ALBERT

Description:    A metrological approach is used for investigating multi-component out-of-specification (OOS) test results of pesticide residues concentration in tomatoes. As a case study, 169 test results were obtained in Israel in 2009. Five of the test results were OOS test results exceeding the national legal maximum residue limits ( MRL ). Only one of them was classified definitely (with more than 0.99 confidence) as caused by a farmer’s/producer’s problem. The other four OOS test results were probably metrologically related, i.e., compatible with MRL when considering the measurement uncertainty associated with the test results. A new parameter—the ratio of a test result to MRL —was proposed for analysis of tomatoes monitoring multi-residue data as a common statistical sample from the same population for different pesticide residues. Weibull distribution was found adequate for modeling the empirical distribution of the parameter values. Probability of future OOS test results was estimated, and global risks of farmer/producer and consumer/buyer were evaluated. Acceptance limits for the test results, such as “warning and action lines” in quality control charts, were calculated by taking into account the measurement uncertainties. Content Type Journal Article Pages 1-7 DOI 10.1007/s00769-011-0780-3 Authors Ilya Kuselman, The National Physical Laboratory of Israel (INPL), Givat Ram, 91904 Jerusalem, Israel Paulina Goldshlag, Laboratory for Pesticide Residue Analysis, Plant Protection and Inspection Services (PPIS), P.O.Box 78, 50250 Bet-Dagan, Israel Francesca Pennecchi, Istituto Nazionale di Ricerca Metrologica (INRIM), 73 Strada delle Cacce, 10135 Turin, Italy Cathy Burns, Food and Drug Administration (FDA), 6th Ave and Kipling St, DFC-Bldg 20, Denver, CO 80225, USA Journal Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement Online ISSN 1432-0517 Print ISSN 0949-1775