Determination of Impurities in K2Cr2O7 by an Inductively Coupled Plasma Spectrometer
LI Yu-ping1,2,ZHANG Yi1*,QI Tao1,LIU Ke-ling1
1. Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080, China 2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China
Abstract:The trace elements Si, Al, Fe, Ca, Mn, Mg, and Cl in the K2Cr2O7 produced by chromate cleaner production were determined by a sequential inductively coupled plasma spectrometer in this paper. Matrix effect was studied and eliminated through matrix matching. The analytical conditions for the elements were optimized. Incident power of the RF generator was 0.95 kW. Pressure of carrier gas flow was 0.13 MPa, and its flow rate was 1.2 L·min-1. Auxiliary gas flow rate was 0.2 L·min-1. The element Cl was indirectly determined by the method of AgCl precipitation. The ion Cl- can be completely precipitated in 6% nitric acid system, and then determined after keeping the solution at 50 ℃ for two hours. The recoveries of the studied impurities range from 95% to 104%, and the relative standard deviations are lower than 4% (n=10). Detection limits of these impurities are in a range 0.000 1%-0.000 01% (w/w). The analytical results of random samples agree well with the results using the standard-adding method, and the relative error varies from -4.27% to +5.26%. The developed method has been applied to the determination of impurities in K2Cr2O7 product with satisfactory results.
[1] ZHANG Yi, LI Zuo-hu, QI Tao et al(张 懿,李佐虎,齐 涛等). The Chinese Journal of Chemistry(化学学报), 1999, 57(3): 258. [2] The Chemical Industrial Standards of the People's Republic of China(中华人民共和国化工行业标准). Industrial Potassium Dichromate(工业重铬酸钾)HG2324-92. Beijing: Standards Press of China(北京:中国标准出版社),2002. [3] State Environmental Protection Administration(国家环保局). Monitoring Test Method of Water and Waste Water(水和废水监测分析方法),Beijing:China Environmental Science Press(北京:中国环境科学出版社),1998. [4] ZHOU Hai-shou(周海收). Analytical Laboratory (分析试验室), 1999, 18(5): 89. [5] JING Li-jie(景丽洁). Environmental Engineering(环境工程), 1999, 17(6): 60. [6] JIN Man-yi(金曼一). Journal of Hebei Normal University(Natural Science)(河北师范大学学报·自然科学版), 1995, 19(3): 67. [7] SHU Yong-hong, YANG Xiu-hua, LU Zhong-re et al(舒永红,杨秀华,卢中热等). Journal of Instrumental Analysis(分析测试学报), 1997, 16(6): 64. [8] LIU Dongyan, ZHANG Yuan-li(刘东艳,张园力). Chinese Journal of Analytical Chemistry(分析化学), 1996, 24(2): 244. [9] ZHANG Qi-feng, PENG Shan-shan, ZHU Ning, WU Jian-hong, LI Li, HUANG Jian-jun(张齐凤,彭珊珊,朱 宁, 吴建宏,李 丽,黄建军). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2001, 21(2): 237. [10] AODENG Gao-wa, MENG Quan-sheng, SAI Yin(熬登高娃,孟全胜,赛 音). Chinese Journal of Analytical Laboratory(分析试验室), 2002, 21(4): 77. [11] XIAO Guang, LI Ping, ZHANG Yin et al(肖 光,李 萍,张 颖等). Chinese Journal of Spectroscopy Laboratory(光谱实验室), 2002, 19(5): 602. [12] WANG Xiao-jia, WANG Bao-ning(王晓佳,王保宁). Chinese Journal of Analytical Chemistry(分析化学), 2001, 29(2): 142. [13] DONG Shun-fu, ZHU Zhi-guo, LIU Wei-ming, ZHAO Wen-xiu(董顺福,朱志国,刘伟明,赵文秀). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2001, 21(3): 391. [14] DONG Yin-gen, SHEN Hui-jun, SHEN Zhi-wu(董银根,沈惠君,沈志武). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2002, 22(1): 161. [15] ZHANG Gui-guang, HUANG Fen, SUN Xiao-gang(张桂广,黄 奋,孙晓纲). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2000, 20(1): 71. [16] LIU Xin-wen, CUI Su-jun(刘信文,崔素君). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2002, 22(5): 838. [17] Thompson M, Walsh J N(M.汤姆逊,J. N.沃尔什). A Handbook of Inductively Coupled Plasma Spectrometry(ICP光谱分析指南). Beijing: Metallurgical Industry Press(北京:冶金工业出版社), 1991.