Research On The Detection Method Of The Residue Of Pentachlorophenol Sodium In Fresh Eggs

Sodium pentachlorophenol was an organochlorine pesticide,which degraded slowly in natural environment.It could enter the poultry body through the way such as feed and accumulate in the poultry body,thus remaining in the egg food,which was very harmful to human body.At present,in the national standards of China,there were only detection methods for the residues of pentachlorophenol?and its sodium salt?in meat and water.As the ingredients of raw materials of meat products and fresh eggs were different from each other,and the ingredients of fresh eggs were complex,the background interfered greatly with the test results.Therefore,the existing two kinds of national standards were not fully applicable to the detection of fresh eggs.Therefore,it was urgent to establish the detection method of sodium pentachlorophenol in fresh eggs.The main research conclusions were as follows:?1?The optimized extraction conditions of liquid-liquid extraction were:The addition amount of trichloroacetic acid was 3m L,the ratio of the extract solution was 9:1,the centrifugal time was 4min and the centrifugal speed was 10000rpm.The recovery rate of the labeled samples was 78.56±1.02%,which was closed to the predicted result of response surface software?78.96%?.?2?Solid phase extraction was used to purify and concentrate the samples.By comparison,SLC solid phase extraction column had the highest recovery rate.The amount of acetonitrile eluent added was 4m L.?3?The optimal derivative conditions of sodium pentachlorophenol in fresh eggs through single factor and orthogonal experiment were as follows:Derivative liquid ratio(V_{Acetic anhydride}:V _Pyridine)was1:1,the time derivative was 15 min,a derivative of temperature was 60?.Under these conditions,the recovery rate of sodium pentachlorophenol in fresh eggs was measured as 76.9±0.95%.?4?In the process of gas chromatography analysis,TG-5MS capillary chromatographic column was selected:Separation of components was performed at 30m x 0.25mm?inner diameter?x 0.25mm?film thickness?.Appropriate heating processes ware as follows:Initial column temperature was 80?,and kept the temperature for 2 minutes,and then increased to 250?with a speed of 10?/min,then kept it for 5 min,again increased to 290?with a speed of 10?/min,and the temperature was kept for 4 min.In the process of mass spectrum end analysis,the ion range m/z of 40?320amu was selected for qualitatively analyzing of residual pentachlorophenylacetate in the solution.The presence of pentachlorophenylacetate was determined by extraction of characteristic ion chromatogram,and the qualitative time of pentachlorophenylacetate was 16.57min.The characteristic ions of 266amu were selected as quantitative ions.264amu,268amu and 308amu were selected as qualitative ions.?5?When the residual amount of sodium pentachlorophenol in fresh eggs was within the range of 10ng/m L?200 ng/m L,the curve had good linearity.The linear equation was:Y=-7254.4+1041.36X?Correlation coefficient r²=0.9994.When the reagent blank test was conducted,when the retention time was16.57min,the baseline was flat and there was no interference peak,indicating that the reagent had no interference with the test results.The recycling rate of the samples is between 73.2%and 88.6%,and the precision is 1.42%to 4.18%,meeting the requirements of national standards.The quality control of sodium pentachlorophenol was analyzed by laboratory quality control.The quality control chart obtained meets the requirements of reliability test,indicating that the test method was accurate and reliable.