Mass distribution measurement of water-insoluble polymers by charge-reduced electrospray mobility analysis

Ku, BK; Fernandez de la Mora, J; Saucy, DA; Alexander, JN

HERO ID

3539864

Reference Type

Journal Article

Year

2004

Language

English

PMID

14750880

HERO ID 3539864
In Press No
Year 2004
Title Mass distribution measurement of water-insoluble polymers by charge-reduced electrospray mobility analysis
Authors Ku, BK; Fernandez de la Mora, J; Saucy, DA; Alexander, JN
Journal Analytical Chemistry
Volume 76
Issue 3
Page Numbers 814-822
Abstract 1-Methyl-2-pyrrolidone (NMP) seeded with 5% trifluoroacetic acid is identified as a singular buffer, polar enough to produce fine electrospray drops, yet having excellent solubility for many industrial polymers such as polystyrene (PSR) and poly(methyl methacrylate) (PMMA). Four PSR mass standards (M = 9.2, 34.5, 68, and 170 kDa) with narrow mass distributions are electrosprayed from their solutions in this buffer. The high charge on the resulting ions is reduced to unity with a radioactive source, whereby their electrical mobility distributions, determined by a differential mobility analyzer, yield unambiguously their size distribution. Each standard produces (at high solution concentration) several mobility peaks associated with the formation of particles containing from one to six polymer molecules, used to establish a relation Z(M) between electrical mobility Z and polymer mass. Within the indeterminacy given by inaccuracies in the nominal masses of the standards, this relation indicates that the polymers form spherical balls with a density close to the bulk density of polystyrene, as seen previously with poly(ethylene glycol) chains. Good mobility spectra from the same buffer are also obtained for PMMA (M = 49 kDa). Because NMP is less conductive and contains more involatile impurities than common aqueous buffers, the electrospray ions formed tend to carry a small contaminant crust, which distorts the inferred mass distribution unless a high spray quality is achieved.
Doi 10.1021/ac034594a
Pmid 14750880
Wosid WOS:000188823900047
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English