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This overall study aims to investigate gradient elution ion-exchange chromatography of pharmaceutically relevant compounds using universal nebulisation detectors, such as evaporative light scattering detection (ELSD). Addition of organic solvents to the eluent is necessary to minimise hydrophobic adsorption on the polymeric stationary phase and improve solubility of analytes. It is also necessary to de-salt the eluent prior to detection, and in this work, ion chromatography suppressors were used for this step. Such suppressors have been designed for aqueous eluents, so the purpose of the present study was to investigate the effects of methanol and acetonitrile on suppressor performance. Chemical and electrolytic suppressors were evaluated for baseline drift, noise and efficiency of suppression using aqueous/organic eluents containing up to 40% (v/v) methanol or acetonitrile. Chemical suppression of aqueous/organic eluents showed minimal noise levels, uniform low baseline and low gradient drift. Electrolytic suppression gave good performance, but with higher baseline conductivity levels and baseline drift than chemical suppression. The elevated baseline was found not to be caused by incomplete suppression of the eluent, but was attributed to chemical reactions involving the organic solvents and facilitated by high electric currents and heat generation. It was demonstrated that suppressed ion-exchange separation using a complex KOH elution profile could be coupled with ELSD, with the suppressor effectively de-salting the eluent, producing a stable baseline. Finally, complementary separation selectivity was demonstrated using a set of pharmaceutically related organic acids separated by reversed-phase and ion-exchange methods.

Item Type:	Refereed Article
Research Division:	Chemical Sciences
Research Group:	Analytical chemistry
Research Field:	Separation science
Objective Division:	Manufacturing
Objective Group:	Human pharmaceutical products
Objective Field:	Human pharmaceutical products not elsewhere classified
UTAS Author:	Karu, N (Dr Naama Karu)
UTAS Author:	Dicinoski, GW (Associate Professor Gregory Dicinoski)
UTAS Author:	Haddad, PR (Professor Paul Haddad)
ID Code:	76357
Year Published:	2011
Web of Science® Times Cited:	18
Deposited By:	Chemistry
Deposited On:	2012-03-05
Last Modified:	2017-10-29
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