土壤中砜嘧磺隆和氯磺隆残留的光化学荧光分析方法研究

Determination of rimsulfuron and chlorsulfuron residues in soil by photochemical fluorescence method

用紫外线照射非荧光特性的砜嘧磺隆和氯磺隆,通过生成具有荧光特性的衍生物,分别研究了其在不同介质中的荧光特性及其影响因子,建立了测定土壤中砜嘧磺隆和氯磺隆残留的光化学荧光分析法(PCF)。结果表明:在2×10-3mol/L、一定酸碱度(砜嘧磺隆pH 7、氯磺隆pH 12)的十六烷基三甲基氯化铵(CTAC)胶体分散体系中,紫外照射150 s是PCF法测定砜嘧磺隆和氯磺隆残留的最佳条件,在此条件下砜嘧磺隆和氯磺隆的检出限(LOD)分别为0.7和0.6μg/kg,相对标准偏差(RSD)分别为1.7%和2.1%;在黄松田水稻土、黄红壤性水稻土和青紫泥田水稻土3种不同性质的土壤中,砜嘧磺隆和氯磺隆同时测定的平均回收率分别为99.0%±1.0%和98.7%±4.1%、97.6%±1.7%和97.0%±4.7%、96.7%±2.3%和95.4%±5.5%;所建立的PCF法可有效、快速测定土壤中同时残留的微量砜嘧磺隆和氯磺隆。

Fluorescent ramification was formed when rimsulfuron and chlorsulfuron was irradiated by ultraviolet radiation. The photochemical fluorescence（PCF） characteristics of fluorescent ramification in various solvents and relevant influenced factors were investigated. Thus, a novel PCF analytical method was developed to determinate rimsulfuron and chlorsulfuron residues in soil. It＇s found that cetyltrimethylammoniurn chloride （CTAC） colloidal dispersion （2 ×10^-3mol/L）, with a certain acidity or alkalinity （rimsulfuron pH 7, chlorsulfuron pH 12） and illuminating 150 s were the best conditions to determine the above two sulfonylurea herbicides by PCF method. Under the optimum experiment conditions, the limits of determination were O. 7 μg/kg and O. 6μg/kg, respectively, with relative standard deviations of 1.7% and 2.1%, respectively. The method was successfully applied to analyze rimsulfuron and chlorsulfuron residues in three different type soil samples （ i. e. , silty loam, yellowish red soil and purplish soil）. The average recoveries of rimsulfuron and chlorsulfuron in three different type soil samples were99.0% ±1.0% and 98.7% ±4. 1% ,97.6% ±1.7% and 97.0% ±4.7%, 96.7% ± 2.3% and 95.4% ± 5.5%, respectively. It indicated that the estabolished PCF analytical method was reliable and rapid in determination of rimsulfuron and chlorsulfuron residues in soil samples.