LC-MS analysis reveals that Slr1334 metabolizes Frc-1,6-BP into a molecule of identical mass that is not degraded by Frc-1,6-BP-aldolase. Analysis of the products of the reaction without (A) and with Slr1334 (B) via LC/MS. Shown are the base peak chromatograms (BPC) in the mass range (M-H)- m/z = 79–1,601 (gray) and the extracted ion chromatograms (EIC) based on the exact masses of NAD+ (M-H)− = 662.101 m/z (light blue), NADH (M-H)− = 664.117 m/z (red), Glycerol 3-P (M-H)− = 171.006 m/z (yellow), Glc-1,6-BP/Frc-1,6-BP (M-H)− = 338.988 m/z (purple). The presence of the NAD+ (blue) and Glycerol-3P (yellow) peaks in (B) shows that Frc-1,6-BP was not fully metabolized into Glc-1,6-BP. Magnification and adjustment of the graphs in (A) and (B) is clear evidence of the absence (C) or formation (D) of Glc-1,6-BP.