LAUSR

ABSTRACT The determination of rosiglitazone in dietary supplements by direct analysis in real-time mass spectrometry normally provides low repeatability. The [M+H]+ signal sharply decreased in the presence of strong-base and weak-acid ionic compounds because rosiglitazone decomposition occurred due to the hydrolysis of strong-base and weak-acid anions. The repeatability was improved and the influence of ionic compounds was minimized by the use of pioglitazone as an internal standard. Orbitrap mass spectrometry was used to provide high resolution in which isotopic interferences from M + 1 of pioglitazone upon M of rosiglitazone were eliminated. This approach was used to determine rosiglitazone in tablet and dietary supplements in 1 min per sample.