Accurate Mass Determination Using Time-of-Flight Mass Spectrometer

This application note presents a study on the accurate mass determination of narrow electrophoretic peaks using an orthogonal acceleration time-of-flight (oa-ToF) mass spectrometer. The investigation focuses on the coupling of the Micromass LCT to capillary zone electrophoresis (CZE) for the analysis of a drug substance and its related impurities. The document outlines the methodology employed, including the use of a PrinCE Model 450 CE System and specific buffer compositions. It details the mass spectrometry process, including the formation of positively charged ions and the operational parameters of the mass spectrometer. The results demonstrate the effectiveness of the CZE-oa-ToF system in achieving high-resolution mass measurements with accuracies below 7 ppm. Additionally, the note discusses the reproducibility of migration times and the potential for quantification using the oa-ToF mass spectrometer, highlighting the linear calibration curves obtained during the study. Overall, the findings indicate the successful integration of CZE with oa-ToF mass spectrometry for precise mass analysis.