“…77 Field desorption (FD) was used to characterize porphyrins from mixtures of natural sources as early as 1975; 78 a similar procedure was applied for the characterization of metallophthalocyanins. 79 FD and other ionization techniques were also used to analyse the oxidation products of corroles. 80 Desorption ionization techniques using a liquid matrix, such as fast atom bombardment (FAB) and liquid secondary ion mass spectrometry (LSIMS), were also used, for instance to characterize metallated phthalocyanines, 81 and porphyrins, 82,83 and also free base chlorins and bacterichlorins.…”