Analytical Sciences

Abstract − Analytical Sciences, 19(4), 575 (2003).

Electrochemiluminescent Determination of L-Cysteine with a Flow-Injection Analysis System
Liande ZHU, Yingxiu LI, and Guoyi ZHU 
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry,Chinese Academy of Sciences, Changchun 130022, P. R. China
A flow-injection electrochemiluminescent method for L-cysteine determination has been developed based on its enhancement of the electrochemiluminecence of luminol at a glassy carbon electrode. This method is simple and sensitive for cysteine determination. Under the selected experimental parameters, the linear range for cysteine concentration was 1.0 x 10-6 - 5.0 x 10-5 mol/l, and the detection limit was 0.67 µmol/l (S/N = 3). The relative standard deviation for 11 measurements of 1.0 x 10-5 mol/l cysteine was 4.5%. The proposed method has been applied to the detection of cysteine in pharmaceutical injections with satisfactory results.