Proposed quantitative and alphanumeric metabolite identification metrics

Abstract

In June, 2014 the Metabolomics Identification Task Group published an article entitled ‘‘Metabolite identification: are you sure? And how do your peers gauge your confidence?’’(Creek et al. 2014). This article invited additional feedback and we would like to respond publically with a few more details regarding accurate reporting of metabolite identifications. The community consensus is that the leading challenge of metabolomics is the chemically accurate identification of large numbers of metabolites observed in various nontargeted profiling techniques. Metabolite identification is critically important because it provides the fundamental biological and biochemical context to the metabolomics data. However, accurate structure identification requires significant effort which increases dramatically with the increased scale of nontargeted metabolomics and typically involves hundreds or thousands of metabolites per analysis. The metabolomics community has been discussing the challenges of metabolite identification and minimum reporting criteria for some time, and the Chemical Analysis Working Group of the Metabolomics Standards Initiative proposed some basic guidelines in 2007 (Sumner et al. 2007). This group reported four identification classes as summarized below.