Novel dielectric barrier discharge trap of arsenic introduced by electrothermal vaporization: the possible mechanism and its application

Authors: GU, SIYU - Chinese Academy Of Agricultural Sciences; HUANG, XUDONG - Beijing Ability Technique Company, Limited; CHEN, MINGLI - Jilin University; LIU, JIXIN - Chinese Academy Of Agricultural Sciences; MAO, XUEFEI - Chinese Academy Of Agricultural Sciences; NA, XING - Beijing Ability Technique Company, Limited; Chen, Guoying; SHAO, YUNBIN - Beijing Ability Technique Company, Limited

Submitted to: Analytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2021
Publication Date: 10/28/2021
Citation: Gu, S., Huang, X., Chen, M., Liu, J., Mao, X., Na, X., Chen, G., Shao, Y. 2021. Novel dielectric barrier discharge trap of arsenic introduced by electrothermal vaporization: the possible mechanism and its application. Analytical Chemistry. https://doi.org/10.1021/acs.analchem.1c03079.
DOI: https://doi.org/10.1021/acs.analchem.1c03079

Interpretive Summary: For the first time gas phase enrichment (GPE) of arsenic (As) was fulfilled based on hyphenation of electrothermal vaporizer (ETV) and dielectric barrier discharge (DBD) reactor. The first DBD tube fulfills effective As atomization; the second DBD tube sequentially fulfills As trapping under oxygen-rich atmosphere and release of As atoms under hydrogen-rich atmosphere. This trap and release cycle separates matrix interference and enhances the sensitivity by atomic fluorescence spectrometry (AFS). The linear dynamic ranges were 2-100 parts per billion (ppb); the limit of detection was 0.08 ppb, and the relative standard deviations were 5-6%. Quantitative recoveries were achieved for laver, kelp, and Undaria pinnatifida samples. This ETV-DBD-AFS method is easy, green, and cost-effective for As analysis in seafood.

Technical Abstract: In this work, a novel dielectric barrier discharge reactor (DBDR) coupled to an electrothermal vaporizer (ETV) was established for arsenic determination. It is the first time the gas phase enrichment (GPE) was fulfilled based on hyphenation of ETV and DBD. Specially, the mechanism of arsenic vaporization, transportation, trap, and release was investigated via X-ray photoelectron spectroscopy (XPS) and other approaches. The new-designed 1st DBD tube prior to air inlet fulfills atomization of arsenic nanoparticles in vaporized aerosol leading to sufficient yield of free arsenic atoms that are indispensable for forming arsenic oxides in the 2nd DBD; the 2nd DBD tube enables trap of arsenic oxides and release of arsenic atoms under O2- and H2-dominating atmospheres, respectively. As a result, the trap and release of arsenic separates matrix interference and enhances the analytical sensitivity. Under the optimized conditions, the linear dynamic ranges (R2>0.995) were 2-100 µg/L; the method limit (LOD) was 0.08 µg/L and the relative standard deviations (RSDs) were within 6% for As standard solution and within 5% for real seafood samples, indicating adequate analytical sensitivity and precision. The mean spiked recoveries for laver, kelp, and Undaria pinnatifida samples were 95-110%; and the results of the certified reference materials (CRMs) were consistent with the certified values. This ETV-DBD-AFS scheme is easier, greener, and low-cost for As analysis in real seafood samples. These results proved the feasibility of DBD as a novel transportation enhancement and preconcentration tool for arsenic, revealing its promising potential in the development of fast analytical instrumentation based on direct solid sampling ETV.