Study on synthesis of 2-(5-nitro-2-pyridylazo)-4,5-dimethylphenol and its color reaction with cobalt (Ⅱ)
HAN Quan*1,2, GAO Mei-juan2, WANG Rui1, TIAN Li2 , YANG Xiao-hui1
1. Department of Chemistry and Chemical Engineering, Xi′an University of Arts and Science,Xi'an 710065, China；2. College of Chemistry and Chemical Engineering,Yan′an Universty, Yan′an 716000, China
Abstract：A new pyridine-azo reagent called 2-(5-nitro-2-pyridylazo)-4,5-dimethylphenol (5-NO2-PADMP) was synthesized and identified by elemental analysis and infrared spectrum. Its coloring reaction with cobalt was also systematically studied. The results showed that in the presence of cationc surfactant cetyl trimethyl ammonium bromide (CTMAB), 5-NO2-PADMP could react with cobalt to form stable blue-green complex in H3BO3-Na2B4O7 buffer solution at pH 8.5-9.5, which had maximum absorption peak at 731 nm. The contrast (△λ) was 124 nm, and the apparent molar absorbtivity wasε731=2.02×104 L·mol-1·cm-1. Beer's law was obeyed for cobalt in the range of 0-2.0 μg/mL. The proposed method was simple, convenient and fast. It had been applied to the determination of cobalt in molecular sieve catalyst with satisfactory results.
韩权*，高美娟，王睿，田丽，杨晓慧. 2-（5-硝基-2-吡啶偶氮）-4,5二甲基苯酚的合成及其与钴(Ⅱ)显色反应的研究[J]. 冶金分析, 2011, 31(5): 41-44.
HAN Quan*, GAO Mei-juan, WANG Rui, TIAN Li, YANG Xiao-hui. Study on synthesis of 2-(5-nitro-2-pyridylazo)-4,5-dimethylphenol and its color reaction with cobalt (Ⅱ). , 2011, 31(5): 41-44.
