Simultaneous monitoring of selective serotonin reuptake inhibitors in human urine, plasma and oral fluid by reverse-phase high performance liquid chromatography.

A simple and rapid reverse-phase high-performance liquid chromatography method is developed for the simultaneous determination of selective serotonin reuptake inhibitors (sertraline, citalopram, paroxetine and fluoxetine) in urine, plasma and oral fluid. Separation was performed on a Crestpack-18 column (4.6 × 250 mm × 5 µ) within 17.5 min. The mobile phase was composed of water (50 mL) [with glacial acetic acid (0.15 mL) + triethyl amine (0.30 mL)]-acetonitrile (40 mL)-methanol (10 mL), delivered isocratically (0.6 mL/min) at 270 nm. Liquid-liquid extraction was performed for isolation of analytes from biofluids. The developed methodology was validated in terms of sensitivity, linearity, accuracy, precision, stability and selectivity. The calibration curves were linear in the range of 5-1,000 ng/mL for all the compounds in three matrices, with coefficients of determination between 0.9991 to 0.9998. The average extraction recoveries for all the four analytes were above 90%. The limits of detection and limits of quantification were in the ranges of 0.02-1.20 and 0.12-2.51 ng/mL, respectively. The intra-day and inter-day variation coefficients were less than 8.0 and 11%, respectively. Moreover, the results were compared statistically for each analyte in three matrices and found to be equivalent, which signifies the absence of matrix effect. Thus, the method can be applied for the determination of selective serotonin reuptake inhibitors in urine, plasma and oral fluid for routine therapeutic and toxicological screening.