Amperometric flow detection with a copper working electrode-response mechanism and application to various compounds.
The mechanism of amperometric detection with a copper electrode has been studied with four amino-acids in four different carrier liquids containing aqueous buffer and methanol. It is concluded that the response is produced by complexation of the test substances with cupric ions in the outer, porous layer of the passivating film, with formation of CuL(+) species. The increase in detector current is primarily determined by the complexation kinetics and to a lesser degree by the stability of the complex formed. The complexation rate strongly decreases with increasing amounts of organic solvent in the carrier liquid. The optimal detection conditions are discussed on the basis of the detection mechanism. Results are given for the detection of various structural types of amines and amino-alcohols.
Stulík
K
K
Department of Analytical Chemistry, Charles University, Albertov 2030, 128 40 Prague 2, Czechoslovakia.
Pacáková
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V
Le
K
K
Hennisen
B
B