Kashyap Sanjay M, Pandya Girish H, Kondawar Vivek K, Gabhane Sanjay S
National Environmental Engineering Research Institute, Instrumentation Division, 20 Nehru Marg, Nagpur 440002, Maharashtra, India.
J Chromatogr Sci. 2005 Feb;43(2):81-6. doi: 10.1093/chromsci/43.2.81.
The 2,4-dichlorophenoxy acetic acid (2,4-D) is used as a systemic herbicide to control broadleaf weeds in wheat, corn, range land/pasture land, sorghum, and barley. In this study, a fast and efficient method is developed by selection of modified extraction apparatus and high-performance liquid chromatography (HPLC)-UV conditions for the determination of 2,4-D in soil samples. The method is applied to the study of soil samples collected from the agricultural field. The herbicide is extracted from soil samples by acetonitrile in a modified Soxhlet apparatus. The advantages of the apparatus are that it uses small volume of organic solvent, reduced time of extraction, and better recovery of the analyte. The extract is filtered using a very fine microfiber paper. The total extract is concentrated in a rotatory evaporator, dried under ultrahigh pure N2, and finally reconstituted in 1 mL of acetonitrile. HPLC-UV at 228 nm is used for analysis. The herbicide is identified and quantitated using the HPLC system. The method is validated by the analysis of spiked soil samples. Recoveries obtained varied from 85% to 100% for spiked soil samples. The limit of quantitation (LOQ) and the limit of detection (LOD) are 0.010 and 0.005 parts per million (ppm), respectively, for spiked soil samples. The LOQ and LOD are 0.006 and 0.003 ppm for unspiked soil samples. The measured concentrations of 2,4-D in spiked soil samples are between 0.010 and 0.020 ppm with an average of 0.016 +/- 0.003 ppm. For unspiked soil samples it is between 0.006 ppm and 0.012 ppm with an average of 0.009 +/- 0.002 ppm. The measured concentrations of 2,4-D in soil samples are generally low and do not exceed the regulatory agencies guidelines.
2,4-二氯苯氧乙酸（2,4-D）用作内吸性除草剂，用于防治小麦、玉米、牧场/牧草地、高粱和大麦中的阔叶杂草。在本研究中，通过选择改进的萃取装置和高效液相色谱（HPLC）-紫外检测条件，开发了一种快速有效的方法来测定土壤样品中的2,4-D。该方法应用于对从农田采集的土壤样品的研究。除草剂在改进的索氏提取器中用乙腈从土壤样品中萃取。该装置的优点是使用少量有机溶剂、缩短萃取时间且分析物回收率更高。萃取液用非常细的微纤维滤纸过滤。总萃取液在旋转蒸发仪中浓缩，在超纯氮气下干燥，最后用1 mL乙腈复溶。使用228 nm波长的HPLC-紫外检测进行分析。使用HPLC系统对除草剂进行鉴定和定量。通过对加标土壤样品的分析验证了该方法。加标土壤样品的回收率在85%至100%之间。加标土壤样品的定量限（LOQ）和检测限（LOD）分别为百万分之0.010和0.005。未加标土壤样品的LOQ和LOD分别为百万分之0.006和0.003。加标土壤样品中2,4-D的测定浓度在0.010至0.020 ppm之间，平均为0.016±0.003 ppm。未加标土壤样品中其浓度在0.006 ppm至0.012 ppm之间，平均为0.009±0.002 ppm。土壤样品中2,4-D的测定浓度一般较低，未超过监管机构的指导标准。
