| Sulfonylurea herbicide is widely used in the management of weeds.This herbicide is very soluble in water, easy to cause water pollution, residue on succeeding crops are sensitive to cause great harm in the soil, but also have certain stimulation to the skin, eyes and mucous membranes. Because this kind of material content is very low in environmental water samples, in order to improve sensitivity and accuracy of the detection, we also need to test the necessary sample pretreatment before operation.This paper selects the use of a wide range of some sulfonylurea compounds in our country as the target analyte, establish an analysis method for determination of its content in environmental water.Using liquid liquid extraction(LLE), solid phase extraction column(SPE) and magnetic solid phase extraction(MSPE) as a sample preparation method, high performance liquid chromatography with UV detection for separation and detection means, has carried on the systematic study.The main contents are as follows:(1)An analytical method of liquid-liquid extraction of 10 sulfonylurea herbicides in environmental water samples by high performance liquid chromatography was developed.Under the optimal chromatographic conditions, we investigated the extraction agent and volume, extraction times, extraction time and standing time,p H value and salinity of sample.The method was linear in the range of 0.02~10.0mg/L,the detection limit between 0.017~0.063μg/L, can meet the EU "water law"(75/440/EEC) of pesticide limits specified in the requirements of less than 1-5μg/L.The surface water of Qingdao Jihongtan reservoir is studied in precision and accuracy of inspection, the relative standard deviation(RSD) is less than 14.1%, standard addition recovery rate is between 73.0%~104.6%.This method does not need complicated equipment, simple operation, easy to popularize.(2)Solid phase extraction column was established for determination of 10 sulfonylurea herbicides in environmental water samples by high performance liquid chromatography.Using C18 solid phase extraction column, eluent type and volume, p H value of sample and salinity of solid phase extraction conditions were optimized.The method was linear in the range of 0.02~10.0mg/L, the detection limit between0.014~0.032 μg/L.Precision and accuracy of inspection was carried out on the surface water, the relative standard deviation(RSD) is less than 13.0%, standard addition recovery rate is between 75.6%~110.6%.The method is better than the liquid liquid extraction with solvent volume,and multiple sample can be operated at the same time.(3)An analytical method of magnetic solid phase extraction of 6 sulfonylurea herbicides in environmental water samples by high performance liquid chromatography was developed. The magnetic multi-walled carbon nanotubes was homemade, and was conducted by the use of X- ray diffraction. To study the influence of magnetic solid phase extraction efficiency,we investigated the effects of adsorbent dosage,p H value of sample, salt concentration, extraction time, the type and amount of eluent.And determined the optimum extraction conditions.The method was linear in the range of 0.02~10.0 mg/L, the detection limit between 0.001μg/L~0.004 μg/L.Precision and accuracy of inspection was carried out on the surface water, the relative standard deviation(RSD) is less than 9.8%, standard addition recovery rate is between84.9%~106.9%.Precision and accuracy of inspection was carried out on the tap water,the relative standard deviation(RSD) is less than 11.3%, standard addition recovery rate is between 78.2%~105.4%.The method does not need complex equipment and has the advantages of simple operation, time saving, high sensitivity. Can be used in the detection of environmental water samples of sulfonylurea herbicides. |
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