IONICON releases a new tool for all PTR-TOF systems for advanced mass-scale calibration.
The built-in PerMaSCal unit uses permeation to add a high mass peaks of stable intensity to every spectrum. These signals represent ideal references for accurate, automated TOF mass-scale calibration and other tuning tasks without affecting typical measurement set-ups.
In a Time-of-Flight (TOF) analyzer, the flight time of an ion is converted into mass information. This quadratic relation needs to be precisely determined for the PTR-TOFMS instrument’s capability to resolve the atomic composition of protonated VOCs by exact mass measurement. Temperature variations of the TOF-MS can cause a slow change in the length of the ion’s flight path over time. Therefore, frequent calibration of the mass scale using known peaks over an extended mass range is recommended for a high mass accuracy.
The key to this simple process is to find the appropriate peaks for mass scale calibration: Peaks have to be present in all mass spectra at suitable intensity levels, i.e. high enough to provide a sufficient signal-to-noise ratio but well below detector saturation. Moreover, they should not overlap with other compounds.