Unconjugated sex steroids in human serum play a crucial role in physiological and pathological studies and are frequently considered as biomarkers in clinical diagnosis. Because of their low polarity, poor volatility, and low concentration, the rapid and highly sensitive analysis of sex steroids in real serum matrix by ambient mass spectrometry is still challenging. Here, Leidenfrost effect-assisted thermal desorption atmospheric pressure photoionization orbitrap mass spectrometry (LETD-APPI-MS) was developed and applied to quantify free sex steroids in human serum without derivatization and chromatography separation within a few minutes. The concentration of target analyte could be increased by approximately two orders during the LETD process. The limit of quantifications and detections of endogenous sex steroids in human serum were measured at the ppt level. In contrast with commonly used immunoassays in clinical laboratories, LETD-APPI-MS enables the accurate measurements of multiple free sex steroids without the interference of cross-reactions. The endogenous sex steroids of 38 female serums at four physiological stages during pregnancy were rapidly tested by LETD-APPI-MS, whose results were highly consistent with that using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS), indicating LETD-APPI-MS has a strong clinical application potential in steroid analysis.

中文翻译：

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使用莱顿弗罗斯特效应辅助热解吸大气压光电离轨道阱质谱法快速定量人血清中的内源性类固醇

人血清中的非结合性类固醇在生理和病理学研究中起着至关重要的作用，并且经常被认为是临床诊断中的生物标志物。由于它们的极性低、挥发性差和浓度低，通过环境质谱法对真实血清基质中的性类固醇进行快速和高灵敏度的分析仍然具有挑战性。在这里，莱顿弗罗斯特效应辅助热解吸大气压光电离轨道阱质谱 (LETD-APPI-MS) 被开发并应用于在几分钟内量化人血清中的游离性类固醇，而无需衍生化和色谱分离。在 LETD 过程中，目标分析物的浓度可以增加大约两个数量级。人血清中内源性类固醇的定量和检测限在ppt水平上进行了测量。与临床实验室常用的免疫分析相比，LETD-APPI-MS 能够准确测量多种游离性类固醇，而不会干扰交叉反应。采用 LETD-APPI-MS 快速检测妊娠 4 个生理阶段的 38 例女性血清中的内源性激素，结果与液相色谱-大气压化学电离质谱 (LC-APCI-MS) 的结果高度一致，表明LETD-APPI-MS 在类固醇分析中具有很强的临床应用潜力。LETD-APPI-MS 能够准确测量多种游离性类固醇，而不会干扰交叉反应。采用 LETD-APPI-MS 快速检测妊娠 4 个生理阶段的 38 例女性血清中的内源性激素，结果与液相色谱-大气压化学电离质谱 (LC-APCI-MS) 的结果高度一致，表明LETD-APPI-MS 在类固醇分析中具有很强的临床应用潜力。LETD-APPI-MS 能够准确测量多种游离性类固醇，而不会干扰交叉反应。采用 LETD-APPI-MS 快速检测妊娠 4 个生理阶段的 38 例女性血清中的内源性激素，结果与液相色谱-大气压化学电离质谱 (LC-APCI-MS) 的结果高度一致，表明LETD-APPI-MS 在类固醇分析中具有很强的临床应用潜力。