Fan Jing, Shao Xiaojing, Xu Haizhu, Feng Suling
School of Chemistry and Environmental Science, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan 453007, People's Republic of China.
Luminescence. 2009 Jul-Aug;24(4):266-70. doi: 10.1002/bio.1120.
A novel inhibitory kinetic fluorimetric method for the determination of trace methomyl was proposed. It was shown that the Fenton reagent oxidized rhodamine B in acid medium which enabled the fluorescence quenching of the latter. The presence of trace methomyl clearly inhibited the reaction. Upon addition of EDTA, a good linear relationship between the inhibitory effect and the concentration of methomyl was observed, together with improved stabilization and sensitivity. Factors affecting the determination of trace methomyl were investigated systematically. Under the optimum conditions, the linear range for the determination of methomyl was 0.04-2.2 microg/mL; the detection limit and the quantification limit for methomyl were 0.011 and 0.037 microg/mL, respectively. The proposed method was applied to the determination of methomyl in four environmental soil samples, six environmental water samples and one synthetic sample; the results were compared with those determined by the HPLC method. The recoveries and the relative errors were 83.5-101.2 and 0.47-2.02%, respectively. The possible reaction mechanism has also been discussed.
提出了一种测定痕量灭多威的新型抑制动力学荧光分析法。结果表明，在酸性介质中，芬顿试剂氧化罗丹明B，导致后者荧光猝灭。痕量灭多威的存在明显抑制了该反应。加入乙二胺四乙酸（EDTA）后，观察到抑制作用与灭多威浓度之间具有良好的线性关系，同时稳定性和灵敏度得到提高。系统研究了影响痕量灭多威测定的因素。在最佳条件下，灭多威的测定线性范围为0.04 - 2.2μg/mL；灭多威的检出限和定量限分别为0.011和0.037μg/mL。该方法应用于四个环境土壤样品、六个环境水样和一个合成样品中灭多威的测定；并将结果与高效液相色谱法（HPLC）测定结果进行了比较。回收率和相对误差分别为83.5 - 101.2%和0.47 - 2.02%。还讨论了可能的反应机理。
