Available online at www.sciencedirect.com Talanta 75 (2008) 978–986 Application of multivariate analysis to the screening of molecularly imprinted polymers (MIPs) for ametryn A.R. Koohpaei a,1 , S.J. Shahtaheri b,∗ , M.R. Ganjali c , A. Rahimi Forushani d , F. Golbabaei a a Department of Occupational Health, School of Public Health, Medical Sciences, University of Tehran, Tehran, Iran b Department of Occupational Health, School of Public Health, Center for Environmental Research, Medical Sciences/University of Tehran, Tehran, Iran c Center of Excellence in Electrochemistry, Endocrine & Metabolism Research Center, University of Tehran, Tehran, Iran d Department of Biostatistics, School of Public Health, Medical Sciences, University of Tehran, Tehran, Iran Received 10 September 2007; received in revised form 2 December 2007; accepted 24 December 2007 Available online 14 January 2008 Abstract Among the solid-phase extraction (SPE) techniques, a novel system for a triazine herbicide named ametryn, has been developed based on a molecular imprinted polymer (MIP) phase. Through this method, the synthesis of the complementary to ametryn MIP was accomplished and the factors influencing its efficiency have been optimized. Through the optimization process, the type and the amounts of functional monomer and solvents, template amount, cross-linker, initiator as well as the polymerization temperature were considered to be evaluated. Based on the obtained results, the optimum conditions for the efficient polymerized sorbent, considering the recovery efficiency were solvent: acetonitrile, 6.41 mL; monomer: methacrylic acid, 5.41 mmol; template: 1.204 mmol; cross-linker: 27.070 mmol; initiator: 2.03 mmol; temperature: 40.86 ◦ C. The optimum molar ratio among the template, monomer and cross-linker for ametryn was 1:4.49:22.48. The reversed-phase HPLC-UV was used for the ametryn determination, using an isocratic solvent delivery system (acetonitrile: H 2 O, 60:40), flow-rate of 0.8 mL min -1 and a UV wavelength of 220 nm. In line with the obtained results, using central composite design (CCD) can increase the precision and accuracy of synthesis and optimization of MIP to ametryn and possibly other similar analogues. © 2008 Elsevier B.V. All rights reserved. Keywords: Molecular imprinted polymers; Solid-phase extraction; Central composite design; Herbicides; Triazine; Ametryn 1. Introduction The most widely used group of herbicides, since their dis- covery in the 1950s, is triazines including ametryn, atrazine, simazine, cyanazine and propazine. Triazinic herbicides were considered as systemic toxicants, causing a variety of acute health effects. On the other hand, the analysis of herbicides, in order to monitor, assess, evaluate and control their effects in the environment, is one of the most important fields in analytical chemistry [1]. In occupational and environmental assessment, a large number of samples are needed. Consequently, inexpensive and rapid analytical techniques are required [2]. In some efforts to reduce the cost, time and use of organic solvents in the organic ∗ Corresponding author. Tel.: +98 91 21779019; fax: +98 21 88951390. E-mail address: shahtaheri@tums.ac.ir (S.J. Shahtaheri). 1 Present address: Department of Occupational Health, Qom University of Medical Sciences, Qom, Iran. trace analysis, many researchers have developed miniature meth- ods, requiring fewer sample amounts and thus, less extracting solvents to carry out their analyses. In addition, new approaches such as solid-phase extraction (SPE), supercritical fluid extrac- tion (SFE), accelerated solvent extraction (ASE) and solid-phase microextraction (SPME) using polymer-coated fibers have been investigated, demonstrating more promising approaches in the environmental analysis [3]. Other approaches, which are gaining popularity for the sample clean-up, include the immunoaffinity chromatography [4–6] and the molecular imprinting polymers (MIPs). In the MIP technique, functional monomers and cross-linkers are polymerized in the presence of a template molecule, which is followed by the template removal from the resultant polymer network to leave a template-fitted cavity. The molecular imprint- ing technology is less expensive than the antibody production and may offer an alternative when the cost of the antibody pro- duction is prohibitive or the antibody performance is a problem. 0039-9140/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.talanta.2007.12.046