Author Description

The method of analysis is applicable to samples with tin and zinc contents from 15 ug/g upwards. Samples with widely ranging concentrations of the analytes are diluted with river sand. The matrix variation are compensated for by the use of briquettes containing coarse river sand, a styrene copolymer binder, and an internal standard. Tungsten is used as the internal standard for zinc, and antimony for tin. Calibration graphs for zinc and tin are obtained by the use of a reference material for tin and of zinc oxide for zinc. The precision of the analysis for each element does not exceed 0,040 relative standard deviation. The agreement between the analysis and the accepted international values and recommended values for in-house reference materials is better than 3 per cent over the concentration range 50 ug/g to 16 per cent. The lower limits of detection are 2 ug/g for tin and 3 ug/g for zinc. The overall time required for the analysis of 10 samples, one control sample, and five calibration standards is approximately 3 hours.