Department of Green Chemistry, LUT University, Sammonkatu 12, FI-50130, Mikkeli, Finland; Department of Chemistry and Biochemistry, 1175 North Horseshoe Drive, New Mexico State University, Las Cruces, NM, 88003, USA.
Department of Plant and Environmental Sciences, 1175 North Horseshoe Drive, New Mexico State University, Las Cruces, NM, 88003, USA.
Anal Chim Acta. 2019 Dec 27;1092:144-150. doi: 10.1016/j.aca.2019.09.040. Epub 2019 Sep 17.
Response of an ion mobility spectrometer at ambient pressure was quantitatively determined for fourteen chemicals from five chemical families spanning a range of proton affinities and temperature from 30 to 175 °C with moisture from 1 to 1 × 10 ppm in purified air. Peak intensities, drift times and reduced mobility coefficients were determined for hydrated protons from aNi ion source and for protonated monomers and proton bound dimers of alcohols, aldehydes, acetates, ketones, and organophosphates. These measurements permitted the determination of response factors with atmospheric pressure chemical ionization and the influence of moisture and temperature on APCI response with correlation to computational models of hydration values. The formation of protonated monomers and proton bound dimers was described by heats of formation for a displacement reaction of water on H(HO) by an analyte vapor and favorably matched results from density functional theory (DFT) with the 6-311 + G(dp) basis set. Response factors worsened with increased moisture and decreased temperature for compounds of medium, and more so, of low proton affinities. Findings here provide a broad measure and understanding for quantitative response in ion mobility spectrometers for substances for combinations of moisture and temperature.
在大气压下，对跨越质子亲和力和温度范围从 30 到 175°C 的五个化学家族的 14 种化学物质的离子迁移谱仪的响应进行了定量测定，其中湿度为 1 到 1×10 ppm，在净化空气中。从 Ni 离子源确定了水合质子、醇、醛、乙酸盐、酮和有机磷酸盐的质子化单体和质子结合二聚体的峰强度、漂移时间和还原迁移率系数。这些测量允许确定大气压化学电离的响应因子，并研究水分和温度对 APCI 响应的影响，以及与水合值计算模型的相关性。质子化单体和质子结合二聚体的形成由取代反应的形成热描述，其中水通过分析物蒸汽取代 H(HO)，并与密度泛函理论 (DFT) 的结果很好地匹配，采用 6-311+G(dp)基组。对于中等质子亲和力和较低质子亲和力的化合物，随着水分的增加和温度的降低，响应因子会变差。这里的发现为离子迁移谱仪对水分和温度组合物质的定量响应提供了广泛的衡量和理解。
