Analytical Sciences


Abstract − Analytical Sciences, 18(3), 293 (2002).

Application of Dopamine as an Electroactive Ligand for the Determination of Aluminum in Biological Fluids
Fuping ZHANG,* Shuping BI,*  Jian LIU,* Xiaodi YANG,* Xianlong WANG,* Li YANG,* Tsing YU,* Yijun CHEN,** Lemei DAI,** and Tianming YANG**,***
*State Key Laboratory of Coordination Chemistry of China, Department of Chemistry, Nanjing University, Nanjing, 210093, China
**Modern Analytical Center, Nanjing University, Nanjing, 210093, China
***Zhongda Subordinative Hospital of South East University, Nanjing, 210024, China
Dopamine (3,4-dihydroxyphenylethylamine, DA) is applied as an electroactive chelant for indirect determination of aluminum (Al) in biological fluids. It is observed that the decrease of the differential pulse voltammetric (DPV) anodic peak current of DA is linear with the increase of Al concentration. Under optimum experimental conditions (pH 8.6, 2.0 x 10-4 M DA, and 0.03 M NH4Ac-NH3·H2O buffer solution), two linear ranges, 5.0 x 10-8 - 4.0 x 10-7 M and 4.0 x 10-7 - 7.2 x 10-6 M AlIII, are obtained. The detection limit of Al is 1.9 x 10-8 M and the relative standard deviation for 4 x 10-6 M AlIII is 3.1% (N = 8). Many biologically active foreign species have been selected for interference. Excellent recoveries and accuracy have been obtained in the measurements of Al in biological samples such as synthetic renal dialysate, Ringer's solution, human whole blood, cerebrospinal fluid of demented patient, and urine of diabetic patient. The methodological principle that Al complexes with DA on the electroactive position result in the depression of electrochemical activities of DA has been verified by comparing both the electrochemical behaviors and the spectroscopic responses like UV-vis and Raman of DA in the presence and in the absence of Al.