Several fundamental requirements must be met so that NMR-based metabolomics can be formally adopted into environmental monitoring and chemical risk assessment. Here we report an intercomparison exercise which has evaluated the accuracy, precision and efficacy of 1H NMR metabolomics for environmental research. It focuses on laboratory practice that follows sample collection and metabolite extraction, specifically the final stages of sample preparation, NMR data collection (500, 600 and 800 MHz), data processing (custom-written and commercial software) and multivariate analysis. Seven laboratories have participated from the USA, Canada, UK and Australia, generating a total of ten datasets. Phase 1 comprised the analysis of synthetic metabolite mixtures, while Phase 2 investigated European flounder (Platichthys flesus) liver extracts from clean and contaminated sites. Overall, the precision and accuracy of the participating laboratories was good. Principal components analyses (PCA) of the individual datasets yielded ten highly similar scores plots for the synthetic mixtures, with a similar result for the liver extracts. Furthermore, the same metabolic biomarkers that discriminated fish from clean and contaminated sites were discovered by all the laboratories. PCAs of the combined datasets showed excellent clustering of the repeat analyses. These results demonstrate that NMR-based metabolomics can generate data that are sufficiently reproducible between laboratories to support its continued evaluation for regulatory environmental studies.
Citation: Environmental Science & Technology
Pub Type: Journals
Metabolomics, NMR, Intercomparison, PCA, Environmental