Crosslinked Carboxymethyl Konjac Glucomannan Microcolumn Preconcentration of Trace Lead, Cadmium and Copper in Water Samples and Determination by Graphite Furnace Atomic Absorption Spectrometry
CHEN Hao1, SHEN Min1, XUE Ai-fang1, LI Sheng-qing1*, PAN Si-yi2
1. College of Science, Huazhong Agricultural University, Wuhan 430070, China 2. College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
Abstract：A novel solid phase extraction technique was developed for the determination of trace lead, cadmium and copper in environmental water samples based on separation and preconcentration with a microcolumn packed with crosslinked carboxymethyl konjac glucomannan (CCMKGM)prior to its determination by graphite furnace atomic absorption spectrometry. Various influential factors on the separation and preconcentration of lead, cadmium and copper, such as the acidity of the aqueous solution, sample flow rate and volume, and eluent concentration and volume, were investigated systematically, and the optimized operation conditions were established. The analytes could be quantitatively retained by CCMKGM in the pH range of 5.0-7.0, then eluted completely with 1.0 mL 0.5 mol·L-1 HCl. The detection limits(3σ)for analyte ions were 0.038 μg·L-1 for Pb2+, 0.000 5 μg·L-1 for Cd2+ and 0.014 μg·L-1 for Cu2+ with an enrichment factor of 50, and the relative standard deviations were 3.5% for Pb2+, 9.2% for Cd2+ and 4.7% for Cu2+(cPb2+=cCu2+=1.0 μg·L-1; cCd2+=0.1 μg·L-1, n=11). The proposed method was successfully applied to the determination of trace lead, cadmium and copper in environmental water samples (local tap water and lake water). In order to validate the method, the developed method was applied to the determination of lead, cadmium and copper in environmental water reference materials (ERMs, GSBZ 50009-88, P.R. China), and the results obtained were in good agreement with the certified values.
[1] Korn M d G A, Andrade J B d, Jesus D S d, et al. Talanta, 2006, 69: 16. [2] Umashankar V, Radhamani R, Ramadoss K, et al. Talanta, 2002, 57: 1029. [3] Shan H X, Li Z J, Li M. Microchim. Acta, 2007, 159:95. [4] Pereira M D, Arruda M A Z. Microchim. Acta, 2004, 146: 215. [5] Bezerra M A, Arruda M A Z, Ferreira S L C. Appl. Spectrosc. Rev., 2005, 40: 269. [6] XIE Fa-zhi, ZHANG Jun-tang, TANG Hai-ou(谢发之, 张俊唐, 唐海鸥). Chinese Journal of Analytical Chemistry(分析化学), 2006, 34: 1429. [7] Li B, Xie B J. Journal of Applied Polymer Science, 2004, 93: 2775. [8] QIAN Sha-hua, XIANG Luo-jing, DENG Hong-bing, et al(钱沙华, 向罗京, 邓红兵，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2007, 27(3): 592. [9] XUE Ai-fang, CHEN Hao, LUO Xing-cai, et al(薛爱芳, 陈 浩, 罗兴才，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2005, 25(9): 1514. [10] Qian S H, Xue A F, Xiao M, et al. Journal of Applied Polymer Science, 2006, 101: 432. [11] Niu C M, Wu W H, Wang Z, et al. Journal of Hazardous Materials, 2007, 141: 209. [12] Duran C, Gundogdu A, Bulut V N, et al. Journal of Hazardous Materials, 2007, 146: 347. [13] Prasad K, Gopikrishna P, Kala R, et al. Talanta, 2006, 69: 938. [14] SUN Jian-min, XU Peng, SUN Han-wen(孙建民, 徐 鹏, 孙汉文). Chinese Journal of Analytical Chemistry(分析化学), 2004, 32(10): 1356. [15] El-Sheikh A H, Sweileh J A, Al-Degs Y S. Analytica Chimica Acta, 2007, 604: 119.
