Microextraction by packed sorbent using a new restricted molecularly imprinted polymer for the determination of estrogens from human urine samples

Microextraction by packed sorbent (MEPS) was employed with a new restricted access molecularly imprinted polymer (MIP) for the determination of estrone (E1) and estriol (E3) from human urine samples. Several parameters affecting the extraction efficiency during the procedure of sample preparation were systematically optimized, including washing solvent, sample volume, amount of sorption material, elution solution, eluent volume, number of cycles of aspersion/dispersion and sample pH. Mean recoveries with their respective relative standard deviations (RSD%) for E1 and E3 were 79.5 +/- 7.1% and 69.5 +/- 1.5%, respectively. The method was linear in the concentration range of 100 to 1100 ng mL(-1) for each hormone, with correlation coefficient of 0.9954 and 0.9952 for E1 and E3, respectively. The developed method was successfully applied in urine sample from volunteer pregnant.