Within drug development, the quantitation of drug levels within the systemic circulation and target tissues can provide insight into tolerance and / or efficacy. For small molecules the mainstay for quantitative analysis is LC-MS/MS. 5-azacytidine has been used in the treatment of lung cancer, and for years the nucleosidic nature of 5-azacytidine resulted in significant interference with parent compound’s MRM mass transitions. In order to solve this the Lovelace bioanalytical team utilized a novel approach which enabled quantification from plasma and multiple tissues (lung, brain, and liver) with greater sensitivity than published methods. These results are being presented at the 67th ASMS Conference on Mass Spectrometry and Allied Topics, on Thursday, June 6th (ThP 769). If you are attending ASMS this year, please visit the poster with questions or reach out to the Lovelace bioanalytical scientists via our website.