Field instrument for simultaneous large dynamic range measurement of atmospheric hydrogen sulfide, methanethiol, and sulfur dioxide.
Field instrument for simultaneous large dynamic range measurement of atmospheric hydrogen sulfide, methanethiol, and sulfur dioxide.
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DOI：
10.1021/es034450d
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发表时间：
2004-03
影响因子：
11.4
通讯作者：
K. Toda;S. Ohira;Takayoshi Tanaka;T. Nishimura;P. Dasgupta
中科院分区：
文献类型：
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作者：
K. Toda;S. Ohira;Takayoshi Tanaka;T. Nishimura;P. Dasgupta
我们描述了一种基于膜的收集/分析系统，差分监测H2S和CH 3SH，并使用相同的收集器耦合到电导SO2分析仪。由Nafion管组成的扩散洗涤器（DS）选择性地收集H2S，而多孔聚四氟乙烯（pPTFE）DS收集H2S和CH 3SH。这两种气体都是通过它们与荧光素醋酸汞（FMA）反应的能力来测量的，这会导致荧光减弱。通过使用由短洗涤器和长洗涤器组成的双DS单元，连续放置在液体流动管线中，克服了负信号程序的有限动态范围。研究了不同的DS设计和膜材料。H2S，CH 3SH，和SO2从生物源点源进行了连续测量，和H2S/CH 3SH数据比较以及与标准程序，涉及Tedlar袋收集，预浓缩和热脱附从Tenax陷阱，并通过气相色谱/火焰光度检测测量。该仪器的便携性和H2S和SO2的大动态范围测量在Mt.阿索火山。
We describe a membrane-based collection/analysis system that differentially monitors H2S and CH3SH, and to which a conductometric SO2 analyzer using the same collector was coupled. A diffusion scrubber (DS) comprised of a Nafion tube collects H2S selectively while a porous polytetrafluoroethylene (pPTFE) DS collects both H2S and CH3SH. Both gases are measured via their ability to react with fluorescein mercuric acetate (FMA) which results in decreased fluorescence. The limited dynamic range of a negative signal procedure was overcome by using dual DS units comprised of short and long scrubbers, placed serially in the liquid flow line. Different DS designs and membrane materials were investigated. H2S, CH3SH, and SO2 from a biogenic point source were continuously measured, and the H2S/CH3SH data compared well with a standard procedure involving Tedlar bag collection, preconcentration and thermal desorption from a Tenax trap, and measurement by gas chromatography/flame photometric detection. Walkaround portability of the instrument and very large dynamic range measurement of H2S and SO2 were demonstrated around the Mt. Aso volcano.