Although, steroid profiling is being applied in clinical and biochemical studies, improvement of the technique is still needed for accurate quantification of steroids in case of limited biological sample volumes. To improve analytical sensitivity and selectivity in comparison to that of conventional methods, a method that comprises supported liquid extraction (SLE) and gas chromatography-mass spectrometry with a combination of selected-reaction and selected-ion monitoring modes (GC-SRM/SIM-MS) was developed. Here, this combination of SLE purification with GC-MS method was optimized with 37 different types of steroids and the results were compared to a solid-phase extraction (SPE) method. The devised assay led to an increase in extraction efficiency with the good chromatographic selectivity through a single extraction step. The limits of quantification of the serum steroids, ranged from 0.2 to 5 ng mL-1, except for cholesterol (0.2 μg mL-1), and the correlation coefficients for calibration curves were higher than 0.99. The precision and accuracy were 1.4%-10.5% and 82.7%-115.3%, respectively. The overall recoveries of 30 steroids ranged from 62.1% to 104.3%, while that of 7 sterols was 44.7%-75.7%. Then, this validated method was applied to monitor the serum steroid levels of mice, which showed significant sex and age dependent metabolic patterns. This technique can be used to evaluate the metabolic changes occurring in animal models as well as in clinical patients.

中文翻译：

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支持液体萃取与气相色谱选择性质谱扫描模式相结合，用于血清类固醇分析

尽管类固醇分析已应用于临床和生化研究，但在生物样本量有限的情况下，仍需要改进该技术以准确定量类固醇。与传统方法相比，为了提高分析灵敏度和选择性，该方法包括支持液体萃取 (SLE) 和气相色谱-质谱，结合选择反应和选择离子监测模式 (GC-SRM/SIM- MS) 的开发。在这里，SLE 纯化与 GC-MS 方法的组合使用 37 种不同类型的类固醇进行了优化，并将结果与​​固相萃取 (SPE) 方法进行了比较。设计的分析通过单个提取步骤提高了提取效率，并具有良好的色谱选择性。除胆固醇 (0.2 μg mL-1) 外，血清类固醇的定量限范围为 0.2 至 5 ng mL-1，校准曲线的相关系数高于 0.99。精密度和准确度分别为1.4%-10.5%和82.7%-115.3%。30 种类固醇的总回收率为 62.1% 至 104.3%，而 7 种甾醇的回收率为 44.7%-75.7%。然后，将这种经过验证的方法用于监测小鼠的血清类固醇水平，其表现出显着的性别和年龄依赖性代谢模式。该技术可用于评估动物模型和临床患者中发生的代谢变化。精密度和准确度分别为1.4%-10.5%和82.7%-115.3%。30 种类固醇的总回收率为 62.1% 至 104.3%，而 7 种甾醇的回收率为 44.7%-75.7%。然后，将这种经过验证的方法用于监测小鼠的血清类固醇水平，其表现出显着的性别和年龄依赖性代谢模式。该技术可用于评估动物模型和临床患者中发生的代谢变化。精密度和准确度分别为1.4%-10.5%和82.7%-115.3%。30 种类固醇的总回收率为 62.1% 至 104.3%，而 7 种甾醇的回收率为 44.7%-75.7%。然后，将这种经过验证的方法用于监测小鼠的血清类固醇水平，其表现出显着的性别和年龄依赖性代谢模式。该技术可用于评估动物模型和临床患者中发生的代谢变化。