Carmoisine Research Articles

Facile synthesis of CQD/g-C3N4 as a highly effective metal-free photocatalyst for the degradation of carmoisine and indigo carmine dye

The development of extensive dye pollution in the water ecosystem seriously endangers the health of the living organism. For effectively eradicating dyecontaminants from water bodies, photocatalysis is consideredan effective, energy-consumption, inexpensive disinfection technique. As an alternative to conventional metal-based catalysts, heterogeneous metal-free photocatalysts are more sustainable and kinder to the environment. Here, we reported the simplehydrothermalchemical production of Carbon Quantum dots (CQD)-doped graphitic carbon nitride(GCN). Analytical instruments such as XRD, SEM, FE-SEM, HR-TEM, EDX, FT-IR, thesurface area of BET analysis, photoluminescence, and UV–vis spectroscopy, zeta potentialwere used to characterize the as-prepared CQD doped GCN (CDCN). The degradation studies reveal that the CDCN catalyst displays the highest rate of degradation performance than pure GCN. Within 60 min, it shows 96 % degradation toward indigo Carmine (IC) and 93 % decomposition towards carmoisine dye (CM). Significant e−/h+ separation, an increased surface area, and a high redox potential capacity to induce charge bears may all contribute to the CDCN catalyst’s enhanced photocatalytic degradation efficiency. The efficiency of the photocatalytic process was optimized by studying and altering many variables. These include Dye concentration, catalyst concentration, and variation of the pH solution were some of these. The nanocomposite exhibited excellent stability after three successive runs of the photocatalytic procedure. According to the kinetics analysis results indicate that the photocatalytic decomposition of Indigo Carmine (IC) and carmoisine (CM) dye follows pseudo-first-order kinetics. For better photodegradation performance, a potential photocatalytic method employing several pairs of electron-hole acceptor scavengershas been put forth. Based on the positionsof the band gap and the result of the characterization, a feasible mechanismpathway for charge carriers was also presented.

Electrochemical Determination of Tartrazine and Carmoisine Dyes from Aqueous Solutions on Modified Electrodes

Introduction: The recognition of the health hazards of azo dyes has highlighted the need to develop efficient, rapid, and reliable analytical methods for dye determination. Method: In this work, electrochemical probing of the azo group of Tartrazine (TZ) and Carmoisine (CR) in food dyes was carried out. Synthesized bismuth and zinc oxide nanoparticles were used to modify Graphite Electrode (GE). Results: Electrochemical analysis showed a much better electrochemical response using ZnO+Bi/GE as a modifier than individually nanoparticle-modified graphite electrodes. From the CV analysis, it was found that both the dyes exhibited irreversible electrochemical behavior, and the redox parameters were calculated. The Limit of Detection (LOD) values recorded for TZ and CR for ZnO+Bi/GEbased sensors were 0.84 uM and 2.80 uM, respectively. The obtained sensitivity values were 11.86 uA/uM/cm2 for TZ and 17.3 uA/uM/cm2 for CR. Conclusion: The sensor evidently demonstrated reliable simultaneous detection of both dyes, making it suitable for practical applications in food safety analysis.

Electrochemical aptasensor based on carboxylated graphene oxide modified carbon paste electrode for strontium ultrasensitive detection

Determination of strontium ions (Sr2+) is crucial with regard to human health and environmental protection. In this work, an electrochemical aptasensor was designed using carboxylated graphene oxide (CGO)-modified carbon paste electrode (CGO/CPE) for ultrasensitive determination of Sr2+ ions. The electrochemical determination was accomplished with employing the constructed G-quadruplex (G4) aptamer at the surface of aptasensor in presence of carmoisine (CA) as an electrochemical label. Moreover, NH2-functionalized aptamer was immobilized onto CGO/CPE via carboxylic group. Hence, differential pulse voltammetry was applied for detection of any possible signal changes of CA on the aptasensor surface. The reduction peak currents of CA in the absence and presence of Sr2+ in solution were different and this difference was linearly dependent to the concentration of Sr2+ in solution. The analytical results revealed that our novel aptasensor showed two appropriate linear ranges (0.1–8.0 pM and 3.0–20.0 nM) versus to Sr2+ ion concentrations with the limit of detection of 0.06 pM (S/N = 3). Excellent stability, selectivity and reproducibility were achieved with this new electrochemical aptasensor. Additionally, the aptasensor showed good achievements in analysis of Sr2+ in aqueous and urine real samples, which making this proposed method a promising candidate for electrochemical detection of Sr2+ in real samples.

