Abstract

Gas-phase on-line derivatization in the ion source of a DART mass spectrometer is a new approach to the efficient detection of alcohols in complex matrices. It does not require any special sample handling; it is based just on mixing an alcohol with a nitrogen-containing compound with high proton affinity. The resulting N-alkyl-derivatized cations appear in DART spectra as very characteristic and highly intense signals. In addition to the earlier used pyridine and quinoline, we propose a new reagent, 4-N,N-dimethylaminopyridine (4-DMAP), having a higher proton affinity. It is shown that DART mass spectra recorded for alcohols in the presence of an equimolar mixture of pyridine and 4-DMAP reveal peaks that are mainly due to the 4-DMAP quaternization cation. This indicates a highly competitive ability of this reagent to get protonated and then predominantly participate in ion-molecular reactions with alcohols under study. It is suggested that 4-DMAP provides high sensitivity in the analysis of aliphatic and alicyclic primary and secondary alcohols.

中文翻译：

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“实时直接分析”（DART）质谱仪中的醇离子分子衍生反应：4- N，N-二甲基氨基吡啶作为新型高效试剂

摘要

DART质谱仪离子源中的气相在线衍生化是一种有效检测复杂基质中酒精的新方法。它不需要任何特殊的样品处理；它仅基于将醇与具有高质子亲和力的含氮化合物混合。所得的N-烷基衍生的阳离子在DART光谱中显示为非常特征性和高度强烈的信号。除了较早使用的吡啶和喹啉外，我们还提出了一种新试剂4- N，N-二甲基氨基吡啶（4-DMAP），具有较高的质子亲和力。结果表明，在吡啶和4-DMAP等摩尔混合物的存在下，醇的DART质谱图揭示了主要归因于4-DMAP季铵化阳离子的峰。这表明该试剂具有很高的竞争能力，使其质子化，然后主要参与与所研究醇的离子分子反应。建议4-DMAP在脂肪族和脂环族伯醇和仲醇的分析中具有很高的灵敏度。