Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 5, 2002
Publication Date: September 22, 2002
Citation: LEHOTAY, S.J., SCHNEIDER, M.J., FAGERQUIST, C.K., LIGHTFIELD, A.R. APPROACHES AND RECOMMENDATIONS TO VALIDATE MS CONFIRMATION CRITERIA FOR VETERINARY DRUG RESIDUES IN FOOD. 116TH AOAC INTERNATIONAL ANNUAL MEETING. ABSTRACT. 2002. P. 80. Technical Abstract: All confirmation criteria for mass spectrometry (MS) to date have been devised using minimal data or arbitrary criteria set by the analysts. In the regulatory arena for agrochemical residues, general guidelines for needing at least 3 ions of a given ratio interval to make a confirmation originated from an experiment involving a single drug in 1978 using a very small database. No organization has yet to provide statistically validated minimal criteria to be achieved for an analyst to make a confirmation of chemicals using MS. Ultimately, the analyst must use their knowledge, experience, and common sense to make an assertion that indeed, a positive or negative finding has been made. We believe that just as quantitative analysis requires validation to demonstrate the capabilities and limitations of a method, qualitative analysis by MS should also be validated to establish confirmation criteria and determine method performance. The ion ratios should be measured to define an ion ratio interval for confirmation, and multiple blank matrices should be used to assess possible interferences. Also, depending on the importance of the analysis and need for the data, we propose that blind analysis of proficiency check samples be used to determine actual rates of false positives and negatives.