Flow‐injection chemiluminescence determination of melamine in urine and plasma

A novel flow‐injection chemiluminescence method for the determination of melamine in urine and plasma was developed. It was found that melamine can remarkably enhance chemiluminescence emission from the luminol–K 3 Fe(CN) 6 system in an alkaline medium. Under the optimum conditions, chemiluminescence intensity had a good linear relationship with the concentration of melamine in the range 9.0 × 10 –9 –7.0 × 10 –6  g/mL, with a correlation coefficient of 0.9992. The detection limit (3 σ ) was 3.5 ng/mL. The method has been applied to determine the concentration of melamine in samples using liquid–liquid extraction. Average recoveries of melamine were 102.6% in urine samples and 95.1% in plasma samples. The method provided a reproducible and stable approach for the sensitive detection of melamine in urine and plasma samples. Copyright © 2011 John Wiley & Sons, Ltd.