Study On Determination Of Herbicides And Fungicides In Environmental Water By Aqueous Two-Phase System Extraction-High Performance Liquid Chromatography

In some agricultural production and animal husbandry,a large number of pesticides are needed,and herbicides and fungicides are two of them.Pesticides have good water solubility and stable chemical structure,but they also cause them to remain in the water environment for a long time.When the herbicides and fungicides left in the environment reach a certain concentration,they will Harmful to the health of animals and plants and humans.Therefore,thereisanurgentneedtoestablishaneconomical,environmentally-friendly,and highly efficient sample preparation method to detect residual herbicides and fungicides in environmental water.In recent years,Aqueous two-phase systems?ATPS?,a low-cost,easy-to-use sample preparation method,has attracted many academics at home and abroad.Compared with traditional extraction techniques,the two-phase extraction technology has many advantages.The two phases of the two aqueous phases contain sufficient water to operate under mild conditions,thus avoiding the denaturation of certain substances.Inactivation,while cost-effective and flexible operating mode allows it to be produced on a large scale.In this paper,an organic solvent/inorganic salt aqueous two-phase system and a glycol/inorganic salt aqueous two-phase system were established to study the enrichment and separation of herbicides and fungicides in environmental water samples,and the related influencing factors were discussed.The effect of analyte extraction rate.The specific research contents and experimental results of this paper are listed below:1.The hazards of pesticides and some common sample pretreatment techniques were introduced.The historical background,extraction principle,system types,influencing factors and application prospects of the two-phase system were introduced.2.A method for simultaneous determination of 6 triazine herbicides in environmental water samples by acetonitrile/inorganic salt aqueous two-phase microextraction combined with high performance liquid chromatography?HPLC?was established.Various experimental parameters including the types and volumes of organic solvent and the volume of acetonitrile,the type and amount of inorganic salt,the pH value of the sample solution and the ultrasound extraction time were optimized.The results showed that:450?L acetonitrile was used as the extractant,2.80g?NH₄?₂SO₄ was used as the phase separation salt,and ultrasonic extraction was carried out for 10 min.The triazine herbicide was extracted in the water sample with neutral pH.Under the optimal extraction conditions,the detection limits of six triazine herbicides were 0.16⁰.28?g/L.The actual water sample was tested by this method,and satisfactory results were obtained.3.The two alcohol/inorganic salt aqueous two-phase system was developed for separation and enrichment of 6 triazole fungicides in environmental water samples combined with high performance liquid chromatography?HPLC?for analysis and determination.The influence factors of the composition and ratio of two small molecule alcohol,salt type and concentration,pH value,ultrasound extraction time and temperature were optimized to improve the extraction efficiency.The results showed that the system consisted of n-propanol:isopropanol?v:v mL/mL?of 0.02:0.04,?NH₄?₂SO₄ concentration?w/v?of 64%,the pH value was 6⁷,the ultrasound extraction time was 15 min and temperature was 25±0.5?.The triazole fungicide obtained a good linear range in the binary aqueous two-phase extraction system with coefficient of determination?R²??0.9986,and the detection limit of the method was 1.67¹2.96?g/L.The actual water sample was tested by this method,and satisfactory results were obtained.