Determination of calcium in aluminum metal by flame photometry

A method for the flame photometric determination of calcium in aluminum has been established. Sample of metallic aluminum was taken in a quartz boat covered by graphite powder and placed in a Pyrex combustion tube. The temperature was raised gradually to 200°C in stream of hydrogen chloride to sublime off the matrix aluminum as chloride. Calcium with graphite remained in the boat. The residue was taken up with hydrochloric acid and filtered. The filtrate was concentrated to 2 ml by evaporation and was transferred into a 10 ml volumetric flask. One milliliter of lanthanum chloride solution (20 mg/ml) and 4 ml of ethanol were added, and the mixture was diluted to the mark with water. The solution was atomized into oxyhydrogen flame, and the intensity of 422.7 mμ was measured for determining calcium.