| Summary: | 碩士 === 國立臺灣大學 === 化學研究所 === 87 === The apparatus of flow-injection analysis (FIA) coupled inductively coupled plasma mass spectrometry is used to determine lead contents in organic solvent. FIA provides the advantages of matrix separation and analyte preconcentration. The lead is retained as a Pb-DDPA complex on a microcolumn packed with a C18 bonded silica, and methanol is then used as an eluent. A multi-tube Nafion membrane dryer is installed between the ultrasonic nebulizer and torch of a plasma source as a part of desolvation system. The membrane can further remove about 50% (w/w) of methanol after leaving the ultrasonic nebulizer, such that the torch may be not quenched. In addition, for minimizing the interference caused, the eluent is confined to a small volume before introducing into torch. When sample is loaded in the microcolumn for 15 and 60s, respectively, detection limits ( 3σ) for lead are determined to be 0.162 and 0.028 ppt, enrichment factor are 6.9 and 27.8, and the sampling frequencies are 31 and 21 h-1. The sample consumption is also reduced to 0.75 and 3 ml for 15 and 60s sample loading. The method is successfully applied to determine the trace lead seawater NASS-4.
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