Figure 2
Analyte confirmation by ion intensity ratio comparison of dexamethasone in a post-race plasma with that spiked in blank equine plasma. Product ion intensity ratio of dexamethasone in the test sample (upper panel) compared with calibrator (lower panel, left) and with its isomer, betamethasone (lower panel, right) spiked in blank plasma, extracted and analyzed to ensure that the 3 criteria (similarity in product ion intensity ratio, similarity in 3 ion transitions and in tR) established for confirmation of the presence of dexamethasone in the test sample were satisfied. The difference in ion intensity ratio between the sample and the calibrator was < 20%.