Abstract
A method for the simultaneous determination of Mg and Ca ions in solar salt was studied by ion chromatography with a conductivity detector. The samples, about 25g, were dissolved in about 150ml of water and the solution was filtered through a filter paper into a 250ml volumetric flask. Then 1ml aliquot of this solution was pipetted into a volumetric flask and diluted to 100ml with water. A 100μl aliquot of the sample solution was analyzed by an ion chromatograph equipped with a precolumn (PCX 1,50mm×4.6mm i.d.) and a separation column (SCX 1,250mm×4.6mm i.d.) using 2 mM ethylenediamine-4 mM tartaric acid as a mobile phase (2ml/min).
Linear calibration curves were obtained up to 2.0 ppm for Mg and Ca. The detection limits (S/N=3) were 5 ppb for Mg and 7 ppb for Ca. Relative standard deviations (n=5) were less than 3.1% for 0.016-0.09% of Mg and 2.8% for 0.0420.20% of Ca in solar salt for the simultaneous determination of these elements.
