HPLC determination of selected amines with enzymatic biosensor and amperometric detection

Diamine oxidase (DAO) obtained from lentil has been employed to the preparation of graphite paste amperometric biosensor, which has been utilised in the reversed phase HPLC system for detection of several amines: dopamine, benzylamine, benzylhydrazine and tyramine previously separated on various commercially available columns. Satisfactory results were obtained on Waters SymmetryShield RP8 column and monolithic Merck Chromolith column. The application of biosensor allows the selective detection of amines in complex blood serum matrix to be performed. [...

Carbon Ceramic Electrodes Modified with Laccase fromTrametes hirsuta: Fabrication, Characterization and Their Use for Phenolic Compounds Detection

Fungal laccase (Lc) from the basidiomycete Trametes hirsuta was immobilized on top of a carbon ceramic electrode using physical absorption. Direct, unmediated heterogeneous electron transfer between Lc and the carbon ceramic electrode (CCE) under aerobic conditions was shown. The bioelectrocatalytic reduction of oxygen on Lc-CCE started at about 430 mV vs. Ag vertical bar AgCl vertical bar KClsat at pH 3.5 and moved with about 57 mV in the cathodic region per pH unit. The Lc-modified CCE was then used as a biosensing detection element in a single line flow injection system for the amperometric determination of a variety of phenolic substrates of the enzyme. The experimental conditions were studied and optimized for catechol serving as a model compound. Statistical aspects were applied and the sensor characteristics and Michaelis-Menten constants of the investigated phenolic compounds were calculated and compared with those obtained for solid graphite electrodes modified with Trametes hirsuta laccase. The results showed that the CCE based biosensor in comparison with the solid graphite based biosensor offers a lower detection limit, a wider linear dynamic range, and excellent operational stability with no sensor passivation, indicating that the sol - gel lattice improves the electrochemical behavior of the biosensor

ELECTROANALYTICAL FLOW MEASUREMENTS

A review based on 94 cited original papers describes recent achievements in application of different electrochemical detection in flow analysis, injection techniques of flow analysis, liquid chromatography and capillary electrophoresis