Measurement of a Dendritic MS Reference Standard
A high-quality mass calibration is required to achieve highly accurate mass measurements by mass spectrometry. A polymer or a mixture of peptides is commonly used to calibrate a MALDI-TOF MS system. However, peptides do not necessarily have long-term stability, and a monodisperse polymer does not have a wide m/z range. Sometimes these standards are not well suited for calibration over a wide m/z range.
We used a new dendritic MS calibrant (SpheriCal®) to resolve these issues. Here we demonstrate measurement and calibration using the new calibrant with the JEOL SpiralTOF MALDI mass spectrometer.
The new SpheriCal® High Range dendritic MS reference standard was obtained from the Polymer Factory (http://www.polymerfactory.com/). The sample was dissolved in tetrahydrofuran at a concentration of 10 mg/mL. A 0.5 μL sample was deposited and dried on the MALDI target plate. An additional matrix was not required because it is already included in the SpheriCal® reference standard mixture.