Study Of The Analysis Methods Of Isoproturon,Prometryne And Fluroxypyr Residues

Isoproturon(IPU), prometryne(PRO) and fluroxypyr(FLX) are herbicides that all are organic compounds. Isoproturon is a substituted phenylurea selective herbicide and prometryne is a selective herbicide of the s-triazine chemical family and fluroxypyr is an oxyacetic acid herbicides. These three herbicides are extensively used for controlling of annual grasses and broadleaved weeds in modern agriculture. However, they are toxic to environment and the questions such as the safe of agriculture products and the water and soil pollution have raised widespread concern. Hence, there is a need to develop a sensitive and highly efficient method to determinate the residue quantity of isoproturon, prometryne and fluroxypyr together. Amounts of reports about the residues of isoproturon or prometryne or fluroxypyr in single-agent detection were studied at home and abroad. Unfortunately, little research has been conducted on the simultaneous detection of all the three pesticides. In this study, two residues analysis methods for these three herbicides were provided.Firstly, liquid-liquid extraction (LLE) and solid phase extraction (SPE) for simultaneous determination of isoproturon, prometryne and fluroxypyr in soil, water and cabbage by high performance liquid chromatography with ultraviolet detector were developed. Residues in water were extracted and pre-concentrated and purified by the SPE-C18column. Soil sample were extracted with the solution of methanol and water (3:1, v/v) by shake and purified by liquid-liquid extraction (LLE). The residues of cabbage were extracted with acetonitrile by shake and purified by SPE-Florisil column. The correlation coefficients of isoproturon, prometryne and fluroxypyr were0.9999,1.0000and0.9999respectively, and their calibration curves were liner in the range of0.05～10.0mg L-1. The spiked recoveries were in the rang of86.7%-99.1%for water sample,83.9%-93.4%for soil sample,88.1%-97.4%for cabbage, with relative standard deviations(RSDs) of0.9%-6.6%,1.2%-8.0%,3.6%-7.9%respectively.At the same time, a new and efficient analytical methodology named cloud point extraction (CPE) coupled with high performance liquid chromatography (CPE-HPLC) was developed for determination the residues of isoproturon and prometryne in soil, water and cabbage. The non-ionic surfactant poly ethylene glycol6000(PEG-6000) was chosen as the extraction solvent. Multiple experimental conditions affecting CPE efficiency including surfactant type and concentration, equilibration time and temperature and salt concentration were investigated. Meanwhile, the Langmuir equation was used to fit the quantity of PEG-6000. At last, the CPE conditions were optimized as follows:2.4%PEG-6000(w/v),11%Na2SO4(w/v) and heat-assisted at50℃for25min. The spiked recoveries were in the rang of85.4%～90.6%for water sample,84.4%～92.7%for soil sample,84.4%～92.1%for cabbage, with relative standard deviations(RSDs) of0.8%～6.2%,2.0%～6.0%,2.0%～7.2%respectively.