In this paper, results will be presented showing the possibilities for further improvement of a semi-quantitative standardless model applied routinely in fast-flow glow discharge mass spectrometry (GD-MS). This approach widely used in GD-MS analytics and is based on standard relative sensitivity factors (StdRSF). These were determined for the fast-flow GD-MS instruments using iron matrix standard reference materials and DC continuous plasma excitation. In the presented work, measurements were carried out to extend the StdRSF to further matrices as well as to µs-pulsed DC excitation. The optimization of the StdRSF was done for a large number of elements in Al, Cu and Fe matrices using three different instruments and by applying DC continuous as well as DC pulsed glow discharge excitation. The effects of the gas flow and gas pressure on the StdRSFs were also studied.