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Application of parylene for surface (polymer) enhanced laser desorption/ionization of synthetic polymers
Author(s) -
Miksa Beata J.,
Sochacki Marek,
SrokaBartnicka Anna,
Uznański Paweł,
Nosal Andrzej,
Potrzebowski Marek J.
Publication year - 2013
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.6516
Subject(s) - polymer , chemistry , desorption , ethylene glycol , monomer , parylene , molecular mass , mass spectrometry , polymer chemistry , chemical engineering , matrix assisted laser desorption/ionization , analytical chemistry (journal) , adsorption , chromatography , organic chemistry , engineering , enzyme
RATIONALE Synthetic polymers of molecular masses up to a few kDa can be analyzed without the use of any matrix by direct laser desorption/ionization mass spectrometry (LDI‐MS). In this technique, the surface of the sample plate plays a crucial role, and many attempts have been made to understand the influence of the surface on the ease of desorption. Since this technique requires no tedious sample pretreatment, it is a promising method for the rapid characterization of various synthetic polymers. METHODS Parylene (poly( p ‐xylylenes), PPX) was tested as a surface support for studying the molecular masses of biocompatible polymers: poly(ethylene glycol) (PEG), poly(L‐lactide) (PLLA), and poly(methyl methacrylate) (PMMA). The average molecular masses of the polymers were: PEG (600.0 Da and 3.5 kDa), PMMA (2.0 kDa), and PLLA (2.8 kDa). RESULTS LDI mass spectra of polymers deposited on parylene were enhanced by a factor of two over those obtained directly from the gold target plate. CONCLUSIONS Modification of the surface of the target plate by the addition of a PPX layer extended the functionality of LDI‐TOF MS, especially for the analysis of low‐mass compounds. The LDI analysis using the PPX‐coated target plate provided details of polymers including: end‐group, composition, monomer unit, and molecular mass distribution. The average molecular weights of four tested polymers on the gold target plate and the PPX support were unchanged, indicating that sample degradation was not occurring despite the high energy of the laser beam. The LDI investigations showed that the PPX support boosted ion yields by a factor of two compared with the gold target plate. Copyright © 2013 John Wiley & Sons, Ltd.