Kågedal B, Pettersson A
J Chromatogr. 1983 Feb 11;272(2):287-97. doi: 10.1016/s0378-4347(00)86131-9.
A high-performance ion-pair liquid chromatographic method with electrochemical detection is described, which is suitable for routine determination of urinary 5-S-cysteinyldopa. The clean-up procedure includes a first purification step on the cation exchanger AG 50 W (H +). After desorption from the resin at moderately raised pH the catecholic amino acid is adsorbed on alumina at pH 8.6, washed and finally desorbed by elution with perchloric acid. By the combined clean-up procedures, easily oxidized compounds are eliminated, which otherwise cause a number of interfering peaks in the chromatography. The synthesis of 5-S-cysteinyl-L-3,4-dihydroxyphenyl [2,3-3H]alanine is described, and this tritium-labelled 5-S-cysteinyldopa is used to determine the recovery in the sample. The precision (C.V. = 5.7% at low and C.V. = 4.9% at high 5-S-cysteinyldopa concentration) and recovery (105.0 +/- 8.6%) were satisfactory. The mean urinary excretion was 0.34 +/- 0.13 (S.D.) mumol per 24 h (range 0.02-0.58 mumol per 24 h) in healthy subjects (n = 24) and in patients with melanoma metastates (n = 13) the excretion ranged from 0.9 to 4.8 mumol per 24 h.
本文描述了一种采用电化学检测的高效离子对液相色谱法，该方法适用于尿中5-S-半胱氨酰多巴的常规测定。净化程序包括在阳离子交换剂AG 50 W（H+）上进行的第一步纯化。在适度升高的pH值下从树脂上解吸后，儿茶酚胺类氨基酸在pH 8.6时吸附在氧化铝上，洗涤后最终用高氯酸洗脱解吸。通过联合净化程序，可消除易氧化的化合物，否则这些化合物会在色谱图中产生许多干扰峰。描述了5-S-半胱氨酰-L-3,4-二羟基苯基[2,3-3H]丙氨酸的合成，并用这种氚标记的5-S-半胱氨酰多巴来测定样品中的回收率。精密度（低浓度时变异系数 = 5.7%，高浓度时变异系数 = 4.9%）和回收率（105.0 +/- 8.6%）令人满意。健康受试者（n = 24）每24小时的平均尿排泄量为0.34 +/- 0.13（标准差）μmol（范围为每24小时0.02 - 0.58 μmol），黑色素瘤转移患者（n = 13）的排泄量范围为每24小时0.9至4.8 μmol。
