Nemeškalová Alžběta, Konvalinková Jitka, Vágnerová Magdaléna, Kuchař Martin, Buček Jan, Vrkoslav Vladimír, Sýkora David, Cvačka Josef, Volny Michael
Department of Analytical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Czech Republic.
Department of Analytical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Czech Republic; Forensic Laboratory of Biologically Active Substances, Department of Chemistry of Natural Compounds, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Czech Republic.
Talanta. 2024 Sep 1;277:126358. doi: 10.1016/j.talanta.2024.126358. Epub 2024 Jun 6.
Ambient ionization mass spectrometry allows for analysis of samples in their natural state, i.e., with no sample pre-treatment. It can be viewed as a fast, simple, and economical analysis, but its main disadvantages include a lower analytical performance due to the presence of complex sample matrix and the lack of chromatographic separation prior to the introduction of the sample into the mass spectrometer. Here we present an application of two ambient ionization mass spectrometry techniques, i.e., Desorption Atmospheric Pressure Photoionization and Dielectric Barrier Discharge Ionization, for the analysis of known Selective Androgen Receptor Modulators, which represent common compounds of abuse in professional and semiprofessional sport. Eight real samples of illegal food supplements, seized by the local law enforcement, were used to test the performance of the ambient mass spectrometry and the results were validated against a newly developed targeted LC-UV-MS/MS method performed in multiple reaction monitoring mode with an external calibration for each analyte. In order to decide whether or not the compound can be declared as present, we proposed a system of rules for the interpretation of the obtained spectra. The criteria are based on mass spectrum matching (5-10 ppm accuracy from the theoretical exact mass and a correct isotopic pattern), duration of the mass signal (three or five consecutive scans, depending on the instrumentation used), and intensity above the background noise (threefold increase in intensity and absolute intensity above 5E4 or 1E5, depending on the instrumentation). When applying these criteria, good agreement was found between the tested methods. Ambient ionization techniques were effective at detecting SARMs at pharmacologically relevant doses, i.e., approximately above 1 mg per capsule, although they may fail to detect lower levels or isomeric species. It is demonstrated that when adhering to a set of clear and consistent rules, ambient mass spectrometry can be employed as a qualitative technique for the screening of illegal SARMs with sufficient confidence and without the necessity to perform a regular LC-MS analysis.
常压电离质谱法可对天然状态的样品进行分析，即无需样品预处理。它可被视为一种快速、简便且经济的分析方法，但其主要缺点包括：由于存在复杂的样品基质，分析性能较低，且在将样品引入质谱仪之前缺乏色谱分离。在此，我们展示了两种常压电离质谱技术，即解吸常压光电离和介质阻挡放电电离，在分析已知选择性雄激素受体调节剂方面的应用，这些调节剂是职业和半职业体育中常见的滥用化合物。使用当地执法部门查获的八个非法食品补充剂实际样品来测试常压质谱的性能，并将结果与新开发的靶向液相色谱 - 紫外 - 串联质谱法进行验证，该方法在多反应监测模式下对每种分析物进行外部校准。为了确定化合物是否可被宣布存在，我们提出了一套用于解释所得光谱的规则系统。这些标准基于质谱匹配（与理论精确质量的准确度为5 - 10 ppm，且同位素模式正确）、质量信号的持续时间（根据所用仪器，连续扫描三次或五次）以及高于背景噪声的强度（强度增加三倍且绝对强度高于5E4或1E5，取决于所用仪器）。应用这些标准时，发现测试方法之间具有良好的一致性。常压电离技术在检测药理相关剂量的选择性雄激素受体调节剂方面是有效的，即每粒胶囊约1毫克以上，尽管它们可能无法检测到较低水平或异构体。结果表明，当遵循一套清晰一致的规则时，常压质谱可作为一种定性技术，以足够的置信度筛选非法选择性雄激素受体调节剂，而无需进行常规的液相色谱 - 质谱分析。
