The analysis of geological materials for fluorine,chlorine and sulphur using pyrohydrolysis and ion chromatography

A rapid, efficient and interference-free method of determining fluorine, chlorine and sulphur in geological materials is described. The proposed pyrohydrolysis-ion chromatographic method was optimised by investigating experimental conditions and the results were compared with established methods using in-house control samples. Accuracy was evaluated by analysis of 13 international reference samples and found to be excellent for all three elements. The limit of determination for a 100-mg sample is 20 μg g^?1 for the three elements and the precision averages about ±5% relative standard deviation at levels greater than 100 μg g^?1 up to percent amounts. Sample preparation is minimal, possibility of contamination negligible and cost per analysis low. The productivity rate is about 40 samples per day with one operator using two furnaces and the automated chromatograph.