Diaw P A, Mbaye O M A, Gaye-Seye M D, Aaron J-J, Coly A, Tine A, Oturan N, Oturan M A
Laboratoire de Photochimie et d'Analyse, Département de Chimie, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal.
J Fluoresc. 2014 Jul;24(4):1319-30. doi: 10.1007/s10895-014-1418-8. Epub 2014 Jun 13.
A photo-induced fluorescence (PIF) method was developed for the determination of two benzoyl- and phenylurea pesticides, namely diflubenzuron (DFB) and fenuron (FEN). The photoconversion under UV irradiation of both pesticides into strongly fluorescent photoproducts was performed in several media (methanol, ethanol, acetonitrile, pH4 aqueous solution and pH4 water-methanol (30:70, v/v) mixture). PIF parameters were optimized. Analytical figures of merit for the PIF determination of DFB and FEN were satisfactory, with rather wide linear dynamic range (LDR) values of one to two orders of magnitude, relatively low limit of detection (LOD) values of, respectively, 9-24 ng/mL for DFB and 1-28 ng/mL for FEN, and limit of quantification (LOQ) values of, respectively, 30-80 ng/mL for DFB and 4-95 ng/mL for FEN, according to the medium. Relative standard deviation (RSD) values were in the range 1.7-5.6%. PIF was validated by comparing its analytical performances to those of a standard UV absorption spectrophotometric method. The optimized PIF method was applied to the quantitative analysis of both pesticides in various spiked natural water samples collected in a Senegal agricultural area by the standard addition procedure prior to extraction steps in dichloromethane, with satisfactory mean recovery percentage values (97.0-105.3 for DFB and 98.3-102.8% for FEN). An interference study of foreign species, including pesticides and inorganic ions, likely to be present in natural waters, was also carried out.
开发了一种光诱导荧光（PIF）方法用于测定两种苯甲酰脲类和苯基脲类农药，即除虫脲（DFB）和非草隆（FEN）。在几种介质（甲醇、乙醇、乙腈、pH4水溶液和pH4水 - 甲醇（30:70，v/v）混合物）中，将两种农药在紫外光照射下光转化为强荧光光产物。对PIF参数进行了优化。PIF测定DFB和FEN的分析性能指标令人满意，线性动态范围（LDR）相当宽，为一到两个数量级，检测限（LOD）相对较低，DFB分别为9 - 24 ng/mL，FEN为1 - 28 ng/mL，定量限（LOQ）分别为，根据介质不同，DFB为30 - 80 ng/mL，FEN为4 - 95 ng/mL。相对标准偏差（RSD）值在1.7 - 5.6%范围内。通过将其分析性能与标准紫外吸收分光光度法进行比较，对PIF进行了验证。优化后的PIF方法应用于塞内加尔农业地区采集的各种加标天然水样中两种农药的定量分析，采用标准加入法，在二氯甲烷萃取步骤之前进行，平均回收率令人满意（DFB为97.0 - 105.3%，FEN为98.3 - 102.8%）。还对外来物种进行了干扰研究，包括天然水中可能存在的农药和无机离子。
