Evaluation of select variables in the ion chromatographic determination of F-, Cl-, Br-, NO3-, SO4-2, and PO4-3 in serum samples

Abstract

A full experimental design at two levels is applied for the estimation of the significance of select factors that may influence the ion chromatography (IC) determination of F-, Cl-, Br-, NO3-, SO4-2, and PO4-3 in serum samples. The factors studied are various sample deproteinization procedures, eluent composition, and flow rates. Deproteinization using either acetonitrile-NaOH or ultrafiltration can be used in order to obtain a significant protein removal before IC analysis; however, the former is recommended because it is less time-consuming and cheaper. Better resolution is obtained when a sodium hydroxide solution is used as the eluent. There is no influence of the sample's deproteinization procedures on the chromatographic resolution.