Matrix-assisted laser desorption/ionization.
Characterization of pyrene end-labeled poly(ethylene glycol) by high resolution MALDI time-of-flight mass spectrometry†
Article first published online: 22 APR 2003
© 1996 Hüthig & Wepf Verlag, Zug
Macromolecular Rapid Communications
Volume 17, Issue 1, pages 59–64, January 1996
How to Cite
Whittal, R. M., Li, L., Lee, S. and Winnik, M. A. (1996), Characterization of pyrene end-labeled poly(ethylene glycol) by high resolution MALDI time-of-flight mass spectrometry. Macromol. Rapid Commun., 17: 59–64. doi: 10.1002/marc.1996.030170109
- Issue published online: 22 APR 2003
- Article first published online: 22 APR 2003
- Manuscript Revised: 9 OCT 1995
- Manuscript Received: 4 AUG 1995
We report the characterization of a sample of poly(ethylene glycol) (PEG, Mn = 3841, Mw/Mn = 1.01), and its derivative end-labeled with pyrenebutyrate groups, using high resolution MALDI time-of-flight mass spectrometry. A matrix of 2-(4-hydroxyphenyl-azo)benzoic acid containing a trace of either sodium chloride or potassium chloride was employed for laser desorption. Peaks due to the sodium or potassium cationized polymers were obtained, equally spaced at 44 mass units apart. For the pyrenebutyrate diester, the analysis shows that 80 ± 2% of the chains were doubly labeled, with the ramaining chains containing only a single pyrene group. Molecular weight determinations for both sets of samples were entirely consistent with size-exclusion chromatography measurements, but were obtained with greater accuracy and less ambiguity about the influence of the end groups on the hydrodynamic radius of the polymer.