光谱法研究八元瓜环与硫堇及多菌灵的主客体相互作用

摘要

In this paper ,the interaction of cucurbit [8]uril(Q[8]) with thionine (TH) and carbendazim (CBZ) were investigated with fluorescence and UV‐Vis spectroscopy .The experimental results showed that the inclusion complex between Q [8] and TH informed was at molar ratios of 1 ∶ 2 in 0.01 mol ・ L - 1 hydrochloric acid solution .The fluorescence intensity of the Q [8]/TH complexes quenched when Q [8] was added to TH solution ,but fluorescence increasing of the Q [8]/TH complex with the addi‐tion of CBZ was observed .The fluorescence increasing values show a good linear relationship with the CBZ concentration within 0 ~ 3.5 μmol ・ L - 1 .The linear regression equation relating fluorescence intensity (If ) to CBZ concentration (c) is If = 0.45c +32.24 (r= 0.999) .The detection limit was 9.39 × 10 - 8 mol ・ L - 1 .Forthemore ,the influence of foreign species on the analytical signal of the Q [8]/TH complex in the presence of carbendazim was established .No interference was observed from commonly used foreign species such as metal ions (Fe3 + ,Mg2 + ,Ca2 + ) .In particular ,benzimidazole compounds thiabendazole and fube‐ridazole do not interfere with CBZ determination at a specific concentration .The results revealed that complexation of Q [8] and TH with CBZ offers a fluorescent switching “on‐off” effect which will supply a potential application in pesticide residues test .%利用紫外‐可见吸收光谱法及荧光光谱法研究了八元瓜环与三环碱性染料硫堇及常用杀菌剂多菌灵的超分子相互作用，探讨了主客体相互作用的机制及光谱变化，并对其分析检测性能进行了研究。结果表明：在0.01 mol ・ L －1的盐酸溶液中，八元瓜环与硫堇形成了摩尔比为1∶2主客体复合物，且八元瓜环能使硫堇的荧光发生猝灭；在八元瓜环／硫堇体系中加入多菌灵后，多菌灵能使体系的荧光增强，从而形成了荧光的“开‐关”效应，其原因可能是由于八元瓜环与硫堇及多菌灵形成了主客体配合物而引起的。此外，测试了超分子体系的线性范围及检出限，并对酸度、共存物质对体系的影响进行了测试。结果表明多菌灵的浓度在0～3.5μmol ・ L －1范围内与体系荧光强度呈线性关系，线性方程为 If ＝0.45c ＋32.24，相关系数为0.999，检出限为9.39×10－8 mol ・ L －1。选择了常见离子及结构类似的苯并咪唑类杀菌剂对体系进行干扰测定，结果表明在一定浓度时，常见离子及结构类似的苯并咪唑类杀菌剂对多菌灵的检测不造成干扰。该结果为超分子配合物在农药残留检测方面的应用提供理论依据。