Abstract : Cleaning validation (CV) is a Good Manufacturing Practices (GMP) requirement in the manufacturing of drug substances and drug products. High performance liquid chromatography (HPLC) with UV detection is a common choice for cleaning verification studies for most drugs at sensitivity levels (limits of quantitation or LOQ) of ∼20 to 50 ng/mL. For highly potent drugs, CV methods to reach sensitivity levels of low ng/mL can be implemented using UV detection with a long-pathlength UV flow cell and/or mass spectrometric (MS) detection. The sensitivity of an ultra-high pressure liquid chromatography (UHPLC)-MS method presented herein using a single quadrupole mass spectrometer (SQMS) provides even lower LOQ of ∼0.5 ng/mL. In addition, larger injection volumes can further lower LOQs. In this study, we show a 2-minute generic cleaning verification method having an LOQ range of 0.5 ng/mL to 1000 ng/mL for 5 model drug compounds. This generic cleaning verification assay method can also be adapted to many different drugs with minimum efforts in method development, qualification, and transfer. In this paper, we also demonstrate the identification of unknown compounds using a user-supplemented Mass Spectral Search Program. Copyright © 2015 CompareNetworks, Inc. All rights reserved.