Abstract Extraction of Dopamine by Homogeneous Liquid –Liquid Extraction method (HLLE) and determination with UV-Vis Spectroscopy

Dopamine (DA), 3,4 dihydroxyphenylethylamine, is a organic chemical substance in the catecholamines and phenylethyleamines group, which plays a number of important physiological roles in the brain and body [1,2]. In this study one of the homogenous liquid-liquid extraction methods, which is cloud point extraction, was used in order to preconcentrate and extract dopamine and amount of dopamine was determined by UV-Vis spectroscopy method. Triton x-114 was chosen as a surfactant due to low water content. The significant parameters to extraction were optimized. Experimental result show that high extraction efficiency can be obtained at the optimized parameters: pH=4 of sample solution;1/5% v/v Triton surfactant; time of equilibration 15 min; equilibration of 40ºC ; time and rate of centrifuge 10 min and 5000 rpm respectively. At the optimum conditions the calibration plot of dopamine was drawn with good linearity (?2≥0.999) and using this plot, figures of merit of the proposed method were investigated. The given method presents suitable working linear ranges (0.05-1, μg. L-1), good limit of detection (0.02 μg.L-1), relative standard deviation (%RSD≤4.7) and good recycle percentage (recovery > 88%). Finally the proposed method was used for two types of real samples.