Fig. 21 The spectra of DHB, DAN and norharmane matrix
Considering quite similar performance of different matrices in positive ionization mode, in our opinion DHB matrix could be chosen as the first selection (see Fig. 21). Norharmane matrix could be rejected since it changes the ion map – probably as a result of the solvent properties. As it was noted, for several m/z values, we obtained different ion maps in comparison with DHB matrix. Generally, DHB matrix gives higher peaks intensity and s/n ratio. Thus, for the measurement of lipids in the positive ion mode, we recommended this matrix.