Possibilities and limitations of quadrupole mass spectrometric detector in fast gas chromatography

In this work the application and limitations of a common bench top quadrupole mass spectrometer was evaluated for the qualitative and quantitative measurement of n-alkanes and pesticides of a wide range of volatilities and polarities with fast GC separations using 0.15 mm I.D. narrow-bore capillary columns. It was found that the spectra acquisition rate has a great impact on sensitivity (peak areas, peak shapes and S/N ratios). The quality of the obtained spectra is not significantly influenced in the full scan monitoring mode for the fastest scan rates. For quantitative analysis a selected ion monitoring mode is able to acquire the sufficient number of data-points for the proper peak shape reconstruction and good repeatability of peak areas measurements expressed by RSD (<5%) for all tested dwell times shorter than 75 ms. However, for shorter dwell times, S/N ratio is lower, while peak areas are not influenced.