Preconcentration of Trace Cu(Ⅱ) in Water Samples with Nano-Sized ZnO and Determination by GFAAS
HUANG Si-si, ZHANG Xu, QIAN Sha-hua*
School of Resources and Environmental Science, Hubei Biomass-Resource Chemistry and Environmental, Biotechnology Key Laboratory, Wuhan University, Wuhan 430079，China
Abstract：The content of copper in natural water is very low, and direct determination is difficult. Therefore, it is very meaningful for the combination of efficient separation-enrichment technology and highly sensitive detection. Based on the high adsorption capacity of Cu(Ⅱ) onto nano-sized ZnO, a novel method by using nano-sized ZnO as adsorbent and graphite furnace atomic absorption spectrometry as determination means was in this work. The adsorption behaviors of Cu(Ⅱ) on nano-sized ZnO was studied. Effects of acidity, adsorption equilibrium time, adsorbent dosage and coexisting ions on adsorption rates were investigated. The results showed that the adsorption efficiency was above 95% in a pH range from 3.0 to 7.0. Compared with other adsorbents for trace element enrichment such as activated carbon, nano-sized TiO2 powder, the most prominent advantage is nano-sized ZnO precipitate with the concentrated element can directly dissolved in HCl solution without any filtration and desorption process can directly analyzed by graphite furnace atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. Compared with colloid nano materials, nano-sized ZnO is the true solution after dissolving have small matrix effect and viscosity more suitable for graphite furnace atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry detection. The proposed method possesses low detection limit (0.13 μg·L-1) and good precision (RSD=2.2%). The recoveries for the analysis of environmental samples were in a rang of 91.6%～92.6% and the analysis results of certified materials were compellent by using the proposed method.
[1] Prohaska J R. Advances in Nutrition, 2011, 2(2): 89. [2] Davies K M, Hare D J, Cottam V. Metallomics, 2013, 5(1): 43. [3] Babich P S, Skvortsov A N, Rusconi P. Cancer Biology & Therapy，2013, 14(7): 614. [4] Xing W, Huang W M, Liu G H. Environmental Toxicology，2010, 25(2): 103. [5] Kondera E, Lugowska K, Sarnowski P. Fish Physiology and Biochemistry，2014, 40(1): 9. [6] State Environmental Protection Administration of China(国家环境保护总局). Analysis Methods for Water and Waste Water, Forth Edition.(水和废水监测分析方法, 第4版). Beijing: China Environmental Science Press(北京：中国环境科学出版社). 2002. [7] TAN Shu-hua, OUYANG Ming(谭树华，欧阳铭). Acta Agriculturae Jiangxi(江西农业学报)，2010，22(11): 139. [8] CHEN Xue-yun, LIU Li-ping(陈雪云，刘丽萍). World Sci-Tech R & D(世界科技研究与发展), 2008, 30(2): 143. [9] Li Z H, Li J W, Wang Y B. Spectrochimica Acta Part A-Molecular And Biomolecular Spectroscopy，2014, 117: 422. [10] Qian S H, Zhang S J, Huang Z. Microchimica Acta，2009, 166(3-4): 251. [11] LI Li, WANG Ya-ping, DING Ya-ping(李 丽，王雅萍，丁亚平). Journal of Functional Materials and Devices(功能材料与器件学报)，2011, 17(6): 533. [12] PENG Hong, ZHANG Xu(彭 虹，张 旭). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2013, 33(3): 822. [13] Xu S X, Zheng M L, Zhang X F. Microchemical Journal，2012, 101: 70. [14] Xiang L J, Zhang X, Lu M. Journal of Analytical Atomic Spectrometry，2012, 27: 359. [15] Fu J Q, Zhang X, Qian S H. Talanta，2012, 94: 167.
