Determination of chromium,aluminum,iron,magnesium and silicon in chromium ore by alkali fusion-inductively coupled plasma atomic emission spectrometry

Chromium ore samples were fused by alkali and then leached out by hydrochloric acid.After the analytical lines of the elements were selected,the conditions of sample uptake,carrier gas flow,cooling gas flow and RF power were optimized with the system of SeaSpray nebulizer and cyclone spray chamber,based on the principle of best signal stability.The determination of chromium,aluminum,iron,magnesium and silicon in chromium ores was fulfilled.The matrix effect was discussed: When the concentrations of sodium was 3.1-4.0 mg/mL and zirconium was 20 μg/mL,they did not interfere with the determination of testing elements;When the concentration of sodium was 3.5 mg/mL,the interference among the coexisting elements could be ignored.The acidity effect was also investigated.When the volume fraction of acid was about 7 %-11 %,the effect of acidity on each testing element could be ignored.This method has been applied to the determination of four certified reference materials.The found values were in good agreement with the certified values.The relative standard deviation(RSD) was 0.2 %-0.9 %(n=5).