Reagentless chemiluminescence flow sensor for the determination of riboflavin in pharmaceutical preparations and human urine

A novel continuous-flow sensor based on chemiluminescence (CL) detection wa s developed for the determination of riboflavin at pg ml(-1) levels by the immobilization of the reagents. It was found that the CL intensity from the oxidation between luminol and per-iodate could be enhanced in the presence of riboflavin. The increase of CL emission was correlated with the ribofla vin concentration in the range from 0.04 to 200 ng ml(-1), and the detectio n limit was 0.02 ng ml(-1) (3s). Considering the effective reaction ions, l uminol and IO4- was immobilized on anion-exchange resin. The system could p roduce an evident CL signal by water as eluant and it was also shown that t he flow sensor could greatly improve the selectivity and sensitivity for de termination of riboflavin with a high signal-to-noise ratio. A complete ana lysis, including sampling and washing, could be performed in 0.5 min with a relative standard deviation of less tl an 3.0%. The flow sensor was applie d successfully to the determination of riboflavin in pharmaceutical prepara tions and human urine samples.