Molecularly Imprinted Solid Phase Extraction Before Capillary Electrophoresis for the Analysis of Estrogens in Serum Samples

An estrogen selected molecular imprinted polymer (MIP) has been developed to be used as an alternative sorbent in solid phase extraction of serum samples before capillary electrophoresis analysis. Following a heat polymerization, MIP has been synthesized using methacrylic acid (MAA) as functional monomer, ethyleneglycol dimethacrylate (EGDMA) as crosslinker, benzoyl peroxide as radical initiator and 17β- estradiol as template, and toluene as porogen. The optimized molecular imprinted solid phase extraction (MISPE) was compared to traditional C18 solid phase extraction to purify estrogens from complex matrices. It was concluded that the MISPE system developed is useful for the selective extraction of 17β- estradiol and its major natural related estrogens, estriol and estrone, from serum samples with minimal interferences and high recoveries.