Quantitative thin-layer chromatography/mass spectrometry analysis of caffeine using a surface sampling probe electrospray ionization tandem mass spectrometry system
Quantitative thin-layer chromatography/mass spectrometry analysis of caffeine using a surface sampling probe electrospray ionization tandem mass spectrometry system
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DOI：
10.1021/ac050488s
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发表时间：
2005-07-15
影响因子：
7.4
通讯作者：
Van Berkel, GJ
中科院分区：
文献类型：
--
作者：
Ford, MJ;Deibel, MA;Van Berkel, GJ
报道了使用表面采样电喷雾电离系统和串联质谱检测在反相 CS 薄层色谱板上定量测定咖啡因。薄层色谱/电喷雾串联质谱法采用氘标记咖啡因内标和选择反应监测检测。在单次表面扫描实验中，以 44 μm/s 的表面扫描速率需要 35 分钟，对单个板上多达 9 个平行的咖啡因带进行了采样。同时开发了反相 HPLC/UV 咖啡因测定法来评估质谱方法的性能。根据校准曲线统计数据确定的 HPLC/UV 和薄层色谱/电喷雾串联质谱方法的检测限分别为注射 0.20 纳克（0.50 微升）和板上点样 1.0 纳克。两种方法的标准品和实际样品的加标回收率在 97% 到 106% 之间。测量了三种减肥软饮料（健怡可乐、减肥樱桃可乐、减肥百事可乐）和三种减肥运动饮料（减肥涡轮茶、Speed Stack Grape、Speed Stack Fruit Punch）的咖啡因含量。 HPLC/UV 和质谱测定结果基本一致，并且这些值与三种健怡可乐中的两种的引用值一致。对于低糖樱桃可乐和低糖运动饮料，使用这两种方法测定的咖啡因含量始终高于文献值（接近 8% 或更多）。
Quantitative determination of caffeine on reversed-phase CS thin-layer chromatography plates using a surface sampling electrospray ionization system with tandem mass spectrometry detection is reported. The thin-layer chromatography/electrospray tandem mass spectrometry method employed a deuterium-labeled caffeine internal standard and selected reaction monitoring detection. Up to nine parallel caffeine bands on a single plate were sampled in a single surface scanning experiment requiring 35 min at a surface scan rate of 44 mu m/s. A reversed-phase HPLC/UV caffeine assay was developed in parallel to assess the mass spectrometry method performance. Limits of detection for the HPLC/UV and thin-layer chromatography/electrospray tandem mass spectrometry methods determined from the calibration curve statistics were 0.20 ng injected (0.50 mu L) and 1.0 ng spotted on the plate, respectively. Spike recoveries with standards and real samples ranged between 97 and 106% for both methods. The caffeine content of three diet soft drinks (Diet Coke, Diet Cherry Coke, Diet Pepsi) and three diet sport drinks (Diet Turbo Tea, Speed Stack Grape, Speed Stack Fruit Punch) was measured. The HPLC/UV and mass spectrometry determinations were in general agreement, and these values were consistent with the quoted values for two of the three diet colas. In the case of Diet Cherry Coke and the diet sports drinks, the determined caffeine amounts using both methods were consistently higher (by similar to 8% or more) than the literature values.