Wang Xuedong, Zhao Xinna, Liu Xiujuan, Li Yanyan, Fu Lingyan, Hu Jia, Huang Changjiang
School of Environmental Science and Public Health, Wenzhou Medical College, Wenzhou 325035, China.
Anal Chim Acta. 2008 Jul 14;620(1-2):162-9. doi: 10.1016/j.aca.2008.05.021. Epub 2008 May 20.
In this study, a new method was developed for analyzing malathion, cypermethrin and lambda-cyhalothrin from soil samples by using homogeneous liquid-liquid extraction (HLLE) and gas chromatography with electron capture detector (GC-ECD). Acetone was used as extraction solvent for the extraction of target pesticides from soil samples. When the extraction process was finished, the target analytes in the extraction solvent were rapidly transferred from the acetone extract to carbon tetrachloride, using HLLE. Under the optimum conditions, linearity was obtained in the range of 0.05-40 microg kg(-1) for malathion, 0.04-10 microg kg(-1) for lambda-cyhalothrin and 0.05-50 microg kg(-1) for cypermethrin, respectively. Coefficients of correlation (r(2)) ranged from 0.9993 to 0.9998. The repeatability was carried out by spiking soil samples at concentration levels of 2.5 microg kg(-1) for lambda-cyhalothrin, and 10 microg kg(-1) for malathion and cypermethrin, respectively. The relative standard deviations (RSDs) varied between 2.3 and 9.6% (n=3). The limits of detection (LODs), based on signal-to-noise ratio (S/N) of 3, varied between 0.01 and 0.04 microg kg(-1). The relative recoveries of three pesticides from soil A1, A2 and A3 at spiking levels of 2.5, 5 and 10 microg kg(-1) were in the range of 82.20-91.60%, 88.90-110.5% and 77.10-98.50%, respectively. In conclusion, the proposed method can be successfully applied for the determination of target pesticide residues in real soil samples.
在本研究中，开发了一种新方法，通过使用均相液液萃取（HLLE）和带有电子捕获检测器（GC-ECD）的气相色谱法，分析土壤样品中的马拉硫磷、氯氰菊酯和高效氯氟氰菊酯。使用丙酮作为萃取溶剂从土壤样品中萃取目标农药。萃取过程完成后，利用均相液液萃取将萃取溶剂中的目标分析物从丙酮萃取液快速转移至四氯化碳中。在最佳条件下，马拉硫磷的线性范围为0.05 - 40 μg kg⁻¹，高效氯氟氰菊酯为0.04 - 10 μg kg⁻¹，氯氰菊酯为0.05 - 50 μg kg⁻¹。相关系数（r²）范围为0.9993至0.9998。重复性实验分别在高效氯氟氰菊酯浓度水平为2.5 μg kg⁻¹、马拉硫磷和氯氰菊酯浓度水平为10 μg kg⁻¹的加标土壤样品上进行。相对标准偏差（RSDs）在2.3%至9.6%之间（n = 3）。基于信噪比（S/N）为3的检测限（LODs）在0.01至0.04 μg kg⁻¹之间。在加标水平为2.5、5和10 μg kg⁻¹时，三种农药从土壤A1、A2和A3中的相对回收率分别在82.20% - 91.60%、88.90% - 110.5%和77.10% - 98.50%范围内。总之，所提出的方法可成功应用于实际土壤样品中目标农药残留的测定。
