Optimization of Operational Conditions for Scandium Determination in Aluminum Alloys by Inductively Coupled Plasma Optical Emission Spectrometry

A method for the determination of scandium (Sc) in aluminum alloy samples by inductively coupled plasma optical emission spectrometry was developed. The method was optimized by the Box-Behnken design, which evaluated the operational conditions (radio frequency power, nebulizer gas flow rate, and sample flow rate). The optimum conditions were established as a radio frequency power of 1300 W, a nebulizer gas flow rate of 0.83 L/min, and a sample flow rate of 0.9 mL/min. Satisfactory performance characteristics (background equivalent concentration, limits of detection and quantification) were obtained under the optimum conditions. The method proposed using the optimum conditions allowed Sc determination with limits of detection and quantification of 0.15 and 0.48 mu g/L, respectively. The accuracy of the proposed method was confirmed by analyzing an aluminum alloy certified reference material and performing a standard addition method. The standard addition experiments resulted in recoveries between 96.5% and 105%. The method developed has been applied to the Sc determination in aluminum alloy samples from the Beijing Institute of Aeronautical Materials, and the recovery study results ranged between 98.0 and 100.5%.