Quantitative Determination of Barium, Magnesium, Aluminium and Europium in Blue Phosphors for Fluorescent Lamp Using ICP-AES after Alkali Fusion

Abstract

A method for the quantitative determination of barium (Ba), magnesium (Mg), aluminium (Al), and europium (Eu) in the blue phosphor for fluorescent lamps was investigated by means of an alkaline fusion method, followed by inductively coupled plasma atomic emission spectrometry (ICP-AES). About 200 mg of samples were weighed in the Pt crucibles, 3.0 g of sodium carbonate (Na₂CO₃) and 1.0 g of sodium tetraborate (Na₂B₄O₇•10H₂O) added, followed by the fusion. After cooling, 10-20 ml of water and 20 ml of hydrochloric acid (1 : 1) was added. The contents heated on the hot plate were dissolved. After cooling, the solutions were adjusted with water to 250 ml. Ten milliliters aliquot of solutions were diluted with water to 100 ml, sample solutions measured by ICP-AES. Working standard solutions were prepared by addition the amount of Na₂CO₃, Na₂B₄O₇•10H₂O and hydrochloric acid (1 : 1) as same as sample. The four calibration curves obtained from the emission intensities were linear with high correlation coefficient of more than 0.999, respectively, and a good relative standard deviations (RSD, %) of 0.69(Ba15 μg ml^-1), 0.66(Mg5.0 μg ml^-1), 0.84(Al30 μg ml^-1), and 0.47(Eu1.0 μg ml^-1). This method was successfully applied to the determination of four elements in the experimental samples.