EIMS Fragmentation and MRM quantification of autoxidation products of α- and β-amyrins in natural samples.

EIMS fragmentations of 3β-hydroxy-urs-12-en-11-one and 3β-hydroxy-olean-12-en-11-one TMS derivatives exhibit specific fragment ions, which appear to be very useful for the quantification of these oxidation products in natural samples (riverine particulate matter, wet and dry deposited atmospheric particles).