A Direct Deposition Method for Coupling Matrix-assisted Laser Desorption/Ionization Mass Spectrometry with Gel Permeation Chromatography for Polymer Characterization

✍ Scribed by Camille E. Kassis; Joseph M. DeSimone; Richard W. Linton; Edward E. Remsen; Gary W. Lange; Robert M. Friedman

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 164 KB
• Volume: 11
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(19970630)11:10<1134::aid-rcm910>3.0.co;2-0

✦ Synopsis

Matrix-assisted laser desorption/ionization (MALDI) measurements of polymeric materials of narrow polydispersity provide molecular weight measurements that agree closely with those from conventional tools such as gel-permeation chromatography (GPC). However, materials that have a broader molecular weight distribution (polydispersity) > 1.1) have been shown to diminish the accuracy of the MALDI results. In a recent effort to overcome this limitation, some researchers have utilized GPC prior to MALDI analysis to collect fractions with narrower molecular weight distributions. In our research, the GPC eluent was spray deposited onto a rotating matrix-coated substrate and the resulting polymer 'trail' was characterized directly by MALDI. Specifically, molecular weight information was determined using various points along poly(methyl methacrylate) sample 'trails' deposited on a matrix of trans-3-indoleacrylic acid. The overall number-average molecular weight (M n ) and molecular weight distribution (MWD) for each of the samples were calculated. The M n values are in fairly good agreement with manufacturer's values, though the MWD values determined by MALDI are narrower.