作業環境汞蒸氣分析技術研發

Analytical Method Development for Measurement of Workplace Mercury Vapor

本研究以SnCl2取代原先勞工委員會2308建議分析方中之NaBH4還原劑，利用冷汞蒸氣產生器配合原子吸收光譜法，測定作業環境空氣中汞蒸氣濃度。研究中以2 L/min氬氣流量與約2 mL 5%SnCl2/10%HNO3溶液進行冷汞蒸氣之產生，同時偵測253.7 nm波長汞原子吸收波峰積分面積，以定量樣品中汞之含量。分析檢量線標準樣品以1% HNO3配製，在濃度範圍為2至80 ng/mL間檢量線線性相關係數（r值）為0.9999，其偵測極限為0.015μg/sample。在汞蒸氣採樣常用之Hoplicate與Hydrar採樣介質，添加相當於0.5、1及2倍容許暴露濃度（PEL）之汞樣品中，平均回收率分別為101.6 %與102.2 %；而分析變異係數分別為1.20 %與1.18 %。

An analytical method for environmental monitoring of mercury vapor at workplace was developed by cold vapor atomic absorption spectrometry, where SnCl2 was used in place of NaBH4 as reductant in the generation of mercury cold vapor. In this study, argon gas was applied to the cold vapor generator at 2 L/min to deliver 2 mL reducing solution (5 % SnCl2 / 10 % HNO3) to the reaction flask where Hg2+ was reduced to Hg vapor. The detection of mercury atomic absorption was performed at 253.7 nm. The absorbance peak area was used in the quantitaion of mercury vapor. Calibration standards at concentration between 2 and 80 ng/mL were prepared by dilution of 1000μg/mL of stock solution with 1 % HNO3 . the coefficient of correlation (r) of calibration curve was 0.9999 and the detection limit was 0.015μg/sample. The mean values of recoveries in Hoplicate and Hydrar sampling media spiked with 0.5, 1 and 2 PEL levels of concentrations were 101.6 % and 102.2 %, and the analytical coefficient of variance (CVa) were 1.20 % and 1.18 %, respectively.