Environmental influences on the measurement of dissolved arsenic using Zr-oxide DGT
SUN Qin1, Xü Lü1, DING Shi-ming2, CHEN Jing1, ZHANG Li-ping1
1. Key laboratory of Integrated Regulation and Resources Development of Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China;
2. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
Influences of environmental factors on the measurement of dissolved arsenic (As) using Zr-oxide diffusive gradient in thin films technique (Zr-oxide DGT) were systematically investigated in the laboratory, and this technique was applied for in situ determination of dissolved As in natural water. After 16-d exposure of numerous inorganic anions, the presence of SO42- had no influence on the measurement of As using Zr-oxide DGT, while HCO3-, Cl-, SiO32- and humic acid had negative effects, with the largest tolerant concentrations of 360mg/L, 45g/L, 100mg/L and 36mg/L, respectively. The dynamical uptake showed that there were no influences of HCO3-(37~148mg/L), SO42-(1.44~2.88g/L), Cl-(12~24g/L), SiO32-(8~24mg/L) and humic acid (3~9mg/L) with the exposure time span from 1 to 4d, while the uptake of As to Zr-oxide DGT, particularly As (III), were inhibited by high concentrations of HCO3-(370mg/L), SO42-(8.64g/L), Cl-(72g/L) and humic acid (27mg/L) at the exposure time of 3~4d, and SiO32-(72mg/L) at the exposure time of 2~4d. The Zr-oxide DGT sampling technique was applied to water in Nanjing City in comparison with the conventional monitoring technique. The DGT-measured concentrations of dissolved As were in line with those by the conventional monitoring technique.
Straif K, Benbrahim-Tallaa L, Baan R, et al. A review of human carcinogens aPart C: metals, arsenic, dusts, and fibres [J]. The Lancet Oncology, 2009,10:453-454.
[2]
Mohan D, Pittman Jr C U. Arsenic removal from water/ wastewater using adsorbents—A critical review [J]. Journal of Hazardous Materials, 2007,142:1-53.
[3]
Davison W, Zhang H. In-situ speciation measurements of trace components in natural waters using thin film gels [J]. Nature, 1994,367:546-548.
[4]
Zhang H, Davison W, Gadi R, Kobayashi T. In situ measurement of dissolved phosphorus in natural waters using DGT [J]. Analytica Chimica Acta, 1998,370:29-38.
[5]
Luo J, Zhang H, Santner J, et al. Performance characteristics of diffusive gradients in thin films equipped with a binding gel layer containing precipitated ferrihydrite for measuring arsenic (V), selenium (VI), vanadium (V), and antimony (V) [J]. Analytical Chemistry, 2010,82:8903-8909.
[6]
Bennett W W, Teasdale P R, Panther J G, et al. New diffusive gradients in a thin film technique for measuring inorganic arsenic and selenium (IV) using a titanium dioxide based adsorbent [J]. Analytical Chemistry, 2010,82:7401-7407.
[7]
Sun Q, Chen J, Zhang H, et al. Improved diffusive gradients in thin films (DGT) measurement of total dissolved inorganic arsenic in waters and soils using a hydrous zirconium oxide binding layer [J]. Analytical Chemistry, 2014,86(6):3060-3067.
[8]
Sun Q, Chen Y F, Ding S M, et al. Investigation of potential interferences on the measurement of dissolved reactive phosphate using zirconium oxide-based DGT technique [J]. Journal of Environmental Sciences, 2013,25(8):1592-1600.
[9]
Panther J G, Stillwell K P, Powell K J, et al. Development and application of the diffusive gradients in thin films technique for the measurement of total dissolved inorganic arsenic in waters [J]. Analytica Chimica Acta, 2008,622:133-142.
[10]
Price H L, Teasdale P R, Jolley D F. An evaluation of ferrihydrite-and Metsorb-DGT techniques for measuring oxyanion species (As, Se, V, P): Effective capacity, competition and diffusion coefficients [J]. Analytica Chimica Acta, 2013,803: 56-65.
[11]
Zhang H, Davison W. Performance characteristics of diffusion gradients in thin films for the in situ measurement of trace metals in aqueous solution [J]. Analytical Chemistry, 1995,67:3391-3400.
[12]
Ding S M, Xu D, Sun Q, et al. Measurement of dissolved reactive phosphorus using the diffusive gradients in thin films technique with a high-capacity binding phase [J]. Environmental Science & Technology, 2010,44:8169-8174.
[13]
Grasshoff K, Ehrhardt M, Kremling K, et al. 3rd ed.; Methods of Seawater Analysis [M]. Wiley-VCH New York, 1999.
Bennett W W, Teasdale P R, Panther J G, et al. Speciation of dissolved arsenic by diffusive diffusive gradients in thin films: selective binding of As (III) by 3-Mercaptopropyl-functionalized Silica gel [J]. Analytical Chemistry, 2011,83:8293-8299.
[16]
Bortun A, Bortun M, Pardini J, et al. Effect of competitive ions on the arsenic removal by mesoporous hydrous zirconium oxide from drinking water [J]. Materials Research Bulletin, 2010,45: 1628-1634.
[17]
Chitrakar R, Tezuka S, Sonoda A, et al. Selective adsorption of phosphate from seawater and wastewater by amorphous zirconium hydroxide [J]. Journal of Colloid and Interface Science, 2006,297:426-433.
[18]
Smedley P L, Kinniburgh D G. A review of the source, behaviour and distribution of arsenic in natural waters [J]. Applied Geochemistry, 2002,17:517-568.
[19]
Panther J G, Teasdale P R, Bennett W W, et al. Comparing dissolved reactive phosphorus measured by D G T with ferrihydrite and titanium dioxide adsorbents:anionic interferences, adsorbent capacity and deployment time [J]. Analytica Chimica Acta, 2011,698:20-26.
[20]
Drever J I.The geochemistry of natural waters:Surface and Groundwater Environments [M]. 3rd. ed., Prentice Hall, New Jersey, 1997.
Warnken K, Zhang H, Davison W. Accuracy of the diffusive gradients in thin-films technique: Diffusive boundary layer and effective sampling area considerations [J]. Analytical Chemistry, 2006,78:3780-3787.
