Study On Analysis Of Target Elements And Its Application In Nonmetallic Materials

The application of elemental analysis method in non-metallic materials such as mineral products and polymers is an important research direction of element analysis.It is of great significance to identify and control the quality of import and export products by using the accurate and reliable analysis of the target elements in the material quickly,accurately and effectively.In this paper,the elemental analysis method in the mineral products was studied,and the analysis method of rare earth elements in copper concentrate was established by using the Inducted Coupled Plasma Mass Spectrometry（ICP-MS）and effective mixed acid dissolving system.Based on the production process of polymer reference materials（RM）,the products of plastic,leather,textile,paint coating are studied by the application of ICP-MS,Inductance Coupled Plasma Optical Emission Spectrometer（ICP-OES）,Energy Dispersion X-Ray Fluorescence spectrometer（EDXRF）,which is used to analyze the target elements,and developed the polymer RM that is used for the quality control of the product.The results of the research are as follows:（1）Based on the characteristics of copper concentrate composition and the action mechanism of different acids,the mixed acid digestion system of nearly 200 copper concentrate samples from different mining areas in 8 countries was studied.It was found that the rational mixing ratio and adding order of acid had a positive effect on the digestion of copper concentrate.The optimum digestion system of 3 m L Hydrofluoric acid（H）-1 m L Perchloric acid（P）-3 m L Lefort aqua regia（L）was obtained.The signal response and interference of target elements such as rare earth elements in copper concentrate before and after opening the High Matrix sample Injection system（HMIs）were compared by ICP-MS.It was found that when HMIs was turned on,the tolerance stability of plasma was greatly improved and the matrix effect was reduced.Experiment obtained 15 rare earth elements,such as the correlation coefficient were above 0.9993,the recoveries were 98.3%～107.7%,the precision was less than 2.9%,and the detection limits were 0.00404μg·L^-1～0.03623μg·L^-1.（2）According to the synthesis principle and process flow of different polymer materials,plastic RM,leather RM,textile RM and paint coating RM containing target elements such as Lead（Pb）,Chromium（Cr）,Cadmium（Cd）,Mercury（Hg）and Bromine（Br）were developed.The homogeneity and stability were evaluated by F-test,T-test and other statistical methods.It was found that according to the production and processing process of polymer,the polymer RM with uniform and stable content of target element could be obtained by adding the target element compound and matching additives together.One case study was performed with ISO Guide 35 and GB/T 15000.3,a series of polymer RM with good homogeneity and stability,can effectively supplement and support the written standards at the technical level.Based on the research and testing technology of RM,we have completed the formulation of 1 national physical standard and 2 industry standards.（3）Using polypropylene（PP）RM,through the study of the number of sampling points,measurement times of each sampling point,pulse energy and delay time,a quantitative analysis method of Laser Induced Breakdown Spectroscopy（LIBS）technology applied to the content of target elements（Pb,Cr）in plastic was established.It is found that the detector of LIBS can effectively collect the characteristic signals of the target elements in the plasma generated by PP after laser excitation.The linear correlation coefficients of Pb and Cr were0.9992 and 0.9989,and the detection limits of Pb and Cr quantitative analysis methods were35 mg·kg^-1and 28 mg·kg^-1,respectively.This research method made the quantitative analysis of target elements based on LIBS technology possible.（4）Using EDXRF,the method of element analysis in leather RM was studied.It is found that the application of leather RM could achieve the function of matrix matching,and a rapid,accurate quantitative analysis method was established,and an industry standard SN/T5231-2019 was drafted.The experiments have obtained a good verification effect on the data of 10 setting mechanisms.The analysis method of 15 rare earth elements in functional textiles was studied by ICP-MS.It is found that the established analytical method was feasible,and the industry standard SN/T 5288-2022 was drafted.The experimental results show that the precision of the method is less than 3.63%,the repeatability S_ris less than 0.00386,the reproducibility S_Ris less than 0.00463,and the accuracy is within±0.007 mg·kg^-1.（5）Using paint coating RM and self-made extraction device,the separation method of coating and soft glue solvent was established.It was found that dichloromethane,ethyl acetate is the best solvent for the separation of soft rubber and its surface coating.Based on the Analysis of target element lead,an effective separation effect was obtained in the experiment.The high temperature yellowing resistance of glycerol was studied based on different additives and amounts.It was found that when the minimum dosage of additive is 1.0%,glycerol had the ability of high temperature yellowing resistance while maintaining its own performance.The preparation method of high temperature yellowing resistant glycerol was obtained.