Figure 1.

Exhaled breath (EB) samples tested by reversed‐phase liquid chromatography/tandem mass spectrometry for 12 model compounds including anabolic agents, hormone and metabolic modulators, stimulants, and beta‐blockers: (A) blank EB specimen containing only the internal standards D₃‐testosterone, D₃‐meldonium, (S)‐2‐aminooctane, and D₇‐propranolol. Y‐axes are normalized to the abundance of the corresponding spiked specimen shown under (B), which illustrates the results of an EB sample fortified with 500 pg of each target analyte plus ISTDs