Two-phase hollow fiber based liquid phase microextraction using hydrophobic deep eutectic solvents for extraction of trace amounts of benzodiazepines in biological samples.

This study carefully prepared hydrophobic deep eutectic solvents (H-DESs) for the acceptor phase in two-phase hollow fiber liquid phase microextraction (HF-LPME). This innovative approach was used for the extraction of benzodiazepines from biological samples. H-DESs were synthesized using five different compounds: menthol, choline chloride, lauric acid, decanoic acid, and octanoic acid, which were in specific molar ratios. High-performance liquid chromatography with UV detection was employed to analyze the extracted analytes. Various parameters influencing the extraction efficiency of benzodiazepine were carefully optimized and investigated. Under the optimized conditions, a linear dynamic range of 1-1000 μg/L was achieved with correlation coefficients greater than 0.991. Quantitation limits in the 1-5 μg/L range and detection limits between 0.3 and 1.5 μg/L were obtained. Preconcentration factors in the range of 89-145 were also obtained. The method was employed for the extraction and determination of benzodiazepines biological samples, resulting in favorable results.