Treatment Of Dopamine Like Biological Samples And Establishment Of Electrochemical Detection Methods

Catecholamine is a biological nerve neurotransmitter which is composed of two hydroxy benzene ring and anamino chain. Dopamine (DA) belongs to catecholamine, which has an important physiological significance to the neural regulation of the human body and the related series of activities. Alzheimer’s disease, epilepsy and Parkinson disease is caused by abnormal DA content in the human body. Therefore, the study of DA is of great significance for the protection of human health. And L-dopais a very important kind of catecholamine as DA. It is the precursors of DA synthesis, which can be through the blood brain barrier into the brain tissue and is a good supplement, thus achieving the treatment of Parkinson.It is promising for the use of two kinds of catecholamine substances, so it is necessary to establish a simple, rapid and accurate method for the detection of dopamine and L-dopa..Because DA and L-dopa have special electrochemical activities,the detection and measurement of them can be carried out by electrochemical method. However, the main problem comes from the AA interference in the electrochemical determination of the experiment. In the human body fluid and brain, the concentration of AA is much higher than the concentration of dopamine and L-dopa,and their redox potentialsare similar. Therefore, how to eliminate the interference of AA, reducing the detection limit of dopamine and L-dopaare the most important thing in the electrochemical analysis.In this experiment, the electrochemical signal of AA decreased significantly during the negative potential scanning, while the electrochemical signal of dopamine and L-dopaare essentially unchanged. Optimal conditions were obtained by selecting pH, static time, scanning width, frequency and so on. In the optimal conditions, the method can be performed to detect the trace DA and L-dopa in the presence of AA. When the mixed solution was determined by differential pulse method, the linear relationship between the peak current and the concentration of DA was in the range of 2.0x 10-7～1.0×10-5mol/L. Detection limit has reached 1.0×10-7mol/L. It was applied to measure DA in human urine. The concentration of L-dopa in the range of 1.0× 10-6～5.0÷10-4mol/L has a good linear relationship with the peak current. Detection limit has reached 1.0×10-7mol/L.