Determination of barium content in pyrotechnics used for fireworks and firecrackers based on Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF)

Methods used for the determination of barium content in pyrotechnics are mostly based on traditional chemical method, which is lengthy and cumbersome. If inductively coupled plasma emission spectrometry or atomic absorption spectrometry are used to determine the barium with high content, the sample solution must be highly diluted, and it must produce errors in measurement and call into question the reliability of the data. The method mentioned in this paper is about the determination of barium content in pyrotechnics used for fireworks and firecrackers based on energy dispersive X-ray fluorescence spectrometry by controlling matrix effects between elements. Using sample solution of pyrotechnics in specific concentrates, the barium content can be determined by the specific calibration curve established with an intensity calibration. This method can provide high accuracy and good precision in a short time with a simple process by efficiently controlling the matrix effects. It can fully meet the requirements for the determination of barium in pyrotechnics used for different kinds of fireworks and firecrackers around the world, and it has good generalization and practicability. The average recovery of the method can be 98.95%~100.79%, allowing for a difference of 0.5%. Introduction In China, fireworks and firecrackers are very important consumer recreational products in people’s everyday life since ancient times. Gorgeous colors produced by fireworks and firecrackers are even the barium ing role of foiling festal atmosphere in every grand holiday celebrations. In recent years, with the rapid development of global trade, fireworks and firecrackers are becoming more and more popular all over the world, more and more consumers are fascinatedby different kinds of patterns, pictures, and sound effects of fireworks and firecrackers. Barium element is commonly found in barium nitrate and barium carbonate as primary content used for pyrotechnics. Quantitative analysis of chemical compositions in pyrotechnics such as barium content is required under the Globally Harmonized System of Classification and Labeling of Chemicals(GHS)to be complemented in the fireworks and firecrackers industry. Meanwhile it will also provide a scientific and effective technical support to the management and supervision of safety production for the government, and improve products’ quality level by the manufacturers. It can also be utilized as a tool in providing valuable data in the judgment in some major arbitration and security incident analysis. Quantitative analysis method of the barium content reported in current literature is limited to traditional chemical analysis, such methods have the following disadvantages:(1) Long detecting period. Generally, it will take a skilled technician two whole days or so to complete the detection.(2) The operation is more complicated. It needs to go through many steps such as dissolving sample, filtration, precipitation collection, drying and weighing precipitation and ect. Comparing with traditional chemical analysis methods ,this method based on energy dispersive X-ray fluorescence spectrometry(EDXRF) has the 2017 International Conference on Materials, Energy, Civil Engineering and Computer (MATECC 2017) Copyright © (2017) Francis Academic Press , UK 1 advantages of simple operation steps, short period of detection, high accuracy and good precision. Theory Barium element is commonly found as primary content in chemical materials such as barium nitrate and barium carbonate in pyrotechnics used for fireworks and firecrackers. Statistical analysis shows that barium nitrate and barium carbonate in pyrotechnics is between 20% to 50% ,it can concludes that the barium content in pyrotechnics would be 10%~35% as mass fraction.Concept of the method: considering the weight of the sample is 2.0 g,constant volume is 1 L and the concentrations of the barium would be controlled in 0.2 g/L~0.70 g/L in sample solutions. And it can prove that when the barium content in the solution is in the range of 0.15 g/L~0.73g/L, there would be little matrix effects among elements. So we can establish a working curve which contains the barium elements with the content of 0.15 g/L~0.73 g/L to determine the barium content in the sample solution. In accordance with the relevant safety regulations, the sample was ground into powder of less than 180 micron. Then the sample powder is placed in an explosive‒proof oven at 50°C ‒55°C and dried for 4 hours, and then placed into a dryer for cooling down to room temperature. Pretreated sample is fully dissolved in 150mL nitric acid and then filtered into volumetric flask as sample solution. The sample solution can be put into the sample cup and placed in the tank of the EDXRF to measure the fluorescence intensity of the barium elements. The actual content of barium element in the sample can be calculated from the concentrations of the barium reading by the working curve. Experiment section Reagents Unless otherwise stated, all the reagents should be guaranteed reagents and pure water is secondary grade water as described in ISO 3696(1987). Nitric acid (1+1): mix nitric acid and pure water thoroughly according to the proportion of 1:1. Standard working solution of the barium nitrate: Weigh 3.0 g high purity barium nitrate powder reference materials (accuracy to 0.1 mg), and put it in a 300 ml beaker, add 150 mL pure water, heat the beaker and make the sample solution slightly boiling on an electric stove for 10 min. After the solution is cool down to the room temperature, transfer the solution into a 500 ml volumetric flask, add 10 mL nitric acid (1+1) and pure water to the scale.Then we can separately pipette the standard working solution of the nitric acid with volume 5 mL、10 mL、15 mL、20 mL、25 mL、30 mL、35 mL and 40 mL into eight 100 mL volumetric flasks which marked from N1 to N8, and add pure water to reach 100 mL in each volumetric flask, mix thoroughly for later use. Concentrations of the standard working solution in different flasks are shown in Table 1.