式採樣器所得之濃度相對於活性碳管採樣法之偏差約為5%，另被動式和主動式測定值之變異係數各約為3.0%和3.8%，且以添加法所得之脫附效率均大於95%。此外在油漆塗料廠和大型石化工廠現場採樣結果顯示此四種廠牌和主動式所得之差異則擴大，其平均約為30%。研究結果顯示，若小心使用則甲苯蒸氣被動式採樣方法可作為主動採樣方法的輔助，以方便勞工和採樣者的使用，而不致影響結果致鉅；但當採樣濃渡恰好在法定容許濃度附近時，則宜以主動式採樣方法再確認之。

In order to investigate the sampling accuracy for organic solvents under warm and humid environment, toluene was utilized as a target compound to evaluate the perfornace of commercially available passive samplers (PS). The testing manifold consisted of dynamic standard gas generation system, a passive sampling chamber and an active sampling chamber. Both chambers had 6-8 sampling ports for sitting sampling media. The challenge condition wad 30℃, 80% relative humidity and flow rate in the passive sampling chamber was 0.5m/sec. The toluene testing concentration were 20 and 200 ppm, and the sampling time ranged from 30 to 240 min fous brands of PS. Were test. Each was tested for 4 to 6 rounds, which had 6 samples as well as 6 active samples. As compared to the active sampling concentrations, the PM had average bias about 5%. Results indicated that the coefficent of variation for the passive method was 3.0% and that of active method was 3.8%. In addition, the recovery rates of spiked PS were greater than 95%. For further field validation, study was carried out in several petrochemical and paint manufacturing factories. However, bias did increase to approximately 25% as compared to the active method. With careful operation, passive sampling method might be a resource to the active sampling method for the convenience of workers and field hygienists, and not to affect the results significantly. When monitoring results are near the permissible exposure limit, active sampling method is highly recommended to double check the exposure.