Amirkhani Ardeshir, Heldin Eva, Markides Karin E, Bergquist Jonas
Institute of Chemistry, Department of Analytical Chemistry, Uppsala University, PO Box 531, SE-75121 Uppsala, Sweden.
J Chromatogr B Analyt Technol Biomed Life Sci. 2002 Nov 25;780(2):381-7. doi: 10.1016/s1570-0232(02)00572-x.
Concentrations of tryptophan and its metabolites in plasma are of great interest in determining proper diagnosis and medication of several neurological diseases like, for example, Alzheimer's disease. A method of standard addition was developed to determine total level of tryptophan and two of its metabolites, kynurenine and kynurenic acid, in human plasma by capillary liquid chromatography-electrospray ionization tandem mass spectrometry. Plasma samples were simply deproteinized by addition of diluted perchloric acid. Samples were then mixed with trichloroacetic acid and injected onto a capillary column. Analytes were separated by a fast gradient elution of the injected samples. Detection was performed by sheathless electrospray tandem mass spectrometry in the multiple reaction monitoring mode. Linear calibration curves were obtained for spiked plasma sample with up to 100% of the expected analytes concentrations. The determined concentrations were well within ranges previously reported (i.e., 6 nM-95 microM) and limit of detections were around 3 nM for each analyte.
血浆中色氨酸及其代谢物的浓度对于确定几种神经疾病（如阿尔茨海默病）的正确诊断和用药具有重要意义。开发了一种标准加入法，通过毛细管液相色谱 - 电喷雾电离串联质谱法测定人血浆中色氨酸及其两种代谢物犬尿氨酸和犬尿酸的总水平。血浆样品只需加入稀释的高氯酸进行脱蛋白处理。然后将样品与三氯乙酸混合并注入毛细管柱。通过对注入样品的快速梯度洗脱分离分析物。采用无鞘电喷雾串联质谱在多反应监测模式下进行检测。对于加标血浆样品，在预期分析物浓度高达100%的情况下获得了线性校准曲线。所测定的浓度完全在先前报道的范围内（即6 nM - 95 μM），每种分析物的检测限约为3 nM。
