A STUDY OF CATION ATTACHMENT TO POLYSTYRENE BY MEANS OF MATRIX-ASSISTED LASER DESORPTION IONIZATION AND ELECTROSPRAY IONIZATION-MASS SPECTROMETRY/

A range of metal cations has been shown, by means of matrix assisted l aser desorption/ionization (MALDI) and electrospray ionization (ESI) m ass spectrometry, to form adduct complexes with polystyrene, Both MALD I and ESI mass spectra contain adduct ion peaks corresponding to [PS Cat](+), where PS represents a polystyrene molecule and Cat a cationi c species. In addition, salt cluster complexes assigned as [PS + M(MX) (n)](+), where MX represents the metal salt, M the metal cation and n = 1 or 2 are observed in ESI spectra, The most favourable interaction between cation and polymer, for MALDI experiments involving dithranol as the matrix, occurs when either silver or copper ions are the dopant cations, whereas the addition of potassium salts leads to the most in tense and reproducible ESI spectra, It has been established that there are several problems associated with the analysis of synthetic polyme rs in an ESI-quadrupole instrument which are not found in the correspo nding MALDI-TOF experiments. (C) 1997 by John Wiley & Sons, Ltd.