便携式原子吸收测汞仪对气态汞的监测方法

Research on Gaseous Mercury Monitoring Methods Using a Portable Atomic Absorption Mercury Analyzer

研究和比较便携式原子吸收测汞仪测定气态汞的两种方法,即富集法和直读法。结果显示,富集法在一定范围内具有较好的线性相关性,R2>0.996,当采气体积为12 L时,检出限为5 ng/m^3,对于高浓度和低浓度气态汞的测定均有较好的稳定性,当气态汞浓度较低时可延长取样时间,增加采样体积,但测定时间较长,适合测定环境空气中的低浓度气态汞。直读法的检出限为0.89μg/m^3,且在测定高浓度含汞废气时,表现出较好的稳定性,同时可在持续排放气态汞条件下进行连续测定并读数,适合测定固定污染源排气中的气态汞。

Two methods, i. e. , the enrichment method and the direct-reading method, both of which used a portable atomic absorption mercury analyzer, were studied and compared for monitoring of gaseous mercury. The results showed that the enrichment method had a good linearity within a defined range, with R2 〉 0. 996. The detection limit of gaseous mercury in the air was 5 ng/m3 when the sampling volume was 12 L. The enrichment method showed good stability in determining both high and tow concentrations of gaseous mercury. When the mercury concentration was low, the sampling time and volume could be extended. However, the analytical time became longer. It was appropriate for the determination of gaseous mercury at low level in the ambient air. The detection limit of the direct-reading method was 0. 89 μg/m3, and this method showed better stability in determining high concentrations of mercury in industrial waste gas. The direct-reading method could be used for continuous determination of gaseous mercury in the process of continuous discharge. Therefore, this method was suitable for determining gaseous mercury from stationary pollution sources.