Analysis of Amber Components by Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight Mass Spectrometry

A widely used and powerful "soft" ionization method, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), was used for the qualitative analysis of amber from different production areas (Baltic sea region, Myanmar, Dominican Republic, Mexico and Fushun, China) in positive ion mode. When a carbon film as the matrix, the mass spectra of all samples are evident to show that, the molecular weights of analytes which could be ionized into a quasimolecular ion are similar and distribute in the ratio of mass per charge (m/z) in 60-250, 250-800, and 900-1 900. They are relevant to low-mass, medium-mass and high-mass chemical compositions in amber. The low-mass components are easier ionized than the highly-polymerization medium-mass and high-mass ones. The varieties of ionizable components lower in amber with greater maturity, indicated the non-volatile components' contents increasing. On the other side, with the increase of oxidation, the varieties and abundance of low-mass components decrease, while that of medium-mass components trends to increase.