溫濕度對六種工業用有機溶劑分析方法回收率之影響

Influence of Relative Humidity and Temperature on Analysis Methods of Six Organic Solvents

作業場所之高溫及高溼環境可能會影響環境測定的結果，本研究之目的在探討溫濕度及混存物對有機溶劑分析方法的影響﹐選定六種常見的有機溶劑甲苯﹑二甲苯﹑丙酮﹑甲基異丁酮﹑乙酸乙酯及乙酸丁酯﹐以動態標準氣體產生系統產生不同溫濕條件下的已知濃度（0.5,1,2 倍PEL）混合有機蒸氣﹐以活性碳管進行主動式採樣後進行分析。本研究發現以所選定的六種有機溶劑在本研究所設定的相對濕度40%與80%的狀況下，除丙酮及乙酸乙酯略微受到濕度之影響而降低回收率外，並不會影響分析的結果﹔但在溫度為30℃及20℃時，則可發現較高溫時回收率較佳﹐且具有統計上的意義。但總的來說﹐在本研究所設定的條件下（濃度0.5-2倍PEL﹔溫度30℃及20℃﹔相對濕度40%及80%），此六種有機溶劑的混存物其回收率均大於80%﹐在採樣時除非溫濕條件特別極端其回收率並未受到太大的影響。

Extreme temperature and humidity in workplace can significantly influence the results of environmental monitoring. In this study, dynamic standard gas generation system combined with activated charcoal tubes were used to investigate the temperature and humidity effects of six most widely used industrial solvents including toluene, xylene, acetone, methyl iso-butyl ketone, ethyl acetate at the level of 0.5, 1 and 2 PEL (Permissible Exposure limits). The results showed no significant differences between high (80%) and low (40%) humidity for test solvents except Acetone and Ethyl Acetate, which showed lower recoveries at high humidity. The recoveries rates at high temperature (30 oC) are higher than low temperature (20oC). In general, the recoveries of six mixed solvents in the tested conditions (0.5 / 1 / 2 PEL, 20oC / 30oC, and 40% / 80%) were all greater than 80%. Therefore, under normal working conditions, the temperature and humidity effects are not significant.