發(fā)布時間：2018-12-13 01:26

【摘要】：三嗪類除草劑在煙葉生產(chǎn)過程中的使用一方面可降低生產(chǎn)成本,另一方面可提高煙葉的產(chǎn)質(zhì)量。但是三嗪類除草劑化學(xué)結(jié)構(gòu)穩(wěn)定,易以痕量形式在植物體內(nèi)和環(huán)境中長期存留,且其具有擾亂人類內(nèi)分泌系統(tǒng)和生殖系統(tǒng)的作用。在建立三嗪類除草劑分析檢測方法的過程中,前處理的好壞直接影響到最終的檢測結(jié)果。目前傳統(tǒng)的針對三嗪類除草劑的前處理方法普遍選擇性不強,且尚未發(fā)現(xiàn)有應(yīng)用于煙葉基質(zhì)的。本文針對煙葉基質(zhì),建立了具有高選擇性的三嗪類除草劑分子印跡固相萃取(Molecularly Imprinted Solid Phase Extraction,MISPE)的前處理方法。主要研究內(nèi)容如下:(1)通過制備空白印跡聚合物(Nonimprinted Polymers,NIPs)探索得到了合適的聚合溶劑種類和用量。(2)以三嗪類除草劑莠去津為模板分子,甲基丙烯酸(MAA)為功能單體,乙二醇二甲基丙烯酸酯(EGDMA)為交聯(lián)劑,偶氮二異丁腈(AIBN)為引發(fā)劑,分別以乙腈和甲苯為聚合溶劑,采用本體聚合的方法制備了兩種莠去津分子印跡聚合物(Molecularly Imprinted Polymers,MIPs),并對這兩種MIPs進行掃描電鏡和紅外光譜表征以及熱重和壓汞分析。結(jié)果表明,得到的MIPs呈疏松多孔的結(jié)構(gòu),且模板分子被成功印跡于聚合物中。在300℃以下,MIPs具有良好的熱穩(wěn)定性。(3)對得到的兩種MIPs進行了吸附性能的研究。當(dāng)聚合用溶劑和吸附用溶劑相同時,MIPs顯示出最佳的吸附性能。在同一吸附溶液濃度下,以甲苯為聚合溶劑得到的MIPs飽和結(jié)合量遠大于以乙腈為聚合溶劑得到的MIPs。而以乙腈為聚合溶劑得到的MIPs的選擇性優(yōu)于以甲苯為聚合溶劑得到的MIPs。(4)將以甲苯為聚合溶劑得到的莠去津MIPs裝填于固相萃取(Solid Phase Extraction,SPE)空柱管中,采用MISPE的方法對煙葉中的12種三嗪類農(nóng)殘進行了前處理。在現(xiàn)有的實驗條件下,探索得到了最佳的淋洗和洗脫溶劑,分別為甲苯和二氯甲烷:乙酸=4:1(V:V)。(5)建立了煙葉中六種三嗪類農(nóng)殘的MISPE-HPLC的檢測方法。方法的加標(biāo)回收率為74.71%-110.70%,檢測限為0.125μg/g-0.47μg/g;相對標(biāo)準(zhǔn)偏差(RSD)為 5.6%-14.8%(n=3)。
[Abstract]:The application of triazine herbicides in tobacco production can reduce the production cost on the one hand and improve the quality of tobacco leaf on the other. However, the chemical structure of triazine herbicides is stable, easy to exist in plant and environment in trace form for a long time, and it has the function of disrupting human endocrine system and reproductive system. In the process of establishing a method for the analysis and detection of triazine herbicides, the quality of pretreatment has a direct impact on the final detection results. At present, the traditional pretreatment method for triazine herbicides is generally not selective, and has not been found to be used in tobacco matrix. In this paper, a preprocessing method for molecularly imprinted solid phase extraction (Molecularly Imprinted Solid Phase Extraction,MISPE) of triazine herbicides with high selectivity was established for tobacco matrix. The main research contents are as follows: (1) by preparing blank imprinted polymer (Nonimprinted Polymers,NIPs), suitable polymerization solvent and dosage were obtained. (2) Atrazine, a triazine herbicide, was used as template molecule. (MAA) as functional monomer, (EGDMA) as crosslinking agent, (AIBN) as initiator, acetonitrile and toluene as polymerization solvent, respectively. Two kinds of atrazine molecularly imprinted polymer (Molecularly Imprinted Polymers,MIPs) were prepared by bulk polymerization and characterized by scanning electron microscope (SEM), infrared spectroscopy (IR), thermogravimetry and mercury injection. The results showed that the MIPs was porous and the template molecule was imprinted successfully in the polymer. Under 300 鈩，

本文編號：2375611