Measurement Uncertainty Associated with Sample Processing of Oranges and Tomatoes for Pesticide Residue Analysis

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• 作者：Richard J. Fussell ; Michael T. Hetmanski ; Roy Macarthur ; Dawn Findlay ; Frankie Smith ; &Aacute ; rpad Ambrus ; Peter Josef Brodesser
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2007
• 出版时间：February 21, 2007
• 年：2007
• 卷：55
• 期：4
• 页码：1062 - 1070
• 全文大小：232K
• 年卷期：v.55,no.4(February 21, 2007)
• ISSN：1520-5118

文摘

The homogeneity of analytical samples and the stability of pesticides during the sample processingof oranges and tomatoes were evaluated. The mean concentrations of ¹⁴C-labeled chlorpyrifos inanalytical portions (subsamples) after processing show that homogeneity is dependent on sampletype as well as the processing procedure. The homogeneity of analytical samples of tomatoesprocessed cryogenically was much better than those processed at ambient temperature. For tomatoes,the minimum analytical portion masses required for between-analytical portion variation of <0.3 Howere 110 and 5 g for processing at ambient and cryogenic temperatures, respectively. Results fororange showed that analytical portion sizes of 5 g provided sufficient homogeneity from both sampleprocessing procedures. Assessments of pesticide stability demonstrated that most were relativelystable during processing at either ambient or cryogenic temperatures. However, some pesticides,including dichlofluanid, chlorothalonil, tolylfluanid, and dicloran, appeared to suffer much greater losses(>20%) during processing at ambient temperature. For these analytes, loss is interpreted as chemicaldegradation.