目前关于除草剂残留量测定的研究涉及的三氮苯类除草剂种类单一,不能全面考察土壤中三氮苯类除草剂微量残留的水平,基于此进行了题示研究。取10.0 g预处理后的样品,加入约12 g硅藻土混匀后,按设定的加速溶剂萃取程序于80 ℃萃取10 min。萃取液经凝胶渗透色谱净化,洗脱液于50 ℃氮吹至近干,残渣用1 mL体积比1∶2的丙酮-乙醇混合液涡旋溶解,采用气相色谱-串联质谱法(GC-MS/MS)同时测定滤液中西玛津、氰草津、莠去津、扑灭津和草达津等5种除草剂的含量。结果表明,5种除草剂的质量浓度在0.01~5.0 mg·L^-1内与对应的峰面积呈线性关系,检出限(3S/N)为0.010~0.014 mg·kg^-1。按照标准加入法进行回收试验,回收率为84.6%~103%。对0.1 mg·L^-1空白土壤加标样品平行测定6次,测定值的相对标准偏差均小于3.0%。方法用于实际食用菌种植土壤样品的分析,其中莠去津的检出量分别为0.015,0.011 mg·kg^-1,扑灭津的检出量为0.020 mg·kg^-1。

The research on the determination of triazene herbicide residues involves a single type of herbicide at present, which could not comprehensively examine the level of trace triazene herbicide residues in soil. Therefore, the study mentioned by title was done. The pre-treated sample (10.0 g) was taken, and about 12 g of diatomite was added. After mixing well, the mixture was extracted at 80 ℃ for 10 min according to the set accelerated solvent extraction procedure. The extraction solution was purified by gel permeation chromatography, and the eluent was blown to near dryness at 50 ℃ by nitrogen. The residue was dissolved by 1 mL of a mixture of acetone and ethanol at a volume ratio of 1∶2. Five herbicides in the filtrate, including simazine, cyanazine, atrazine, ipramazine, and oxalazine, were simultaneously determined by gas chromatography tandem mass spectrometry (GC-MS/MS). As shown by the results, linear relationships between values of peak area and mass concentration of five herbicides were found in the range of 0.01-5.0 mg·L^-1. with detection limits (3S/N) ranged from 0.010 to 0.014 mg·kg^-1. Test for recovery was made by standard addition method, giving results in the range of 84.6%-103%. The 0.1 mg·L^-1 blank soil sample was parallel determined 6 times, with RSDs of the determined values less than 3.0%. The method was applied to the analysis of soil samples from actual edible fungus planting soil samples, with detection amounts of 0.015, 0.011 mg·kg^-1 for atrazine and 0.020 mg·kg^-1 for chlorpyrifos, respectively.