Triazine-imprinted polymer

Fig. 20.8. Compounds examined using triazine-imprinted polymer.

The most widely employed techniques for the extraction of water samples for triazine compounds include liquid-liquid extraction (LLE), solid-phase extraction (SPE), and liquid-solid extraction (LSE). Although most reports involving SPE are off-line procedures, there is increasing interest and subsequently increasing numbers of reports regarding on-line SPE, the goal of which is to improve overall productivity and safety. To a lesser extent, solid-phase microextraction (SPME), supercritical fluid extraction (SEE), semi-permeable membrane device (SPMD), and molecularly imprinted polymer (MIP) techniques have been reported. 

Koeber R. et al., 2001. Evaluation of a multidimensional solid-phase extraction platform for highly selective online cleanup and high-throughput LC-MS analysis of triazines in river water samples using molecu-larly imprinted polymers. Anal Chem 73 2437. 

Chapuis F et al (2003) Optimization of the class-selective extraction of triazines from aqueous samples using a molecularly imprinted polymer by a comprehensive approach of the retention mechanism. J Chromatogr A 999( 1—2) 23—33... 

Chapuis F et al (2004) Retention mechanism of analytes in the solid-phase extraction process using molecularly imprinted polymers - application to the extraction of triazines from complex matrices. J Chromatogr B Anal Technol Biomed Life Sci 804(1) 93-101... 

PILETSKY S A, PILETSKAYA E V, EL SKAYA A V, LEVI R, YANO K and KARUBE I (1997), Optical detection system for triazine based on molecularly-imprinted polymers , Anal Lett, 30, 445-455. 

Bjamason, B., L. Chimuka, and O. Ramstrom (1999). On-line solid-phase extraction of triazine herbicides using amolecularly imprinted polymer for selective sample enrichment. Anal. Chem., 71 2152-2156. 

CHROMATOGRAPHIC RETENTION OF TRIAZINES (10 NMOLE INJECTED SEPARATELY) ON AME IMPRINTED POLYMERS PREPARED AT DIFFERENT PRESSURES [110]... 

The application of MIPs as the stationary phase in solid-phase extraction (SPE), often referred to as molecularly imprinted polymer solid-phase extraction (MIS P E), is a rapidly growing area [197-199]. With MISPE, highly specific enrichment of substances present at trace levels is possible. The technique has been applied to the analysis of drugs, for example, caffeine [200], scopolamine [201], naproxen [202], tetracycline [203], cholesterol [204] and local anesthetics [205], as well as environmental pollutants, exemplified by organophosphate flame retardants [206-208], triazines in soil and vegetable samples [71] and naphthalene sulfonates in river water [209]. 

Matsui J, Fujiwara K, Ugata S et al. Solid-Phase extraction with a dibutylmelamine-imprinted polymer as triazine herbicide-selective sorbent. J Chromatogr A 2000 889 25-31. 

In the second, more selective, approach a class-specific extraction with molecular imprinted polymers (MIPs) can be used [43,44] however, their use in environmental analysis has been rarely reported and so far limited to pesticide analysis. For example, Turiel et al. [45] developed a method for group-selective extraction of chlorotriazines and methylyhiotyrizines and their TPs in soils, obtaining recoveries higher than 94% for chlorotriazines and 39% for prometryn. Similarly, in the study of Chapuis et al. [46], the ametryn MIP was shown to be highly class-selective for triazines and their degradation products and was appUed to the clean-up of soil extracts. 

The monomers used to prepare the imprinted polymers for the triazine herbicides were acrylamidopropyl sulfonic acid (AMPS) and methylenebisacrylamide (BIS). This methodology has also been used in the synthesis of imprinted membranes used in the solid phase extraction of terbumeton, another member of the group of triazine herbicides form water [59]. 

Matsui, J. Fujiwara, K. Ugata, S. Takeuchi, T. Sohd-phase extraction with a dibutyl-melamine-imprinted polymer as triazine herbidde-selective sorbent. J. Chromatogr. A. 

Takeuchi and co-workers (18) coupled combinatorial techniques with molecular imprinted polymers to develop sensors for triazine herbicides. The library consisted of a 7 x 7 array containing different fractions of monomers methacrylic acid (MAA) and 2-(trifluoromethyl)acrylic acid (TFMAA) with constant concentrations of the imprint molecules ametryn or atrazine. After UV-initiated polymerization, the products from the sensor library were characterized by HPLC measurement of herbicide concentration. The receptor efficiency was observed to vary with monomer type the atrazine receptor efficiency increased with MAA composition and the ametryn receptor was enhanced by increased fractions of TFMAA. Although only monomer concentration was varied in the hbraries, the authors conclude that the CM synthetic approach would be usefiil in analyzing other variables such as solvent, cross-linking agent, and polymerization conditions to produce optimum molecularly imprinted polymer sensors. 

Turiel, E. et al.. Molecular recognition in a propazine-imprinted polymer and its application to the determination of triazines in environmental samples. Anal. Chem., 73, 5133, 2001. 

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