Selectivity of electrospray response in small polymer analysis by mass spectrometry.
The selectivity of electrospray was explored for a small poly(ethylene)glycol by comparing the oligomer response obtained from direct polymer introduction in flow injection analysis with the signal recorded in high-performance liquid chromatography/mass spectrometry (HPLC/MS). When the oligomer mixture was ionized, a suppression effect was measured for all but the more hydrophobic congeners for which the response was enhanced. This result would reflect the influence of electrospray droplet chemical composition on the equilibrium partitioning coefficient in Enke's model. On average, the electrospray selectivity observed for the studied poly(ethylene)glycol did not affect the molecular weight distribution parameters as response for the most concentrated oligomers was suppressed to the same extent while over-expressed largest congeners had a low contribution to the total polymer sample.
Mohamed
Salimo
S
Aix-Marseille University, Department of Chemistry, JE 2421, F-13397 Marseille, France.
Charles
Laurence
L