Hydrophobic natural deep eutectic-solvent bar microextraction combined with HPLC-DAD for determination of urinary 1-hydroxypyrene of smokers

1-hydroxypyrene (1-OHP) is a metabolite of pyrene, which is a type of polycyclic aromatic hydrocarbons (PAHs) found in tobacco smoke and preferred use as a biomarker to determine exposure to PAHs from smoking. This paper reports a new and simple microextraction technique for 1-hydroxypyrene (1-OHP) determination in smokers' urines using hydrophobic natural deep eutectic solvent (HNDES) in developing solvent bar microextraction (SBME) and high performance liquid chromatography-diode array detection (HPLC-DAD). Terpenoids based-HNDES using various ratios of (thymol/menthol) were synthesized and investigated as extraction solvents. The variables affecting HNDE-SBME steps were optimized by response surface methodology (RSM) based on central composite design (CCD). Under the optimum conditions, the calibration graph of spiked urine samples was linear in the range of 0.3–25.0 μg L−1 1-OHP with a correlation coefficient of 0.999. Additionally, the detection limit, quantitation limit, and extraction recovery were found to be 0.06 μg L−1, 0.22 μg L−1, and ≥100%, respectively. In comparison with referenced methods and based on the satisfactory results of applications, the proposed method can be considered as a potential method for the detection of urinary 1-OHP for health risk assessment of PAHs exposures