Ultrasensitive assay of azithromycin in medicine and bio-fluids based on its enhanced luminol-H(2)O(2) chemiluminescence reaction using flow injection technique.

A simple flow injection chemiluminescence method with synergistic enhancement has been investigated for the rapid and sensitive determination of azithromycin. The synergistic action was significant in the chemiluminescence system of luminol-hydrogen peroxide with azithromycin as an enhancer. The enhanced chemiluminescence intensity was linear with the concentration of azithromycin over the range from 0.1 pg x mL(-1) to 1.0 ng x mL(-1) (r(2=)0.9988) with a detection limit (3sigma) of 0.04 pg x mL(-1). At a flow rate of 2.0 mL x min(-1), a complete analytical process could be performed within 0.5 min, including sampling and washing, with a relative standard deviation of less than 3.0%. The proposed method was applied successfully in the assay of azithromycin in pharmaceutical preparations, human urine and serum without any pre-treatment procedure.