Discrimination and quantitation of halobenzoic acid positional isomers upon Th(IV) coordination by mass spectrometry.

A fast and reliable mass spectrometry-based method has been developed to discriminate the positional isomers of -, - and -CHXCOH (X = F, Cl and Br). This is based on the distinct fragmentation patterns of isomeric ThCl(CHXCO) ions generated by electrospray ionization of the solutions with CHXCOH isomers and ThCl. Moreover, the composition of these positional isomers can be conveniently quantified without any pre-treatment according to the proportion of gas-phase fragmentation products.