A further method for chloride analysis of cement and cementitious materials — ICP-OES

This paper describes the novel application of inductively coupled plasma-optical emission spectroscopy (ICP-OES) for the analysis of the chloride content in various South African cements and cementitious materials. Samples were introduced into the plasma as slurries, with and without 5% (v/v) nitric acid. They were agitated in an ultrasonic bath for 10 min to fully disperse and stabilize the slurries. Calibration was performed by using aqueous solutions of reference materials. Measurements were made on a simultaneous SpectroCIROSCCD ICP-OES with side on plasma. The accuracy of the chloride determination was verified by the analysis of certified reference material. The findings of this investigation are compared with results obtained for the chloride content by the standard EN196-2 indirect Volhard titration and potentiometry with an ion-selective electrode (ISE), previously described as the preferred method. The results obtained with potentiometry and ICP-OES of various commercially available cements were comparable.