Direct Analysis in Real Time Coupled to Multiplexed Drift Tube Ion Mobility Spectrometry for Detecting Toxic Chemicals
Direct Analysis in Real Time Coupled to Multiplexed Drift Tube Ion Mobility Spectrometry for Detecting Toxic Chemicals
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DOI：
10.1021/ac102246h
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发表时间：
2011-03-15
影响因子：
7.4
通讯作者：
Fernandez, Facundo M.
中科院分区：
文献类型：
--
作者：
Harris, Glenn A.;Kwasnik, Mark;Fernandez, Facundo M.
当前和未来对国土安全的化学威胁促使人们需要新的化学探测系统来提供边境、运输和工作场所的安全。我们提出了第一个成功的耦合的商业直接分析在真实的时间（DART）离子源的电阻玻璃单片漂移管离子迁移谱仪（DTIMS）的基础上，低维护，多功能，和强大的化学监测系统。在仪器的电场梯度内的原位电离增强了灵敏度并提供了安全的取样策略。该仪器使用氮气作为DART放电和DTIMS漂移气体，允许高电场用于离子分离，同时保持低使用成本。使用传统的信号平均采集模式，从熔点毛细管取样的分析物的95%检测概率（POD）为DMMP 11.81%v/v，2-CEES 1.13%v/v，甲胺磷10.61 mM。通过原型传输模式几何界面提高了灵敏度，导致DMMP（0.28% v/v）的POD水平降低了近2个数量级。作为一种替代的传输模式操作的DTIMS离子注入步骤的数字复用也实施，发现一个3倍的改善，信噪比为200 μ s的门注入和4.5倍的400 μ s的门注入。
Current and future chemical threats to homeland security motivate the need for new chemical detection systems to provide border, transportation, and workplace security. We present the first successful coupling of a commercial direct analysis in real time (DART) ion source to a resistive glass monolithic drift tube ion mobility spectrometer (DTIMS) as the basis for a low maintenance, versatile, and robust chemical monitoring system. in situ ionization within the electric field gradient of the instrument enhances sensitivity and provides a safe sampling strategy. The instrument uses nitrogen as both the DART discharge and DTIMS drift gases, allowing for a high electric field to be used for ion separation while keeping cost-of-use low. With the use of a traditional signal averaging acquisition mode, the 95% probability of detection (POD) for analytes sampled from melting point capillary tubes was 11.81% v/v for DMMP, 1.13% v/v for 2-CEES, and 10.61 mM for methamidophos. Sensitivity was improved via a prototype transmission mode geometry interface, resulting in an almost 2 orders of magnitude decrease in the POD level for DMMP (0.28% v/v). As an alternative to transmission mode operation digital multiplexing of the DTIMS ion injection step was also implemented, finding a 3-fold improvement in signal-to-noise ratios for 200 mu s gate injections and a 4.5-fold for 400 mu s gate injections.