基于FeZSM-5催化剂的类Fenton体系氧化降解日落黄FCF研究

采用等体积浸渍法制备FeZSM-5作为异相类Fenton氧化催化剂,使用XRD、FT-IR对FeZSM-5进行表征,探究反应温度、初始pH值、H_2O_2初始浓度、催化剂用量以及铁负载量对FeZSM-5催化H_2O_2氧化降解日落黄FCF脱色的影响,考察催化剂循环使用性能。结果表明,铁以Fe_2O_3形态存在于分子筛孔道内; FeZSM-5催化剂活性受反应温度影响较大,在最适宜条件下,铁负载质量分数为3.5%的FeZSM-5催化剂在FeZSM-5/H_2O_2类Fenton氧化反应体系中对日落黄FCF模拟废水脱色率达97.0%,且循环使用性能较好。     

分光光度法快速检测饮料中日落黄的研究

采用分光光度法测定饮料中的日落黄,确定了日落黄的最大吸收波长,结果表明:日落黄的最大吸收波长为482 nm,线性回归方程为:y=33.055x+0.0024,线性相关系数r=0.9998,测定饮料中日落黄含量为0.06418 mg/mL,精密度好,相对标准偏差(RSD)为0.15%,在饮料中的加标回收率在96.83%～...     

日落黄的提取和检测方法研究

日落黄是一种常见的人工食用色素,用量受到严格控制。但是近年来日落黄滥用的现象屡见不鲜,因此,研究出能够快速、准确检测日落黄的方法具有重要意义。本文介绍了紫外分光光度法、荧光光谱法、TLC、HPLC、HPLC-MS、UHPLC-MS/MS方法在鉴别和测定中的应用。     

双波长分光光度法同时测定日落黄与柠檬黄

采用双波长分光光度法同时测定食品中日落黄与柠檬黄,其标准曲线的相关系数为r柠＝0．9999,r日＝0．9998,平均回收率也符合要求,该方法简便,所使用仪器普遍。     

三乙烯四胺/丁二酸酐修饰啤酒废酵母菌吸附日落黄的研究

啤酒废酵母菌经戊二醛交联、丁二酸酐接枝后,再经三乙烯四胺修饰,制得了新的生物吸附剂,即三乙烯四胺/丁二酸酐修饰酵母菌,用红外光谱对其进行了表征。结果表明,在溶液pH值为2.0的条件下,修饰酵母菌对日落黄的吸附快速趋于平衡,且不受温度的影响,吸附过程符合准二级动力学方程,吸附模式为Langmuir单分子层吸附;修饰酵母菌吸附日落黄的性能明显优于未修饰酵母菌,修饰酵母菌和未修饰酵母菌对日落黄的最大吸附量分别为935 mg.g-1和250 mg.g-1,前者是后者的3.74倍。     

The study of Sunset Yellow anionic dye interaction with gemini and conventional cationic surfactants in aqueous solution

In the present study, the interaction of an anionic azo dye, Sunset Yellow, with two cationic gemini surfactants with different spacer lengths (s = 3, 6 methylene groups) and their monomeric counterpart, dodecyl trimethyl ammonium bromide (DTAB), was investigated by surface tension, UV–Vis spectroscopy, and zeta potential measurements. The critical micelle concentration (CMC) was determined from plots of the surface tension (γ) as a function of the logarithm of total surfactant concentration. Moreover, the values of binding constants (K_b) of dye-surfactant complexes were calculated by UV–Vis spectroscopy. The UV–Vis spectra showed that the dye–surfactant interaction occurred in the solution at concentrations far below the CMC of each surfactant. The gemini surfactant with a shorter spacer showed stronger interaction with dye in comparison to DTAB and the gemini with longer spacer. The effect of surfactant chemical structure on solubilization of dye-surfactant aggregates at surfactant concentration above CMC was investigated by zeta potential.     

Physicochemical investigation and spectral properties of Sunset Yellow dye in cetyltrimethylammonium bromide micellar solution under different pH conditions

To mimic binding to biological membranes, the extent of interaction of the efficient food dye Sunset Yellow with a cationic surfactant, cetyltrimethylammonium bromide, was probed by quantifying its absorption and fluorescence emission spectra as a function of premicellar to post‐micellar surfactant concentration. The characteristics of the partition behaviour and spectral‐luminescent properties of Sunset Yellow–surfactant have been evaluated qualitatively as well as quantitatively for various cetyltrimethylammonium bromide concentrations. With the help of mathematical models, the water–micelle partition coefficient, the Sunset Yellow–cetyltrimethylammonium bromide binding constant, the binding capacity, and the degree of counterion binding were calculated at 25 °C under various pH conditions. The solubilisation of Sunset Yellow is also discussed from the thermodynamics viewpoint by considering the standard free energy change of dye solubilisation and the Sunset Yellow–cetyltrimethylammonium bromide binding energy. The high values of all these interactions indicate that the dye, being organic in nature, is partitioned largely from the aqueous environment to the palisade layer of the micelle. The solubilisation of the dye is enhanced by switching the pH to suppress the self‐aggregation of dye molecules. Combined with electrostatic forces, the hydrophobic interactions also play a promising role in the solubilisation of Sunset Yellow in the outer core of the micellar interior.