Three ionisation modes (EI-MS+ electronic impact, chemical ionisation with positive CI-MS ion detection and negative
CI-MS ion detection) were used. The information obtained with these three modes differed somewhat. The negative
CI-MS technique limits the number of peaks obtained on molecular and plastic mass spectra. It was easier to interpret
these spectra than spectra obtained with positive EI-MS and positive CI-MS. Fig. 1 shows the mass spectra obtained using
different ionisation methods for MACB.