Determination of albumin in biological fluids by flow injection analysis using the peroxyoxalate chemiluminescent system in micellar medium

Abstract

A new sensitive analytical procedure for the determination of albumin is presented, based on the participation of a fluorescent derivative of the protein in the peroxyoxalate chemiluminescent system using imidazole as a catalyst. The chemiluminescent emission is detected in a flow injection analysis (FIA) system, employing micellar medium as carrier, whereas the derivatisation reaction is carried out off-line using fluorescamine as a label. The optimisation of the operational and chemical variables of the method such as concentration of reagents, flow-rates, injection volume, etc., involves the use of experimental designs, including Draper-Lin small composite design, scarcely used in analytical chemistry. The performance characteristics were established and a detection limit of about 0.1 fmol of albumin was obtained. The method has been validated and satisfactorily applied to the determination of albumin in human serum and urine.

Effect of some surfactants on the chemiluminescent reactions of bis(2,4,6-trichlorophenyl)oxalate and bis(2-nitrophenyl)oxalate with hydrogen peroxide

“…As the CL efficiency sharply decreases at pH higher than 7.5, small variations of the acidity conditions can lead to several errors in the interpretation of the data. Some alternative methods described in the literature using flowing streams, such as continuous flow, flow injection [28][29][30] analysis, and liquid chromatography, require an appropriated optimization of the experimental parameters.…”

“…35,36 There are some studies on analytical applications for the determination of fluorophores, proteins, and hydrogen peroxide in aqueous samples using the PO-CL reaction with the introduction of the micelles. [28][29][30][37][38][39][40][41][42][43][44] Sodium dodecyl sulfate (SDS) micellar medium was used as a carrier to avoid the rapid degradation of TCPO in water in a flow-injection analysis, [28][29][30]41 allowing the use of TCPO in the absence of organic solvent.…”