Sequence distribution of beta-hydroxyalkanoate units in bacterial copolyesters determined by desorption chemical ionization mass spectrometry.

The sequence distributions of poly(beta-hydroxyalkanoate) copolymers were determined by analyzing oligomers obtained by the pyrolysis direct-chemical-ionization (DCI) mass spectrometry technique. Oligomers up to nonamers were identified and the comparison between the experimental and calculated peak intensities makes it possible to calculate repeating unit compositions and sequence distributions. Comparisons with other earlier methods are given.