Sensitive determination of probenecid in urine samples by reversed-phase liquid chromatography and UV-visible detection using solid-phase extraction techniques for sample clean-up

Summary This study describes a rapid method for the determination of probenecid in human urine by liquid chromatography with UV detection at 254 nm, after clean-up through a C8 solid-phase extraction column. Liquid chromatography was carried out on a C18-bonded phase using an acetonitrile-acetate buffer (pH=4) gradient elution. Ethacrynic acid was used as internal standard. The system has been applied to the determination of probenecid in the 0.10–100.0 g/ml concentration range; the limit of detection was 5 ng/mL.