Determination of Trace Lead in Water by UV-Visible Diffuse Reflectance Spectroscopy Combined with Surfactant and Membrane Filtration-Enrichment
ZHANG Xiao-fang, ZHU Bi-lin, LI Wei, WANG Lei, ZHANG Lei, WU Ting, DU Yi-ping*
Shanghai Key Laboratory of Functional Materials Chemistry, and Research Centre of Analysis and Test, East China University of Science and Technology, Shanghai 200237, China
Abstract:In this paper, a method of determination of trace lead in water by UV-Visible diffuse reflectance spectroscopy combined with surfactant and membrane filtration enrichment was proposed. In the NH3·H2O-NH4Cl buffer solution with pH 8.5, the lead(Ⅱ) ion would react with dithizone to form the red complex under vigorous stirring, which is hydrophobic and can be enriched by the mixed cellulose ester membrane. In addition, the nonionic surfactant Polyoxyethylene lauryl ether (Brij-30) was added into the solution to improve the enrichment efficiency, then visible diffuse reflectance spectra of the membrane were measured directly after the membrane were naturally dried. We also optimized the reaction conditions which may affect the complexation reaction process, such as type of surfactants, the concentration of the surfactant, the reaction acidity, the concentration of dithizone as well as the reaction time. The research results show that under the optimum conditions, a good linear correlation between absorbance at 485 nm and concentration of lead in the range of 5.0~100.0 μg·L-1 was obtained with a squared correlation coefficient (R2) of 0.990 6, and the detection limit was estimated accordingly to be 2.88 μg·L-1. To determine real water sample, the interference from some potential coexisting ions was also studied at the optimal conditions when the concentration of lead(Ⅱ) ion standard solution was fixed to 20 μg·L-1. The results indicate that the following ions cannot interfere in the determination of lead with the proposed method: 500 times of the K+,Na+,Ca2+,Mg2+,NH+4,NO-3,Cl-,CH3COO-, SO2-4; 10 times of the Al3+(using 10% NaF as a masking reagent to avoid the interference); 10 times of the Fe3+ (using 10 % NaF and 10% sodium potassium tartrate as masking reagents); 10 times of Hg2+ or Zn2+ (using 10% NaSCN and 10% potassium sodium tartrate as masking reagents); the same amount of Cd2+,Cu2+. The proposed method was applied to the determnation of lead(Ⅱ) in bottled water as a real sample. The determination results show good agreements between the proposed method and graphite furnace atomic absorption spectrometry(GFAAS) method. The recoveries in case of spiked real samples were between 95.4% and 104.5%, and the standard deviations(SD) were between 0.5 μg·L-1 and 1.5 μg·L-1,which indicate that the method developed in the present work with advantages of accuracy, simpleness, sensitiveness are of potential application for the determination of trace lead in water samples.
张晓芳,朱碧琳,李 炜,王 蕾,张 磊,吴 婷,杜一平* . 表面活性剂-膜富集-紫外可见漫反射光谱法测定水中的痕量铅 [J]. 光谱学与光谱分析, 2015, 35(07): 1944-1948.
ZHANG Xiao-fang, ZHU Bi-lin, LI Wei, WANG Lei, ZHANG Lei, WU Ting, DU Yi-ping* . Determination of Trace Lead in Water by UV-Visible Diffuse Reflectance Spectroscopy Combined with Surfactant and Membrane Filtration-Enrichment. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2015, 35(07): 1944-1948.
[1] Stephani Kim, Monica Arora, Cristina Fernandez, et al. Environmental Research, 2013, 126: 105. [2] Tasneem Gul Kazi, Faheem Shah, Hassan Imran Afridi, et al. Environmental Toxicology and Pharmacology, 2013, 36(3): 858. [3] Watanbe T, Nakatsuka H, Shimbo S, et al. International Archives of Occupational and Environmental Health, 2013, 86(8): 865. [4] GB5749—2006, Standard for Ddrinking Water Quality. National Standards of the People’s Republic of China(生活饮用水卫生标准). [5] Zeid A Alothman, Erkan Yilmaz, Mohamed Habila, et al. Microchim Acta, 2013, 180: 669. [6] Wang Yukun, Gao Shutao, Zang Xiaohuan, et al. Analytica Chimica Acta, 2012, 716: 112. [7] Zougagh M, Garcia A de Torres, Vereda E Alonso, et al. Talanta, 2004, 62(3): 503. [8] Jasmina Djedjibegovic, Thorjrn Larssen, Armin Skrbo, et al. Food Chemistry, 2012, 131(2): 469. [9] Juliana A Nunes, Bruno L Batista, Jairo L Rodrigues, et al. Journal of Toxicology and Environmental Health, 2010,73(13-14): 878. [10] GB 5009.12—2010. Determination of Lead in Foods. National Standards of the People’s Republic of China(食品中铅的测定). [11] Humaira Khan, Jamaluddin Mahmed, Iqbal M Bhanger. Analytical Sciences, 2007, 23: 193. [12] Yin Changhai, Jibran Iqbal, Hu Huilian, et al. Journal of Hazardous Materials, 2012, 233-234: 207. [13] Jibran Iqbal, Yin Changhai, Geng Jinpei, et al. Microchim. Acta, 2012, 177: 195. [14] Katsumi Goto, Shigeru Taguchi. Analytical Sciences, 1993, 9(3): 1. [15] LIU Cheng(刘 程). Applications of Surfactants(表面活性剂应用大全). Beijing: Beijing Industrial University Press(北京: 北京工业大学出版社), 1994. 52.