5-Br-PADAP-分光光度法测定大米中的微量锌  

Determination of trace zinc in rice by 5-Br-PADAP- spectrophotometry

作　　者：段宁鑫 王浩洋 王孟乐 包晓玉[1] DUAN Ningxin;WANG Haoyang;WANG Mengle;BAO Xiaoyu(School of Chemistry and Phamaceutical Engineering,Nanyang Normal University,Nanyang 473061,China)

机构地区：[1]南阳师范学院化学与制药工程学院,河南南阳473061

出　　处：《南阳师范学院学报》2019年第3期22-25,共4页Journal of Nanyang Normal University

摘　　要：用5-Br-PADAP-分光光度法对大米中微量锌进行了测定.以5-Br-PADAP为显色剂,Triton X-114为表面活性剂,在pH=8的硼酸-氢氧化钠缓冲溶液中,考察了显色剂用量、表面活性剂用量、缓冲液用量及pH等反应条件对测定结果的影响.实验结果表明:Zn^(2+)与5-Br-PADAP形成1∶2型络合物,其稳定常数为6.8×10~8,最大吸收波长为λ=560 nm,吸光度与锌浓度在0.01～0.60μg/mL范围内呈线性关系,其线性回归方程为A=2.046C+0.016 1,相关系数R=0.999 6,相对标准偏差为4.5%,加标回收率在91%～96%之间.This paper studies 5-Br-PADAP and spectrophotometric method for the determination of trace zinc in rice, with 5-Br-PADAP as chromogenic agent, Triton X-114 for the surface active agent, boric acid and sodium hydroxide in pH = 8 in the buffer solution, and the effects of reaction conditions such as the amount of colorant, surfactant, buffer and pH on the determination results are investigated.The results show that: Zn2+forms 1∶2 complex with 5-br-padap, of which the stability constant is 6.8×108, the maximum absorption wavelength is lambda 560 nm, the absorbance is linearly related to the zinc concentration within the range of 0.01 ~ 0.60 μg/mL, the linear regression equation is A=2.046C+0.0161, the correlation coefficient R=0.9996, the relative standard deviation is 4.5% and the standard recovery is 91%~96%.

关 键 词：5-BR-PADAP 分光光度法 锌 大米 

分 类 号：O655.9[理学—分析化学]