van de Merbel Nico C, Hendriks Gert, Imbos Roos, Tuunainen Johanna, Rouru Juha, Nikkanen Hanna
Bioanalytical Laboratory, PRA International, Westerbrink 3, 9405 BJ Assen, The Netherlands.
Bioanalysis. 2011 Sep;3(17):1949-61. doi: 10.4155/bio.11.170.
Two methods have been developed and validated for the determination of free and total dopamine in human plasma. They are based on solid-phase extraction of the analyte from the matrix by covalent complexation with phenylboronic acid, followed by derivatization with ethylchloroformate. The derivative is quantified by reversed-phase liquid chromatography on a C18 column and positive electrospray ionization MS/MS.
The high selectivity obtained, in combination with the stable and relatively non-polar nature of the derivatized analyte, enables the reliable quantification of dopamine in the range 0.05 to 20 ng/ml in a 5 min run time, using only 100 µl of sample. Total dopamine concentrations are determined (range 1 to 400 ng/ml) by including an acidic hydrolysis step, which converts the sulphate and glucuronide conjugates to free dopamine prior to extraction. The method was applied to quantify free and total dopamine levels in human plasma after dosing with the anti-Parkinson's drug combination L-dopa/carbidopa with and without entacapone.
A sensitive and selective LC-MS/MS method has been developed and validated for the determination of free and total dopamine in human plasma. This article demonstrates how essential careful optimization of the sample preparation procedures was for developing a successful method.
已开发并验证了两种用于测定人血浆中游离多巴胺和总多巴胺的方法。它们基于通过与苯硼酸共价络合从基质中固相萃取分析物，然后用氯甲酸乙酯衍生化。衍生物通过在C18柱上的反相液相色谱和正电喷雾电离质谱/质谱进行定量。
所获得的高选择性，结合衍生化分析物稳定且相对非极性的性质，使得仅使用100μl样品就能在5分钟的运行时间内可靠地定量0.05至20 ng/ml范围内的多巴胺。通过包括酸性水解步骤来测定总多巴胺浓度（范围为1至400 ng/ml），该步骤在萃取前将硫酸盐和葡糖醛酸共轭物转化为游离多巴胺。该方法应用于定量服用抗帕金森病药物组合左旋多巴/卡比多巴（有无恩他卡朋）后人血浆中游离和总多巴胺水平。
已开发并验证了一种灵敏且选择性的液相色谱-质谱/质谱法用于测定人血浆中游离和总多巴胺。本文展示了样品制备程序的仔细优化对于开发成功方法是多么重要。
