Catecholoamines in urine: mass screening with microelectrode method.

尿中单胺类物质的测定对神经母细胞瘤和嗜铬细胞瘤的发现有重要意义。在我们最近的研究（临床化学，1982年），我们研究了一种方法，用于测定单胺的人尿中使用高效液相色谱电化学检测。但是，这种方法测定一个样品的单胺需要20分钟以上。最近，我们发展了一种新的技术，使用碳纤维电极在体外测定多巴胺。碳纤维电极与计算机控制的DA/AD系统相连。电极的灵敏度约为10^<-7>- 10^<-8>M。在抗坏血酸和二羟苯乙酸（D@oPAC）存在下，<-7>可检测到试管中10 μ M的多巴胺，虽然我们用这种新技术测定了正常人尿中的多巴胺，但由于电极的灵敏度不够，不能直接测定未经纯化的尿中的多巴胺，中性母细胞瘤病人尿中的多巴胺浓度可能比正常人高10 ~ 100倍。因此，这种新的技术可能适用于鳍片的大规模筛选。

Determinations of monoamines in human urine are very important to find the patients with neuroblastoma or pheochromcytoma. In our recent research ( Clinical Chemistry, 1982), we inverstigated a method for the determination of monoamines is human urine using high-performance liquid chromatography with electrochemical detection. However, this method spend over 20 min to determine the monoamines for one sample.Recently, we developed a new technique using a carbon fiber electrode to determing dopamine in vitro. The catbon fiber electrode is connected with computer-controled DA/AD system. The sensitivity of the electrod is about 10^<-7>- 10^<-8>M. In the presence of ascorbic acid and dihydroxyphenylacetic acid (D@oPAC), 10^<-7>M of dopamine in the test tube could be detected.Although we applied this new technique to determine the concentration of dopamine in normal human urine, the sensitibity of the electrode was not not enough to determing the dopamine in the urine without any purification of it. Concentration of dopamine in the urine of neutoblastoms'a patinets may be 10 - 100 fold higher than that in the normal urine. Therefore, this new rechnique may be applicable to fins the patinets by a mass screening.