Fig 1.
A. Metformin and B. metformin-D6 fragmentation ion scans. Y-axis is Relative intensity (cps); X-axis is mass-to-charge (m/z). Red arrow indicates peak for m/z 60.2, pink arrow indicates peak for m/z 71.2.
Fig 2.
Variation of Metformin chromatography by A. Metformin tautomerization in terms of proton movement; B. Representative Chromatographs before and after optimization from left to right: plasma, brain, muscle, liver, and kidney. For each graph, Y-axis: Intensity abundance (cps) and X-axis: acquisition time (min).
Fig 3.
Representative MRM LC-MS/MS overlaid chromatogram of metformin at a lower limit of quantitation concentration and representative individual matrix blank injection after ULOQ.
Each individual tissue was represented by colors- green-plasma; blue-brain; dark green-muscle; brown-liver; red-kidney; black-mobile phase A. Y-axis: Intensity abundance (cps) and X-axis: acquisition time (min).
Table 1.
Intra-day and inter-day precision and accuracy of the method in plasma and tissue homogenate spiked with metformin.
Table 2.
Matrix effect (% MF) and recovery (%) of QC samples (n = 6) for metformin in spiked mouse plasma.
Table 3.
Metformin concentrations in plasma, brain, liver, kidney, and muscle after 7 or 30 days of metformin treatment in male and female mice.
Fig 4.
Linear regression of metformin levels between plasma and different organs (n = 24).
Plasma and A. brain, B. liver, C. kidney, and D. muscle. Y-axis units are ng/g, and X-axis units are ng/ml.
Table 4.
Comparison of metformin assessment methods using LC-MS/MS.