Accurate mass measurements of 20 drugs were conducted using MassWorks software on a TSQ Quantum Ultra mass spectrometer. All Q1 scan mass spectral data were collected in profile mode with full width at half-maximum（FWHM） set at 0.7 Da.The mass errors of all 20 drugs（molecular weight between 135 and 810） were within the range from-22.4×10-6 to 36.1×10-6,among them 90% of the drugs achieved a mass accuracy better than 10×10-6.The new method can provide accurate mass measurements on unit mass resolution mass spectrometers.