Designing a novel DNA-based electrochemical biosensor to determine of Ba2+ ions both selectively and sensitively

This work describes a novel electrochemical biosensor based on G-quadruplex (G4) DNA for the sensitive and selective detection of Ba2+ ions using a Carbon Paste Electrode modified with Ag nanoparticles incorporated in reduced Graphene Oxide via a simple wet chemical method (Ag-rGO/CPE), in the presence of carmoisine (CA) as a new electrochemical indicator. The peak current of CA increased with increasing Ba2+ ions concentration and the DNA-based sensor showed linear ranges of 0.06–0.80 nM and 1.0–80 nM and a Limit of Detection (LOD) of 0.045 nM. The proposed biosensor showed a good selectivity toward Ba2+ ions in the presence of other metal ions such as Ag+, Hg2+, K+ and Na+ and was applied to the analysis of natural samples showing appropriate results.

The protective effect of natural phenolic compound on the functional and structural responses of inhibited catalase by a common azo food dye

In this research retrieval effects of natural yellow (NY) on the performance of carmoisine (CAR) inhibited bovine liver catalase (BLC) was studied using multispectral and theoretical methods. Kinetic studies showed that CAR inhibited BLC through competitive inhibition (IC50 value of 2.24 × 10−6 M) while the addition of NY recover the activity of CAR-BLC up to 82% in comparison with the control enzyme. Circular dichroism data revealed that NY can repair the structural changes of BLC, affected by CAR. Furthermore, an equilibrium dialysis study indicated that NY could reduce the stability of the CAR-catalase complex. The surface plasmon resonance (SPR) data analysis indicated a high affinity of NY to BLC compared to CAR and the binding of NY led to a decrease in the affinity of the enzyme to the inhibitor. On the other hand, fluorescence and molecular docking studies showed that the quenching mechanism of BLC by CAR occurs through a static quenching process, and van der Waals forces and hydrogen bonding play a crucial role in the binding of CAR to BLC. MLSD data demonstrated that NY could increase the binding energy of CAR-BLC complex from −7.72 kJ mol−1 to −5.9 kJ mol−1, leading to complex instability and catalase activity salvage.

Azurobine degradation using Fe2O3@multi-walled carbon nanotube activated peroxymonosulfate (PMS) under UVA-LED irradiation: performance, mechanism and environmental application

Food dyes are a large group of dyes which have been widely used in the food industry. The presence of them in aquatic media results in water pollution. In this work, a heterogeneous photo-assisted peroxymonosulfate (PMS) activation process was used to degrade Azorubine (AZB). Fe2O3 loaded on multi-wall carbon nanotube (Fe@MWCNT) was synthesized and applied to activate PMS under UVA-LED irradiation. Fe@MWCNT catalyst was characterized by XRD, FTIR, EDX-map, BET, FESEM, and TEM analyses. UVA-LED/Fe@MWCNT/PMS process removed around 95% of AZB from aqueous solution under pH= 5, PMS= 1.8 mM, and 130 mg/L Fe@MWCNT. Sulfate radicals showed a higher contribution for AZB degradation compared to hydroxyl radicals and singlet oxygen. Pseudo-first-order model was fitted on AZB degradation with a rate constant of 0.095 min−1. Bicarbonate ions and humic acid had an ultra-inhibitory effect on the oxidative process. Carboxylic acids were monitored during AZB degradation, with the results indicating that aromatic rings of AZB were opened by the attack of sulfate and hydroxyl radicals. Six cycles of the catalyst reuse demonstrated no significant change in the performance of the UVA-LED/Fe@MWCNT/PMS process. The implementation of the UVA-LED/Fe@MWCNT/PMS process was also successfully studied on other food dyes and real wastewater. UVA-LED/Fe@MWCNT/PMS process was an efficient approach for the degradation of organic contaminants in water with high stability.

