特丁津分子印迹整体萃取棒的研制及其萃取性能

Preparation of Terbuthylazine Molecularly Imprinted Monolithic Bar and its Extraction Property

以特丁津为模板分子,甲基丙烯酸为功能单体,三羟甲基丙烷三甲基丙烯酸酯为交联剂,甲苯为致孔剂,在75℃下封管聚合反应24h后,以HF溶液腐蚀除去玻璃毛细管,制备得到分子印迹整体萃取棒,优化了聚合配方和合成条件。采用扫描电镜表征了萃取棒表面形貌,结果表明:萃取棒表面呈疏松、多孔的结构。研究了特丁津分子印迹整体萃取棒作为三嗪类除草剂样品前处理分离介质的萃取条件和萃取性能。采用甲苯为萃取剂,萃取60min后以150μL甲醇解吸。与不加模板分子的整体萃取棒相比,分子印迹整体萃取棒对模板分子特丁津及其结构类似物西玛津、西草净、莠去津、莠灭净、扑灭津及特丁净表现出选择性识别能力,富集率分别提高到1.5～8.1倍,对氯三嗪的萃取选择性优于硫三嗪。

The molecularly imprinted monolithic bar was prepared by blocking-tube polymerization at 75 ℃ for 24 h using terbuthylazine as template, methacrylic acid （MAA） as monomer and trimethylolpropane trime-thacrylate（TRIM） as cross-linker respectively. Preparing material and conditions were researched. The surface structure of the monolithic bar was investigated by scanning electron micrograph and it showed a porous structure. The extraction conditions and properties of the molecularly imprinted monolithic bar for enrichment of triazines was investigated. Extraction was performed in toluene for 60 min and the analytes were then desorbed by 150 μL methanol. Results indicated special selectivity towards terbuthylazine and its analogs such as simazine, simetryn, atrazine, ametryn, propazine and terbutryn was obtained for the molecularly imprinted monolithic bar compared to the non-imprinted monolithic bar. The enrichment efficiency of the molecularly imprinted monolithic bar for triazines was 1.5 to 8.1 times as that of the non-imprinted monolithic bar. Better selectivity was obtained for chlorotriazines than that of thiotrizaines. The molecularly imprinted monolithic bar was effective and selective for the enrichment of spiked lettuce. It showed potential application to the analysis of trace triazines in complex matrix.