Simultaneous optimization of reagent concentration and pH in reversed-phase ion-pairing chromatography

• Published in: Journal of Chromatography A 1987-01, Vol.384, p.153-162
• Main Authors: Billiet, Hugo A., Vuik, Johan, Strasters, Joost K., De Galan, Leo
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; Other chromatographic methods
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(01)94667-9

The procedure developed earlier by the authors for simultaneous two-parameter optimization in reversed-phase liquid chromatography has been adapted to ion-pair chromatography. From the many parameters controling reversed-phase ion-pair chromatography, the mobile phase concentration of the ion-pair reagent and the pH exert the largest effect on selectivity. Initial chromatograms are chosen to cover the parameter space such that a good initial estimate of the optimum can be obtained. The true retention behaviour is approximated iteratively, and the optimum is located in a few additional chromatograms. The procedure can be followed through appropriate visualization of the results obtained in each stepin the iterative procedure. Two samples were subjected to the procedure, one containing only anions, the other containing cations, anions, and neutral molecules. The ion-pair reagents were sodium octylsulfonate and tetrabutylammonium bromide. A citrate buffer was used to control the pH between 2.5 and 6.