ENHANCED SELECTIVITY IN ION MOBILITY SPECTROMETRY ANALYSIS OF COMPLEX-MIXTURES BY ALTERNATE REAGENT GAS CHEMISTRY
ENHANCED SELECTIVITY IN ION MOBILITY SPECTROMETRY ANALYSIS OF COMPLEX-MIXTURES BY ALTERNATE REAGENT GAS CHEMISTRY
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DOI：
10.1016/0003-2670(94)00668-c
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发表时间：
1995-04-28
影响因子：
6.2
通讯作者：
SHOFF, DB
中科院分区：
文献类型：
--
作者：
EICEMAN, GA;WANG, YF;SHOFF, DB
离子迁移谱法（IMS）对挥发性有机化合物（VOCs）和有机磷化合物（OPCs）在10-40 mg/m(3)蒸汽水平下的复杂混合物进行分析，产生了具有宽剖面的迁移谱，说明了离子迁移谱法（IMS）用于筛选此类混合物的局限性。通过气相色谱仪入口与离子迁移谱仪进行预分离，提高了OPC的分析选择性，但OPC的检测因与其他VOCs共洗脱而变得复杂。离子迁移谱仪离子源中的水试剂气体在45种VOCs和19种OPCs的混合物中产生46个气相色谱峰。两种物质共洗脱的色谱峰有8个，三种物质共洗脱的色谱峰有4个。在离子源中使用质子亲和性提高的试剂气体，获得了进一步的选择性。丙酮和二甲亚砜的试剂气相化学分别减少了26个和20个GC峰。此外，这些试剂气体在50至1000 pg水平下保留了OPCs的光谱完整性和定量响应。对于OPCs，在这些分析条件下，分析物离子显示为M(2)H（+）型，产物离子的迁移率与试剂气体无关。使用表征良好的OPC离子作为参考，将降低的迁移率值分配给OPC光谱。光谱分布和降低的迁移率表明，OPC产物离子在100℃时不与试剂气体分子聚集。
Ion mobility spectrometry (IMS) analysis of a complex mixture of volatile organic compounds (VOCs) and organophosphorus compounds (OPCs) at vapor levels of 10-40 mg/m(3) produced mobility spectra with broad profiles illustrating limitations of ion mobility spectrometry (IMS) for screening such mixtures. Preseparation of this mixture with a gas chromatograph inlet to an ion mobility spectrometer enhanced analytical selectivity although OPC detection was complicated by co-elution with other VOCs. Water reagent gas in the ion source of the ion mobility spectrometer yielded 46 gas chromatographic peaks in a mixture of 45 VOCs and 19 OPCs. Co-elution of two materials was observed in eight of the chromatographic peaks and co-elution of three materials occurred in four instances. Further selectivity was gained using reagent gases of elevated proton affinity in the ion source. Reagent gas chemistry for acetone and dimethylsulfoxide reduced the number of GC peaks to 26 and 20, respectively. Moreover, spectral integrity and quantitative response for OPCs were retained at 50 to 1000 pg levels with these reagent gases. For OPCs, analyte ions were shown to be of the type M(2)H(+) under these conditions of analysis and the mobilities of the product ions were independent of reagent gas. Reduced mobility values were assigned to OPC spectra using a well-characterized OPC ion as the reference. Spectral profiles and reduced mobilities suggested that the OPC product ions were not clustered with reagent gas molecules at 100 degrees C.