Selective solid-phase extraction using molecular imprinted polymer for the analysis of diethylstilbestrol

A simple imprinted amino-functionalized silica gel material was synthesized by combining a surface molecular imprinting technique with a sol-gel process for solid-phase extraction-high performance liquid chromatography (SPE-HPLC) determination of diethylstilbestrol (DES). Activated silica gel was used as the supporter and non-imprinted silica sorbent was synthesized without the addition of DES using the same procedure as that of DES-imprinted silica sorbent. Compared with non-imprinted polymer particles, the prepared DES-imprinted silica sorbent showed high adsorption capacity, significant selectivity, good site accessibility and fast binding kinetics for DES. The maximum static adsorption capacity of the DES-imprinted and non-imprinted silica sorbent for DES was 62.58 mg g(-1) and 19.89 mg g(-1), respectively. The relatively selective factor value of this DES-imprinted silica sorbent was 61.7 at the level of 50 mg L-1. And the uptake kinetics was fairly rapid so that the adsorbent equilibrium was achieved within 10 min. Furthermore, the DES-imprinted polymers were used as the sorbent in solid-phase extraction to determine DES in fish samples. The MIP-SPE-HPLC method showed higher selectivity and good recoveries higher than 87.5% (R.S.D. 11.6%). (C) 2007 Elsevier Ltd. All rights reserved.