The new ionization technique termed vibrating sharp-edge spray ionization (cVSSI) has been coupled with corona discharge to investigate atmospheric pressure chemical ionization (APCI) capabilities. The optimized source was evaluated for its ability to enhance ion signal intensity, overcome matrix effects, and limit ion suppression. The results have been compared with state-of-the-art ESI source performance as well as a new APCI-like source. In methanol, the ion signal intensity increased 10-fold and >10-fold for cocaine and the suppressed analytes, respectively. The ability to overcome ion suppression was improved from 2-fold to 16-fold for theophylline and vitamin D2, respectively. For aqueous samples, ion signal levels increased by two orders of magnitude for all analytes. In both solvent systems, the signal-to-noise ratios also increased for all suppressed analytes. One example of the characterization of low-ionizing (by ESI or cVSSI alone) species in the presence of high-ionizing species by direct analysis from a cotton swab is presented. The work is discussed with respect to the advantages of cVSSI-APCI for direct, in situ, and field analyses.

中文翻译：

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开发 cVSSI-APCI 以改善复杂混合物中的离子抑制和基质效应

称为振动锐边喷雾电离 (cVSSI) 的新型电离技术与电晕放电相结合，可研究大气压化学电离 (APCI) 的能力。评估了优化源增强离子信号强度、克服基质效应和限制离子抑制的能力。结果已与最先进的 ESI 源性能以及新的类似 APCI 源进行了比较。在甲醇中，可卡因和抑制分析物的离子信号强度分别增加 10 倍和 >10 倍。茶碱和维生素 D2 克服离子抑制的能力分别从 2 倍提高到 16 倍。对于水性样品，所有分析物的离子信号水平增加了两个数量级。在两种溶剂体系中，所有抑制分析物的信噪比也有所增加。介绍了通过棉签直接分析在高电离物质存在的情况下表征低电离物质（仅通过 ESI 或 cVSSI）的一个示例。这项工作讨论了 cVSSI-APCI 在直接、原位和现场分析方面的优势。