毛细管气相色谱法测定唑草酮在甘蔗及其土壤中的残留量

Determination of Carfentrazone-ethyl Residues in Sugarcane and Soil Sample by Capillary GC Method

为建立唑草酮在甘蔗及其土壤中残留的分析方法,用甲醇∶水=4∶1(v/v)溶液提取甘蔗及其土壤中的唑草酮,然后用石油醚∶二氯甲烷=4∶1(v/v)萃取。石油醚和二氯甲烷相经浓缩后过弗罗里硅土柱净化,毛细管柱分离,用微池电子捕获检测器(μECD)测定。结果表明:唑草酮在0.005～1.00μg/mL范围内线性良好,线性相关系数(r)为0.9990。该方法对唑草酮的最小检出量为1.0×10-12g,唑草酮在甘蔗植株和土样的最低检测浓度均为0.001 mg/kg,对甘蔗及其土壤空白样本的平均添加回收率为88.59%～102.74%,相对标准偏差为1.77%～5.39%。该方法符合农药残留分析的要求,具有操作简单、净化分离效果好、检测灵敏度高特点。

To establish analytical method for determining carfentrazone-ethyl residues in the sugarcane and soil sample,carfentrazone-ethyl was extracted from the soil and sugarcane sample with methanol-water（4∶ 1,volume ratio）,and the extract was partitioned with petroleum ether-dichloromethane（4∶ 1,volume ratio）.Then the upper layer was concentrated and cleaned up on a column of Florisil.Finally carfentrazone-ethyl was separated from other interfering components through capillary gas chromatographic column and was detected by μECD.The result showed that the linearities of carfentrazone-ethyl was in the range of 0.005 to 1.0 μg/mL with the correlation coefficient of 0.9990.The lowest detection limit for carfentrazone-ethyl was 1.0×10-12 g.The lowest detectable concentration in sugarcane and soil was 0.001 mg/kg.The average recovery rate and relative standard deviation of this method were 88.59 %-102.74 % and 1.77 %-5.39 % respectively.This method was simple,sensitive and suitable for residue analysis of carfentrazone-ethyl.