A novel strategy of anti-interference for solid dilution in elemental analysis using spontaneous surface dispersion theory

Authors: WANG, BO - Chinese Academy Of Agricultural Sciences; LIU, TENGPENG - Chinese Academy Of Agricultural Sciences; LIU, JIXIN - Chinese Academy Of Agricultural Sciences; MAO, XUEFEI - Chinese Academy Of Agricultural Sciences; NA, XING - Beijing Academy Of Agricultural Sciences; Chen, Guoying; LIU, MEITONG - Chinese Academy Of Agricultural Sciences; QIAN, YONGZHONG - Chinese Academy Of Agricultural Sciences

Submitted to: Atomic Spectroscopy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2020
Publication Date: 6/25/2020
Citation: Wang, B., Liu, T., Liu, J., Mao, X., Na, X., Chen, G., Liu, M., Qian, Y. 2020. A novel strategy of anti-interference for solid dilution in elemental analysis using spontaneous surface dispersion theory. Atomic Spectroscopy. 41(3):119-126. https://www.researchgate.net/publication/342639027.
DOI: https://doi.org/10.46770/AS.2020.03.004

Interpretive Summary: Quantitative dilution of solid samples, such as plastic materials, always encounters multifaceted uncertainties. In this work, spontaneous dispersion was applied for the first time to direct sampling in cadmium (Cd)-in-plastic analysis. Ashing, agitation, and heating allowed Cd to disperse evenly on alumina supports. Coupled with atomic fluorescence spectrometry, the proposed method could measure up to >0.3% Cd in plastic samples with <10% reproducibility, and a 9-orders-of-magnitude linear range.

Technical Abstract: Quantitative dilution of solid samples, such as plastic materials, always encounters multifaceted uncertainties. To quickly dilute a solid plastic sample, spontaneous dispersion (SPD) principle previously employed in heterogeneous catalysts synthesis was for the first time applied to direct sampling in Cd analysis. After ashing and agitation, Cd from plastic sample can disperse evenly on a-Al2O3 supports under 600 degree C heating for 30 min. Secondary ion mass spectrometry (SIMS) proved surface concentration of Cd on a-Al2O3 support significantly increased, indicating SPD occurred to Cd. Coupled with solid sampling electrothermal vaporization atomic fluorescence spectrometry (ETV-AFS), the proposed method is capable of measuring up to more than 0.3% Cd in plastic sample with <10% relative standard deviation (RSD), and a pg-mg/g linear range. The measured Cd presence in plastic sample (certified reference materials) by the SPD-ETV-AFS method agreed with the certified values, demonstrating good accuracy and reliability. This SPD dilution method gained reliability, precision, simplicity, and green chemistry advantages. It is highly suitable to heavy metals detection in solid matrices, with the ultimate goals to protect the environment and human health.