Determination of urinary trans,trans-muconic acid using molecularly imprinted polymer in microextraction by packed sorbent followed by liquid chromatography with ultraviolet detection

trans,trans-Muconic acid (tt-MA) has been introduced as biological exposure index for workers exposed to benzene. In the present study, for the first time, a novel and easy-to-use analytical method based on molecularly imprinted polymer (MIP) in microextraction by packed sorbent (MEPS), followed by high-performance liquid chromatography with ultra-violet detection (MIMEPS-HPLC-UV) was developed to determine tt-MA in urine samples. Fourier transform infrared spectroscopy was used for MIP characterization. The imprinting effect on the MIP was also evaluated. Furthermore, various parameters that affect the MEPS performance were investigated, including extraction cycles, sample volume, as well as the type and volume of washing and elution solvents. The optimised procedure was selective, sensitive, rapid and both user- and environmentally-friendly. A seven-point calibration curve was obtained in the range of 0.015-2 μg/mL (R2 = 0.9986). The extraction recovery was >89.8%. The limit of detection and limit of quantitation for tt-MA were 0.015 and 0.05 μg/mL, respectively. The within- and between-day precisions, given as percent relative standard deviation, were in the range of 3.4-4.7% and 3.5-6.6%, respectively. Accuracy was −8.4 to −10.2% in urine samples. The developed method is suggested as an alternative to existing conventional SPE methods for biomonitoring of benzene-exposed subjects.