Preparation of a New Solid-Phase Microextraction Fiber Based on Molecularly Imprinted Polymers for Monitoring of Phenobarbital in Urine Samples.

This article focuses on the development and evaluation of a molecularly imprinted polymer solid-phase microextraction (MIP-SPME) fiber for selective extraction and determination of phenobarbital in human urine samples. The fiber was fabricated by sol–gel polymerization of 3-aminopropyltriethoxysilane (APTES) and tetraethyl orthosilicate (TEOS) on a modified stainless-steel wire, providing enhanced mechanical stability and chemical resistance. Optimized extraction conditions yielded high selectivity, sensitivity (limit of detection 9.88 ng/mL), and good reproducibility, with phenobarbital quantification performed via high-performance liquid chromatography with ultraviolet detection (HPLC-UV). The method demonstrated excellent recovery rates (94.2–98.5%) in spiked urine samples and compared favorably with existing phenobarbital detection techniques in terms of linear range, solvent consumption, and operational simplicity.