Zhang Hua, Bibi Aisha, Lu Haiyan, Han Jing, Chen Huanwen
Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, No. 418 Guanglan Road, Nanchang, 330013, China.
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, No. 2699 Qianjin Avenue, Changchun, 130012, China.
J Mass Spectrom. 2017 Aug;52(8):526-533. doi: 10.1002/jms.3961.
It is of sustainable interest to improve the sensitivity and selectivity of the ionization process, especially for direct analysis of complex samples without matrix separation. Herein, four ambient ionization methods including desorption atmospheric pressure chemical ionization (DAPCI), heat-assisted desorption atmospheric pressure chemical ionization (heat-assisted DAPCI), microwave plasma torch (MPT) and internal extractive electrospray ionization (iEESI) were employed for comparative analysis of the navel orange tissue samples by mass spectrometry. The volatile organic compounds (e.g. ethanol, vanillin, leaf alcohol and jasmine lactone) were successfully detected by non-heat-assisted DAPCI-MS, while semi-volatile organic compounds (e.g. 1-nonanol and ethyl nonanoate) together with low abundance of non-volatile organic compounds (e.g. sinensetin and nobiletin) were obtained by heat-assisted DAPCI-MS. Typical nonvolatile organic compounds [e.g. 5-(hydroxymethyl)furfural and glucosan] were sensitively detected with MPT-MS. Compounds of high polarity (e.g. amino acids, alkaloids and sugars) were easily profiled with iEESI-MS. Our data showed that more analytes could be detected when more energy was delivered for the desorption ionization purpose; however, heat-sensitive analytes would not be detected once the energy input exceeded the dissociation barriers of the analytes. For the later cases, soft ionization methods such as iEESI were recommended to sensitively profile the bioanalytes of high polarity. Copyright © 2017 John Wiley & Sons, Ltd.
提高电离过程的灵敏度和选择性一直具有可持续的研究价值，特别是对于无需基质分离即可直接分析复杂样品而言。在此，采用了四种常压电离方法，包括解吸大气压化学电离（DAPCI）、热辅助解吸大气压化学电离（热辅助DAPCI）、微波等离子体炬（MPT）和内部萃取电喷雾电离（iEESI），通过质谱对脐橙组织样品进行对比分析。挥发性有机化合物（如乙醇、香草醛、叶醇和茉莉内酯）通过非热辅助DAPCI-MS成功检测到，而半挥发性有机化合物（如1-壬醇和壬酸乙酯）以及低丰度的非挥发性有机化合物（如川陈皮素和诺米林）则通过热辅助DAPCI-MS获得。典型的非挥发性有机化合物[如5-（羟甲基）糠醛和葡聚糖]通过MPT-MS被灵敏地检测到。高极性化合物（如氨基酸、生物碱和糖类）通过iEESI-MS很容易被分析。我们的数据表明，为了解吸电离目的提供更多能量时，可以检测到更多的分析物；然而，一旦能量输入超过分析物的解离屏障，热敏性分析物将无法被检测到。对于后一种情况，建议使用iEESI等软电离方法来灵敏地分析高极性生物分析物。版权所有© 2017约翰威立父子有限公司。
