Institute of Chemistry, University of Tartu , Ravila 14a, 50411, Tartu, Estonia.
Univ Lyon, CNRS, Université Claude Bernard Lyon 1, Ens de Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, F-69100, Villeurbanne, France.
Anal Chem. 2017 Jun 6;89(11):5665-5668. doi: 10.1021/acs.analchem.7b00096. Epub 2017 May 18.
For the first time, the electrospray ionization efficiency (IE) scales in positive and negative mode are united into a single system enabling direct comparison of IE values across ionization modes. This is made possible by the use of a reference compound that ionizes to a similar extent in both positive and negative modes. Thus, choosing the optimal (i.e., most sensitive) ionization conditions for a given set of analytes is enabled. Ionization efficiencies of 33 compounds ionizing in both modes demonstrate that, contrary to general practice, negative mode allows better sensitivity for 46% of such compounds whereas the positive mode is preferred for only 18%, and for 36%, the results for both modes are comparable.
首次将正、负离子模式的电喷雾电离效率（IE）归一化为单一体系，实现了两种模式IE 值的直接比较。通过使用在正、负离子模式下均能达到相似程度电离的参考化合物，实现了这一点。因此，可以为给定的一组分析物选择最佳（即最灵敏）的电离条件。对 33 种在两种模式下均能电离的化合物的电离效率进行研究，结果表明，与常规做法相反，对于 46%的此类化合物，负离子模式的灵敏度更高，而正离子模式仅为 18%，对于 36%的化合物，两种模式的结果相当。
