Development of a molecularly imprinted polymer-matrix solid phase dispersion method for selective determination of ß-estradiol as anabolic growth promoter in goat milk

Abstract

A simple, fast and sensitive method for the determination of 17 ß-estradiol (E2) from goat milk samples was developed by selective molecularly imprinted matrix solid-phase dispersion (MIP-MSPD) coupled with liquid chromatographic-DAD determination. The molecularly imprinted polymer was synthesized using 17ß-estradiol as template molecule, methacrylic acid as functional monomer, ethyleneglycol dimethacrylate as crosslinker monomer, azobisisobutyronitrile as initiator and acetonitrile as porogen, and was applied as selective solid support for matrix solid phase dispersion. The selected dispersant showed high affinity to E2 in goat milk matrix and the obtained extract was sufficiently clean to be directly injected into HPLC for further analysis, without any interferences from the matrix. The proposed MIP-MSPD method has been validated according to European Commission Decision 2002/657/EC criteria, in terms of linearity, precision, accuracy, decision limit (CC¿) and detection capability (CCß). Linearity ranged from 0.3- 10 ¿g g-1 with the correlation coefficient r2> 0.999. Mean recoveries of E2 from goat milk samples at different spiked levels were between from 89.5-92.2 % with RSD values within 1.3-2 %. CC¿ and CCß values were 0.36 and 0.39 ¿g g-1, respectively. The developed MIP-MSPD method was successfully applied to direct determination of E2 in goat milk samples.