Fig. 4From: Amino acids chemical stability submitted to solid state irradiation: the case study of leucine, isoleucine and valineMass spectra of isoleucine irradiated in absence of air in positive ion mode, at low mass range (a) and at normal mass range (b). The concentration for the samples was 6.7 mM in a solution 1:1 MeOH-AcNH4 45 mM. The mass spectra for l-Ile standard are reported in the Additional file 1 Back to article page