| TI: |
Title
Mass discrimination in the analysis of polydisperse polymers by
MALDI time-of-flight mass spectrometry. I. Sample preparation
and desorption/ionization issues |
| AU: |
Author
Li, L; Schriemer, DC |
| AF: |
Affiliation
University of Alberta; University of Alberta |
| SO: |
Source
Analytical Chemistry (USA), vol. 69, no. 20, pp. 4169-4175, 15
Oct. 1997 |
| NT: |
Notes
54 ref., Spectra, Graphs |
| PB: |
Publisher
USA |
| IS: |
ISSN
0003-2700 |
| AB: |
Abstract
A study of the experimental effects on the matrix-assisted laser
desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometric
analysis of polydisperse polymers is presented, based on a time-lag
focusing TOF configuration. Polydisperse polymers were simulated
with the preparation of multicomponent blends of polystyrene of
narrow polydispersity. Spectral collection was based on one sample
preparation procedure. It is shown that many experimental parameters
give rise to mass discrimination in the signal generated from
a mass spectral analysis of polydisperse polymers. Several issues
related to sample preparation and desorption/ionization are addressed
in this work, and the instrumental considerations such as ion
focusing, transmission, and detection are presented in the following
article in this issue. It is demonstrated that sample preparation
and desoprtion/ionization can introduce serious mass biasing that
appears to be due to the characteristics of the MALDI process.
Experimental procedures are discussed that allow for the determination
of this mass discrimination. Sample preparation guidelines are
suggested for the minimization of mass discrimination. It is stressed
that, with our current understanding of the MALDI process, great
care must be exercised in interpreting average molecular weights
and molecular weight distribution functions deduced from the direct
MALDI analysis of polydisperse polymers. |
| LA: |
Language
English |
| PY: |
Publication Year
1997 |
| PT: |
Publication Type
Journal Article |
| DE: |
Descriptors
Journal Article; Polystyrene resins, Physical properties; Mass
spectroscopy; Lasers; Molecular weight; Molecular weight distribution;
Specimen preparation; Accuracy; Precision |
| CL: |
Classification
B1 Structural Analysis |
| EM: |
Entry Month
9712 |
| SF: |
Subfile Name
Engineered Materials Abstracts, Polymers |
| AN: |
Accession Number
199712-B1-P-0084 |
