Rapid ultraviolet monitoring of multiple psychotropic drugs with a renewable microfluidic device

A rapid method for sensitive ultraviolet detection of multiple psychotropic drugs in human plasma was developed on a low-cost and expediently fabricated hybrid microfluidic device. The device was composed of one fused-silica capillary with a sampling fracture, a poly(methyl methacrylate) board with four reservoirs, and a printed circuit board. At the optimal separation and detection conditions, the baseline separation of three kinds of psychotropic drugs including barbiturates (phenobarbital and barbital), benzodiazepines (nitrazepam, clonazepam, chlordiazepoxide, alprazolam and diazepam) and tricyclic antidepressant drugs (amitriptyline) was achieved within 200 s with separation efficiency up to 3.80 × 105 plates m−1. The linear ranges for ultraviolet detection were from 2.0 to 1000.0 μg mL−1 for chlordiazepoxide and 1.0 to 1000.0 μg mL−1 for other seven drugs. Combining with solid-phase extraction, this novel protocol could successfully be used to screen naturally existing psychotropic drugs in a known human plasma sample. The minimum detectable concentration was down to 27 ng mL−1 for phenobarbital spiked in plasma. This work provided a promising way to initially screen different psychotropic drugs with high resolution, rapid separation and low-cost.