The fundamental goal in analytical chemistry is to answer the question: "What is in the sample and how much?" The degree of certainty needed in the result depends on the stakes involved. Due to high stakes in food safety, the economics of trade, and quality of the environment, many regulatory monitoring labs often use the most advanced chromatography and mass spectrometry tools commercially available. In terms of quantification, extensive method validation protocols and laboratory accreditation practices have evolved to meet strict quality assurance and control standards. However, the theory and practice of qualitative analysis is less developed, despite the fundamental importance of achieving a result for the correct analyte. Many regulators and chemists simply rely on technology and make generalizations and arbitrary rules without empirical evaluations of the rates of false positives and negatives in an analysis.
A growing trend in the field is to seek ways to validate methods qualitatively as well as quantitatively, but traditional qualitative validation protocols are too demanding in practice. In this presentation, aspects of the past, present, and future in qualitative analysis primarily using mass spectrometry for high stakes regulatory food monitoring will be discussed. Many real-world examples of pitfalls and past mistakes will be given, distinctive terms will be defined, current identification criteria will be described, and practical validation protocols to assess rates of false positives and negatives will be proposed, which can be incorporated into novel analytical approaches such as ambient mass spectrometry and flow-injection analysis without traditional use of chromatography.
Steve Lehotay received a B.S. in Chemistry (1987) and a Ph.D. in Analytical Chemistry (1992) from the University of Florida. He has authored/co-authored >115 scientific publications and >190 meeting abstracts. He has received numerous awards, including the Journal of Chromatography A Top Cited Article 2010-2011 (shared, 2012), ACS Division of Agrochemicals Award for Innovation in Chemistry of Agriculture (2012), AOAC International Harvey W. Wiley Award (2011), ARS Outstanding Efforts in Technology Transfer Award (shared, 2009) UCT Excellence in SPE Award (shared, 2007), AOAC International Study Director of the Year (2007) and AOAC International Collaborative Study of the Year (2007).
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