Microextraction by packed sorbent followed by ultra high performance liquid chromatography for the fast extraction and determination of six antidepressants in urine.

The growing use of antidepressants in recent years has led to their increasing presence in forensic analyses. In this work, microextraction by packed sorbent followed by ultra-performance liquid chromatography with photodiode array detection provided a fast method for determining the antidepressants mirtazapine, venlafaxine, escitalopram, fluoxetine, fluvoxamine, and sertraline in human urine. The microextraction conditions (viz., type of sorbent, number of draw-eject extraction cycles or strokes, sample volume and pH, and type and volume of washing solution and eluent) were optimized by using an experimental design. The ensuing analytical method was validated in terms of linearity (25-1000 ng/mL urine), limit of detection (lower than 7.1 ng/mL), limit of quantification (25 ng/mL), precision (4.7-15.1% as relative standard deviation), and accuracy (80.4-126.1% as mean recovery for four replicate determinations). The proposed method allowed the six target antidepressants to be determined at concentrations from therapeutic to toxic levels. The application to small volumes (300 µL) of urine afforded fast extraction of the analytes and provided results on a par with those of existing clinical and forensic alternatives.