Effect of column overloading and its influence on the quality of analytical results in the determination of inorganic ions by ion chromatography

The effect of concentration of the sample ion macroconstituent on precision and accuracy of chromatographic analysis has been studied. The limiting conditions enabling correct analysis of several inorganic ions in aqueous solutions using anion and cation exchange analytical columns of type Dionex ion Pac AS4A, AS5, AS9SC, Fast Anion-1, and CS10 were established. The basic parameters of chromatographic process such as: retention time, peak area, column efficiency and peak shape parameters were calculated as a function of ion macroconstituent concentration in the analyzed solution for each investigated column and for three anions (Cl-, NO3-, SO42-) as well as four cations (NH4+, Na+, Mg2+ and Ca2+), each of which served in turn as a macroconstituent. After establishing limiting concentrations of the particular ions below which a column overloading effect does not occur, the detection limits, precision and accuracy of determinations of investigated inorganic ions in water samples were evaluated.