STUDY OF X-RAY-FLUORESCENCE SPECTROMETRY AND SPARK ABLATION INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY FOR CHROMIUM DETERMINATION IN FERROCHROMIUM FROM BULK METAL SAMPLES

A study of chromium determination in ferrochromium by X-ray fluorescen ce and spark ablation inductively coupled plasma atomic emission spect rometry was made. Bulk test samples were prepared by re-melting the fe rroalloy diluted with iron in an induction furnace. Calibration sample s were obtained from an industrial ferroalloy, using different FeCr+Fe dilution ratios, in order to cover the chromium concentration range t hat is probably present in these materials. A study is presented of th e influence of the carbon contents on Cr Kalpha line intensities and o n the amount of spark aerosol produced, as well methods of compensatin g for the effect. The total variance and the average instrumental vari ation were calculated from the values obtained for samples with the sa me chromium concentration and variable carbon contents. The criterion applied to test the agreement of the two methods showed that the diffe rence between the results provided by both techniques can be explained by random errors. Accuracies were tested by analysing a series of fer rochromium reference materials.