Ambient-temperature trap/release of arsenic by dielectric barrier discharge and its application to ultratrace arsenic determination in surface water followed by atomic fluorescence spectrometry

Authors: MAO, XUEFEI - Chinese Academy Of Agricultural Sciences; QI, YUEHAN - Chinese Academy Of Agricultural Sciences; HUANG, JUNWEI - Beijing Titan Instruments Co; LIU, JIXIN - Chinese Academy Of Agricultural Sciences; Chen, Guoying; NA, XING - Chinese Academy Of Agricultural Sciences; WANG, MING - Chinese Academy Of Agricultural Sciences; QIAN, YONGZHONG - Chinese Academy Of Agricultural Sciences

Submitted to: Analytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2016
Publication Date: 3/23/2016
Citation: Mao, X., Qi, Y., Huang, J., Liu, J., Chen, G., Na, X., Wang, M., Qian, Y. 2016. Ambient-temperature trap/release of arsenic by dielectric barrier discharge and its application to ultratrace arsenic determination in surface water followed by atomic fluorescence spectrometry. Analytical Chemistry. 88(7):4147-4152. doi: 10.1021/acs.analchem.6b00506.

Interpretive Summary: A novel dielectric barrier discharge reactor (DBDR) was developed to trap/release arsenic in water samples at room temperature, allowing detection of ultratrace arsenic by hydride generation atomic fluorescence spectrometry (HGAFS). Major conditions were investigated and optimized. With 8-fold enrichment, arsenic could be detected as low as one part per trillion (ppt) and linear response in the 50-5000 ppt range. Quantitative recovery (98-103%) was obtained for tap, river, lake, and seawater samples. This method was further validated using 3 certified reference materials.

Technical Abstract: A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HGAFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical method was established for ultratrace arsenic in real samples. Moreover, the effects of voltage, oxygen, hydrogen, and water vapor on trapping and releasing arsenic by DBDR were investigated. For trapping, arsenic could be completely trapped in DBDR at 40 mL/min of O(2) input mixed with 600 mL/min Ar carrier gas and 9.2 kV discharge potential; prior to release, the Ar carrier gas input should be changed from the upstream gas liquid separator (GLS) to the downstream GLS and kept for 180 s to eliminate possible water vapor interference; for arsenic release, O(2) was replaced by 200 mL/min H2 and discharge potential was adjusted to 9.5 kV. Under optimized conditions, arsenic could be detected as low as 1.0 ng/L with an 8-fold enrichment factor; the linearity of calibration reached R(2) > 0.995 in the 0.05 ug/L-5 ug/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 98% to 103%; and the measured values of the CRMs including GSB-Z50004-200431, GBW08605, and BW(E)080390 were in good agreement with the certified values. These findings proved the feasibility of DBDR as an arsenic preconcentration tool for atomic spectrometric instrumentation and arsenic recycling in industrial waste gas discharge.