title: Evaluation of flow injection-solution cathode glow discharge-atomic emission spectrometry for the determination of major elements in brines.
abstract: A new method for the determination of major metal elements in high salinity brines was developed by solution cathode glow discharge (SCGD) with flow injection analysis (FIA). The matrix interferences of major cations and anions in brines have been evaluated. It was found that high concentration of Na(+) and K(+) could interfere each other, K(+) at a concentration of 400mgL(-1) enhanced the signal intensity of Na(+) more than 20%. The effect of the anions was observed and it was noted that the signal intensity of both Ca(2+) and Mg(2+) were suppressed significantly when the SO4(2-) reached 100mgL(-1). It was demonstrated that some low molecular weight organic substances such as formic acid, glycerol and ascorbic acid could eliminate interference of SO4(2-) even with volume percentages of 0.5%. Under the optimized condition, the proposed FIA-SCGD can determine K, Na, Ca and Mg with the limits of detection of 0.49 (K), 0.14 (Na), 11 (Ca) and 5.5 (Mg) ngmL(-1). The proposed method has been successfully applied to the analysis of 5 salt lake samples and compared with those obtained with inductively coupled plasma atomic emission spectrometry (ICP-AES). The advantages of small size, low energy consumption, good stability and repeatability indicated that the SCGD is promising for the determination of major ions in brine samples.
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; Suzhou Auto Testing Technology Services Co., LTD., Suzhou 215134, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Zhenli
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Lanlan
authors.initials: L
authors.lastname: Jin
authors.affiliation: Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Department of Earth Sciences, Oxford University, Oxford OX1 3PR, UK.
authors.forename: Nicholas Stanley
authors.initials: NS
authors.lastname: Belshaw
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Shenghong
authors.initials: S
authors.lastname: Hu
keywords: Brines; Interference; Liquid discharge; Organic substance