烟叶中三嗪类农残的分子印迹固相萃取检测技术及应用

发布时间：2018-12-13 01:26

【摘要】：三嗪类除草剂在烟叶生产过程中的使用一方面可降低生产成本,另一方面可提高烟叶的产质量。但是三嗪类除草剂化学结构稳定,易以痕量形式在植物体内和环境中长期存留,且其具有扰乱人类内分泌系统和生殖系统的作用。在建立三嗪类除草剂分析检测方法的过程中,前处理的好坏直接影响到最终的检测结果。目前传统的针对三嗪类除草剂的前处理方法普遍选择性不强,且尚未发现有应用于烟叶基质的。本文针对烟叶基质,建立了具有高选择性的三嗪类除草剂分子印迹固相萃取(Molecularly Imprinted Solid Phase Extraction,MISPE)的前处理方法。主要研究内容如下:(1)通过制备空白印迹聚合物(Nonimprinted Polymers,NIPs)探索得到了合适的聚合溶剂种类和用量。(2)以三嗪类除草剂莠去津为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,分别以乙腈和甲苯为聚合溶剂,采用本体聚合的方法制备了两种莠去津分子印迹聚合物(Molecularly Imprinted Polymers,MIPs),并对这两种MIPs进行扫描电镜和红外光谱表征以及热重和压汞分析。结果表明,得到的MIPs呈疏松多孔的结构,且模板分子被成功印迹于聚合物中。在300℃以下,MIPs具有良好的热稳定性。(3)对得到的两种MIPs进行了吸附性能的研究。当聚合用溶剂和吸附用溶剂相同时,MIPs显示出最佳的吸附性能。在同一吸附溶液浓度下,以甲苯为聚合溶剂得到的MIPs饱和结合量远大于以乙腈为聚合溶剂得到的MIPs。而以乙腈为聚合溶剂得到的MIPs的选择性优于以甲苯为聚合溶剂得到的MIPs。(4)将以甲苯为聚合溶剂得到的莠去津MIPs装填于固相萃取(Solid Phase Extraction,SPE)空柱管中,采用MISPE的方法对烟叶中的12种三嗪类农残进行了前处理。在现有的实验条件下,探索得到了最佳的淋洗和洗脱溶剂,分别为甲苯和二氯甲烷:乙酸=4:1(V:V)。(5)建立了烟叶中六种三嗪类农残的MISPE-HPLC的检测方法。方法的加标回收率为74.71%-110.70%,检测限为0.125μg/g-0.47μg/g;相对标准偏差(RSD)为 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，

本文编号：2375611