Evaluation of the Uncertainty of the Residue of Carbendazim in Cucumber by High Performance Liquid Chromatography
This paper establishes an uncertainty evaluation method for determining the amount of carbendazim in cucumber.Carbendazim is extracted from cucumber samples using acetonitrile,salted out and purified by magnesium sulfate,separated by reversed-phase ion-pair reagent chromatography,and determined at 275 nm wavelength.The retention time is qualitative and the external standard method is quantitative.The mathematical model of the experimental process is established and the source of uncertainty is analyzed to determine the main component of uncertainty,and the relative synthetic standards uncertainty and expansion uncertainty are calculated.The results show that when the amount of residue of the spirit is 1.98 mg·kg-1,it is estimated at a normal distribution.When the probability of confidence is 95%,and the expansion uncertainty is 0.10 mg·kg-1 when the factor k=2.The uncertainty introduced into the standard solution and its preparation process and the uncertainty introduced into the sample volume determination process have a great influence on the test result.Through the assessment of measurement uncertainty,it is necessary to operate strictly in accordance with the standard specifications to reduce human errors and ensure the accuracy and reliability of the test results.
high performance liquid chromatographycucumbercarbendazimuncertainty
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