High-performance liquid chromatographic method for post-column, in-line derivatization with o-phthalaldehyde and fluorometric detection of phenylpropanolamine in human urine.

A rapid and sensitive method for the analysis of phenylpropanolamine in urine was developed using high-pressure liquid chromatography, post-column, in-line derivatization with o-phthalaldehyde, followed by detection with a fluorometer. Human urine was injected directly into the chromatographic system, and phenylpropanolamine separated in the reversed-phase mode. The practical lower limit of detection was 0.1 microgram/ml of urine. The coefficient of variation from 0.96 to 96 micrograms/ml varied between 2.23 and 0.19%, respectively. The linearity of the calibration graphs is excellent (r = 0.9999) over a concentration range of two orders of magnitude.