Non-Aqueous Spray Solvents and Solubility Effects in Desorption Electrospray Ionization
Non-Aqueous Spray Solvents and Solubility Effects in Desorption Electrospray Ionization
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DOI：
10.1016/j.jasms.2009.12.012
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发表时间：
2010-04-01
影响因子：
3.2
通讯作者：
Cooks, R. Graham
中科院分区：
文献类型：
--
作者：
Badu-Tawiah, Abraham;Bland, Celine;Cooks, R. Graham
以氯仿、四氢呋喃和乙腈的二元混合物为喷雾溶剂，分析了43种化合物，探讨了非水溶剂在解吸电喷雾电离质谱仪(DESI-MS)中的应用。将氯仿/四氢呋喃(1：1)和氯仿/乙腈(1：1)喷雾溶剂与标准水基喷雾溶剂(甲醇/水，1：1)的数据进行比较，表明非水体系对DESI，特别是在疏水化合物的分析中具有实用价值。非水喷雾溶剂被用来电离温度计分子(苄基吡啶盐)，并显示出较低的内能(与甲醇/水相比，1：1)，这一结果与已知的电喷雾电离中的溶剂效应相似，并可用溶剂对表面张力的影响来解释。根据DESI结果考虑43种分析物的辛醇/水分配系数(K-ow)，揭示了分析物在喷雾溶剂中的溶解度对产生高质量质谱图的重要性。这一发现为DESI机理的液滴拾取描述提供了额外的支持，该描述基于分析物在喷雾溶剂中的溶解，随后到达液膜中的液滴飞溅形成溶解的分析物的微滴。通过使用分析物的K-ow来指示最合适的溶剂体系的极性，可以改进DESI溶剂的优化。(J am Soc MS Spectrm 2010，21,572-579)(C)2010美国质谱学学会
The use of non-aqueous solvents in desorption electrospray ionization mass spectrometry (DESI-MS) is explored by analyzing a set of 43 compounds using binary mixtures of chloroform, tetrahydrofuran, and acetonitrile as the spray solvent. Comparisons of data obtained from chloroform/tetrahydrofuran (1:1) and chloroform/acetonitrile (1:1) spray solvents with the standard aqueous-based spray solvent (methanol/water, 1:1) shows that the non-aqueous systems have practical value for DESI, especially in the analysis of hydrophobic compounds. Non-aqueous spray solvents were used to ionize thermometer molecules (benzyl pyridinium salts) and showed lower internal energies (softer DESI ionization compared with methanol/water, 1:1), a result that has parallels in known solvent effects in electrospray ionization and is explained by solvent effects on surface tension. Consideration of octanol/water partition coefficients (K-ow) of the 43 analytes in the light of their DESI results reveals the importance of the solubility of analyte in the spray solvent in producing high quality mass spectra. This finding provides additional support for the droplet pick-up description of the DESI mechanism, which is based on analyte dissolution in the spray solvent, followed by splashing of subsequently arriving droplets in the liquid film to form microdroplets of dissolved analyte. DESI solvent optimization can be improved by the use of K-ow of the analyte as an indication of the polarity of the most appropriate solvent system. (J Am Soc Mass Spectrom 2010, 21, 572-579) (C) 2010 American Society for Mass Spectrometry