Measurement uncertainty associated with sample processing of oranges and tomatoes for pesticide residue analysis

Richard J. Fussell, Michael T. Hetmanski, Roy Macarthur, Dawn Findlay, Franke Smith, Árpad Ambrus, Peter Josef Brodesser

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

The homogeneity of analytical samples and the stability of pesticides during the sample processing of oranges and tomatoes were evaluated. The mean concentrations of 14C-labeled chlorpyrifos in analytical portions (subsamples) after processing show that homogeneity is dependent on sample type as well as the processing procedure. The homogeneity of analytical samples of tomatoes processed 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 Ho were 110 and 5 g for processing at ambient and cryogenic temperatures, respectively. Results for orange showed that analytical portion sizes of 5 g provided sufficient homogeneity from both sample processing procedures. Assessments of pesticide stability demonstrated that most were relatively stable 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 chemical degradation.

Original languageEnglish
Pages (from-to)1062-1070
Number of pages9
JournalJournal of Agricultural and Food Chemistry
Volume55
Issue number4
DOIs
Publication statusPublished - Feb 21 2007

Keywords

  • Homogeneity
  • Oranges
  • Pesticide stability
  • Sample processing
  • Tomatoes
  • Uncertainty

ASJC Scopus subject areas

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

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