HPLC Method for Quantification of Caffeine and Its Three Major Metabolites in Human Plasma Using Fetal Bovine Serum Matrix to Evaluate Prenatal Drug Exposure

Figure 2

Representative chromatograms of FBS blank (a), FBS + IS (b), FBS spiked with caffeine and metabolites at all calibration curve levels lower (0.1 μg/mL) and upper (40.0 μg/mL) (c), and zoomed-in view showing the lower limit of quantification (d); plasma obtained from a mother volunteer and her child (e) without caffeine and metabolites (volunteer 3); and plasma obtained from a mother volunteer and a pair of her twins T1 and T2 (e) containing caffeine and metabolites (volunteer 5). Theb: theobromine (RT 3.8 min), Par: paraxanthine (RT 4.8 min), Theo: theophylline (RT 5.5 min), IS: 7-β-(hydroxyethyl)theophylline (RT 7.0 min), and caffeine (RT 12 min). RT: retention time.

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