Automated Exact Mass Measurements and Elemental Composition Determinations
The JEOL AccuTOF™ LC/MS system offers easy exact-mass measurements and elemental composition determinations. A robust design and stable time-of-flight mass analyzer are combined with a detection system that provides high sensitivity and high dynamic range. Unlike other API/TOF mass spectrometer systems, the AccuTOF™ provides excellent linearity and mass accuracy over a wide range of analyte concentrations.
To demonstrate the potential of the AccuTOF™ for automated exact mass measurements, a variety of small-molecule drug samples were measured by using a macro that allows the user to submit samples for unattended elemental composition determinations. Samples were introduced by using the LC autosampler. The macro applied an automatic drift (“lock mass”) correction to the reserpine reference standard and printed out elemental compositions for user-specified elemental limits. The results show high accuracy and stability regardless of sample concentration.
Mass Accuracy vs. Sample Concentration
Figure 1. shows the mass accuracy for measurements of flow injections of methanol solutions of chlorpromazine (C17H20N2ClS) with concentrations ranging from 9 ppb to 900 ppm. Quinine (400 ppb) was added to the samples as a drift correction. All mass measurements are within 5 parts per million (ppm).