Kågedal B, Pettersson A
Clin Chem. 1983 Dec;29(12):2031-4.
A phenylboronate affinity gel has been investigated for use in the prepurification of urine before "high-performance" liquid chromatography and electrochemical determination of 5-S-L-cysteinyl-L-dopa. At pH 5.6 this naturally occurring 5-S-cysteinyldopa was adsorbed on a phenylboronate column and was quantitatively eluted with trichloroacetate, pH 3.0. This pretreatment of urine before "high-performance" liquid chromatography produced satisfactory chromatographic separations, and the results were further improved when the purification procedure also included treatment on a cation exchanger. By using 5-S-D-cysteinyl-L-dopa--a diastereomer to 5-S-L-cysteinyl-L-dopa--as an internal standard, we have developed a practical routine method for the quantitative determination of urinary 5-S-L-cysteinyl-L-dopa. The precision (CV = 2.4%) and analytical recovery (96.9%, SD 5.3%) were satisfactory and the results obtained correlated well with a previously described method.
一种苯基硼酸亲和凝胶已被研究用于在“高效”液相色谱法和5-S-L-半胱氨酰-L-多巴的电化学测定之前对尿液进行预纯化。在pH 5.6时，这种天然存在的5-S-半胱氨酰多巴被吸附在苯基硼酸柱上，并用pH 3.0的三氯乙酸定量洗脱。在“高效”液相色谱法之前对尿液进行这种预处理可产生令人满意的色谱分离，并且当纯化程序还包括在阳离子交换剂上进行处理时，结果会进一步改善。通过使用5-S-D-半胱氨酰-L-多巴（5-S-L-半胱氨酰-L-多巴的非对映异构体）作为内标，我们开发了一种实用的常规方法来定量测定尿中的5-S-L-半胱氨酰-L-多巴。精密度（CV = 2.4%）和分析回收率（96.9%，SD 5.3%）令人满意，并且所获得的结果与先前描述的方法相关性良好。
