Fluorescence Analysis for p ‐Hydroxymethamphetamine in Urine by HPLC with Post‐Column Reaction

Abstract A high selectivity analytical method for p‐hydroxymethamphetamine (pOHMA) in urine is presented. After extraction, the analyte was analyzed by high performance liquid chromatography with post‐column oxidation using potassium hexacyanoferrate(III) and sodium hydroxide to detect the fluorophor of pOHMA. The recovery of pOHMA is 86.5%, and the calibration curve for pOHMA is linear in the range of 5–75 µg/mL (r 2=0.997). The coefficients of variation determined for spiked samples are 2.2% for 10 µg/mL and 2.3% for 5 µg/mL pOHMA (each n=5), and the detection limit for pOHMA is 1 µg/mL (20 ng; S/N=3). Analysis for pOHMA in forensic samples is performed successfully, without interference from endogenous fluorophors, yielding concentrations in the appropriate range for methamphetamine abusers.