Review—Recent Trends on the Electrochemical Sensors Used for the Determination of Tartrazine and Sunset Yellow FCF from Food and Beverage Products

Synthetic dyes were widely used in food industry due to the advantages offered, such as good stability to oxygen, light, and pH, reproducibility, bright color, low sensitivity to storage conditions and technological processing, and of course, low cost. Unfortunately, some of them have potential harmful effects on human health (the presence of azo group in the molecular structure of azo dyes has carcinogenic and mutagenic effects in the human health), thus, their detection in various food and beverage products became essential. This review presents the latest development in sensors design used for the determination of two commonly used azo dyes – tartrazine and sunset yellow in real food and beverage samples, revealing that there is a variety of efficient sensors with low limits of detection, wide linear concentration ranges, and high selectivities and sensitivities.

In vitro effects of Sunset Yellow on Chromosomal Damage and Sister Chromatid Exchanges in Human Peripheral Lymphocytes

Sunset Yellow (SY) is an organic azo dye that is used extensively as a coloring agent in many industries, such as cosmetics, pharmaceuticals ,and foodstuffs. Many studies have conflicting results about the genotoxicity effect of SY. Thus, the purpose of this study was to provide additional data concerning SY genotoxicity in human lymphocytes by using chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs) assay. Four concentrations of Sunset Yellow (1, 5, 20 ,and 50 mg/ml) were used on human lymphocyte cultures. Positive and negative controls were mitomycin C and distilled water, respectively. Compared to the control, SY caused a significant increase in CAs and SCEs frequencies at all concentrations. A total of five types of CAs were observed, such as gaps, fragments, RCF, stickiness,and polyploidy. According to the present results, high concentrations of SY are genotoxic in vitro to cultured human lymphocytes. To determine its full genotoxicity potential, SY should be tested in other test systems.

Investigation of the aqueous adsorption capacity of a 6-connected Zr-MOF for anionic and cationic dyes in comparison with other traditional porous materials

A 6-connected Zr-MOF (MOF-808) was successfully synthesized via the solvothermal method with the assistance of formic acid (HCOOH). The resulting MOF showed high crystallinity and thermal stability, which was verified by powder X-ray diffraction (PXRD) measurement, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). As can be expected, the obtained material possessed high porosity with an extremely high specific BET surface area (SABet) of 2372 m2/g. The adsorption capacity of MOF-808 for anionic dyes (i.e. sunset yellow, quinoline yellow, and methyl orange) and cationic ones (i.e. methylene blue and malachite green) in aqueous solutions was respectively investigated. For comparison purpose, the adsorption experiments were also carried out using other traditional porous materials, including commercial microporous activated carbon and synthesized mesoporous SBA-15 with BET surface areas of 1030 m2/g and approximately 800 m2/g, respectively. It was demonstrated that the efficiency of MOF-808 in trapping anionic dyes in water was significantly higher while carbon and silica materials exhibited better performances for the case of cationic dyes.

Optimization of the Sunset Yellow Dye removal by electrocoagulation using response surface method

In recent years, among the various treatment methods, the electrocoagulation process has been used for the treatment of effluents containing various dye pollutants. Sunset yellow (S.Y.) azo dye is one of the common food colors widely used in various food industries. This study investigated the removal of the dye S.Y. from aqueous media by the electrocoagulation method in an electrochemical reactor using concentric iron electrodes. The experiments were designed by the Response Surface Method (RSM) with the help of the Minitab software in such a way that the effect of various process-influencing parameters, such as current density, electrolysis time, electrolyte concentration, pH of the solution, and the effluent flow rate, on the desired pollutant removal efficiency was investigated. According to the results of the process optimization by RSM, the optimal conditions for the process were obtained as follows: pH of 10, current density of 2.65 mA/cm2, electrolysis time of 42.32 min, initial dye concentration of 20 mg/L, and effluent flow rate of 2.5 L/min. Under the above optimal conditions, the efficiency of dye removal was more than 99%.

Quaternization of Poly(2-diethyl aminoethyl methacrylate) Brush-Grafted Magnetic Mesoporous Nanoparticles Using 2-Iodoethanol for Removing Anionic Dyes

Magnetic mesoporous silica nanoparticles (Fe3O4-MSNs) were successfully synthesized with a relatively high surface area of 568 m2g−1. Fe3O4-MSNs were then modified with poly(2-diethyl aminoethyl methacrylate) (PDEAEMA) brushes using surface-initiated ARGET atom transfer radical polymerization (ATRP) (Fe3O4@MSN-PDMAEMA). Since the charge of PDEAEMA is externally regulated by solution pH, tertiary amines in the polymer chains were quaternized using 2-iodoethanol to obtain cationic polymer chains with a permanent positive charge (Fe3O4@MSN-QPDMAEMA). The intensity of the C−O peak in the C1s X-ray photoelectron spectrum increased after reaction with 2-iodoethanol, suggesting that the quaternization process was successful. The applicability of the synthesized materials on the removal of methyl orange (MO), and sunset yellow (E110) dyes from an aqueous solution was examined. The effects of pH, contact time, and initial dyes concentrations on the removal performance were investigated by batch experiments. The results showed that the Fe3O4@MSN-PDMAEMA sample exhibited a weak adsorption performance toward both MO and E110, compared with Fe3O4@MSN-QPDMAEMA at a pH level above 5. The maximum adsorption capacities of MO and E110 using Fe3O4@MSN-QPDMAEMA were 294 mg g−1 and 194.8 mg g−1, respectively.