Abstract:The contents of magnesium (Mg), aluminum (Al) and copper (Cu) in an IR interfering smoke material directly affect the anti-interference performance. Chemical titration is a traditional method for determining the content of metal element, it is complicated and time consuming, and each element can only be determined sequentially. Besides, the quantification of Mg cannot be performed in the presence of both Al and Cu. An inductively coupledplasma optical emission spectroscopy (ICP-OES) coupled with a sample pretreatment method was developed in this work to quantitatively determine Mg, Al and Cu. Specifically, the sample was digested with concentrated nitric acid, and the ICP-OES analysis was directly performed on the digested solution after filtration and dilution. When the resonance lines 279.5 nm, 167.0 nm and 324.7 nm were selected for determination of Mg, Al and Cu, the limits of detection (LODs) of them were 0.013 μg/mL, 0.040 μg/mL and 0.025 μg/mL, respectively. The spiked recoveries for the three elements were in the range 102-105%, and the relative standard deviations (RSDs) were in the range 1.0% ~ 3.0% (n = 8), indicating that both the accuracy and the precision of the method are good. This work traced the total standard deviation of the developed method and compared it with the results of complexometric titration. It showed that there was no significance difference between the results of the two methods. However, the developed ICP-OES method was simpler and faster, and able to determine the three elements simultaneously. It can be completely substituted for traditional chemical titration method.