|An HIV-positive patient population was sampled from The Johns Hopkins Hospital emergency room as part of an HIV incidence study. Blood was analyzed for presence of opiates, cocaine, amphetamines and their metabolites. Screening was performed with liquid chromatography-ultra high resolution (UHRAM ) accurate mass spectrometry and confirmation was performed using liquid chromatography–triple quadrupole mass spectrometry. Of 100 samples analyzed, 36 tested positive by the screening method. 100% of these samples testing positive by the screening method were also found to be positive by the confirmatory method. Retrospective analysis of UHRAM data was performed to identify whether drugs other than those targeted are present in samples.