Capillary electrophoretic and micellar electrokinetic separations of asymmetric dimethyl-L-arginine and structurally related amino acids: Quantitation in human plasma
Capillary electrophoretic and micellar electrokinetic separations of asymmetric dimethyl-L-arginine and structurally related amino acids: Quantitation in human plasma
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DOI：
10.1002/jssc.200401918
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发表时间：
2004-12-01
影响因子：
3.1
通讯作者：
Zare, RN
中科院分区：
文献类型：
--
作者：
Trapp, G;Sydow, K;Zare, RN
我们报告的发展有效的电泳方法的分离和定量的L-精氨酸和六个天然存在的衍生物，结构和功能相关。采用pH 9.4的浓硼酸盐缓冲液的毛细管电泳（CE）实现了含有二甲基-L-精氨酸、N-G-单甲基-L-精氨酸、L-精氨酸、L-高精氨酸、L-鸟氨酸和L-精氨酸、瓜氨酸作为4-氟-7-硝基苯并呋咱衍生物的混合物的分离。此外，通过胶束电动色谱（MEKC）的基线分辨率时，高浓度的脱氧胆酸作为表面活性剂添加到相同的运行缓冲液的异构体的二甲基-L-精氨酸衍生物（对称和不对称）的分离。研究了缓冲液种类、浓度、pH值对分离的影响，优化了分离条件。在CE分离中使用UV吸收测定水溶液中不对称二甲基-L-精氨酸的定量限（LOQ）为20 μ M，在MEKC分离中使用激光诱导荧光（LIF）检测测定为0.1 μ M。这种新开发的方法已成功地应用于定量的不对称二甲基-L-精氨酸和L-精氨酸在人血浆样品中的水平，可用作心血管疾病的临床诊断（0.125 μ M LOQ）。
We report the development of efficient electrophoretic methods for the separation and quantification of L-arginine and six naturally occurring derivatives that are structurally and functionally related. Capillary electrophoresis (CE) employing a concentrated borate buffer at pH 9.4 achieves the separation of mixtures containing dimethyl-L-arginine, N-G-monomethyl-L-arginine, L-arginine, L-homoarginine, L-ornithine, and L-arginine, citrulline as 4-fluoro-7-nitrobenzofurazan derivatives. In addition, the separation of the isomeric dimethyl-L-arginine derivatives (symmetric and asymmetric) is attained with baseline resolution by micellar electrokinetic chromatography (MEKC) when a high concentration of deoxycholic acid is added as a surfactant to the same running buffer. The influence of buffer type, concentration, and pH on the separation was studied to optimize separation conditions. The limit of quantitation (LOQ) for asymmetric dimethyl-L-arginine in aqueous solution was determined to be 20 muM using UV absorption in a CE separation and 0.1 muM using laser induced fluorescence (LIF) detection in an MEKC separation. This newly developed method was successfully applied for the quantitation of asymmetric dimethyl-L-arginine and L-arginine in human plasma samples at levels that might be used as a clinical diagnostic for cardiovascular disease (0.125 muM LOQ).