Figure 2

Average percentages of false positives and false negatives. A standard mixture containing 13 metabolites was divided in 10 aliquots and analysed by GC-MS. Each sample was then processed by MetaBox and AMDIS using match factors of 70, 80 and 90. Shown are the average percentages, plus error bars representing two times the standard error, of false positives and false negatives produced by each tool. False positives are compounds that are misidentified, while false negatives are unidentified compounds that are present in the standard mixtures.