Amad M H, Cech N B, Jackson G S, Enke C G
Department of Chemistry, University of New Mexico, Albuquerque 87131-1096, USA.
J Mass Spectrom. 2000 Jul;35(7):784-9. doi: 10.1002/1096-9888(200007)35:7<784::AID-JMS17>3.0.CO;2-Q.
The effect of gas-phase proton transfer reactions on the mass spectral response of solvents and analytes with known gas-phase proton affinities was evaluated. Methanol, ethanol, propanol and water mixtures were employed to probe the effect of gas-phase proton transfer reactions on the abundance of protonated solvent ions. Ion-molecule reactions were carried out either in an atmospheric pressure electrospray ionization source or in the central quadrupole of a triple-quadrupole mass spectrometer. The introduction of solvent vapor with higher gas-phase proton affinity than the solvent being electrosprayed caused protons to transfer to the gas-phase solvent molecules. In mixed solvents, protonated solvent clusters of the solvent with higher gas-phase proton affinity dominated the resulting mass spectra. The effect of solvent gas-phase proton affinity on analyte response was also investigated, and the analyte response was suppressed or eliminated in solvents with gas-phase proton affinities higher than that of the analyte.
评估了气相质子转移反应对具有已知气相质子亲和力的溶剂和分析物质谱响应的影响。使用甲醇、乙醇、丙醇和水的混合物来探究气相质子转移反应对质子化溶剂离子丰度的影响。离子 - 分子反应在大气压电喷雾电离源中或在三重四极杆质谱仪的中心四极杆中进行。引入气相质子亲和力高于正在进行电喷雾的溶剂的溶剂蒸汽会导致质子转移到气相溶剂分子上。在混合溶剂中，具有较高气相质子亲和力的溶剂的质子化溶剂簇主导了所得质谱。还研究了溶剂气相质子亲和力对分析物响应的影响，并且在气相质子亲和力高于分析物的溶剂中，分析物响应被抑制或消除。