Optimization of the spontaneous adsorption of food colors from aqueous medium using functionalized Chitosan/Cinnamaldehyde hydrogel

Hydrogels are considered as practical and proficient materials in adsorption and removal of soluble lethal molecules from aqueous system. They are also rapid-decomposable and economical materials besides their diverse preventive claims. In current study, Cinnamaldehyde (C), a natural defensive compound and Chitosan (Ch), natural occurring bio-macromolecule are considered to develop bio-inspired hydrogel (ChC). The structural and surface characteristics of ChC (13C solid state NMR, FT-IR, UV–Vis and SEM) are investigated to confirm the successful grafting. The origami of gelation in ChC performs an excellent adsorption activity towards food dyes, Carmoisine (CA) and Tartrazine (TA), which are contaminated by the accumulation during excess release from catering and chemical industries in aqueous system. The adsorption performance is thoroughly screened by varying the pH, ChC dosage, dye concentration, contact time and temperature in aqueous system. Thermodynamic and Kinetics study suggest the natural tendency of adsorption with a good reusability up to 3 cycles. The main mechanism for spontaneous adsorption is initiated by capturing of TA/CA in porous surface followed by the ionic interactions and formation of H-bondings. ChC based adsorption is an excellent and potential approach to control the toxicants for the water-pollution and water-preservation.

Assessment of the use of boron-doped diamond electrode for highly sensitive voltammetric determination of the azo-dye carmoisine E−122 in food and environmental matrices

A new protocol for the analysis of the azo-dye carmoisine (CMS) is presented by coupling differential pulse voltammetry (DPV) with a cathodically pretreated boron-doped diamond electrode (CPT-BDDE), in phosphate buffer solution (pH 2.0). The CMS presented diffusion-controlled oxidation and reduction peaks at +0.88 and −0.15 V vs Ag/AgCl, respectively. The effect of the pretreatment conditions, pH, and supporting electrolytes were evaluated to the voltammetric determination of CMS. Under optimized conditions, the differential pulse voltammetric signals for CMS were linear over the concentration range of 0.059–1.31 μmol L−1 and 0.010–0.079 μmol L−1 with limits of detection of 7.0 and 3.0 nmol L−1, for the anodic and cathodic processes respectively. The method was precise for CMS determination (RSD < 5.0%) and selective against other dyes. The developed protocol was successfully applied in the analysis of CMS in surface water and foodstuffs with accurate results in comparison with those obtained using a validated spectrophotometric method.

DEVELOPMENT OF INDICATOR FOR ON-SITE DETECTION OF BROMATE IN SOME BREAD SAMPLES IN ABEOKUTA METROPOLIS

A new highly selective indicator, Chitosan-Silver Carmoisine (CTS-AgCAM) was developed for the detection of potassium bromate in bread. The detection was based on the oxidation of Carmoisine (CAM) by potassium bromate (KBrO3), catalysed by Silver Nanoparticles (AgNPs). The CTS-AgNPs was prepared by the reaction of silver nitrate with sodium hydroxide and stabilised in chitosan (CTS) and further addition of CAM. Batch experiments were carried out on various concentration of KBrO3 to obtain optimal conditions for the use of the indicator. This was monitored with a UV-Vis Spectrophotometer. Fifty bread samples were then collected randomly from five different bakeries within Abeokuta, Ogun state, Nigeria and qualitative analysis was carried out on the bread samples using the prepared indicator. The UV-Vis spectrum of the CTS- AgNPs revealed surface plasmon absorption maxima at 418-420 nm while the indicator showed maximum absorption at 516 nm. From the qualitative analysis, it was observed that on addition of 2 drops of CTS-AgCAM to a bread sample solution containing KBrO3, a pink colour of the indicator disappeared. It was also observed from the result of quantitative analysis that the fifty bread samples analyzed all containedKBrO3with concentration ranging between 3.23 ± 0.08 and 6.29 ± 0.91 µg/g. The indicator worked best between 1 and 5 µg/g and had a detection limit of 1 µg/g. The result showed that this indicator can be used easily for efficient on-site detection of bromate in bread.

Cloud Point Extraction and Simultaneous Spectrophotometric Determination of Allura Red and Carmoisine using Wavelet Orthogonal Signal Correction–Partial Least Squares Method

This study presents a simple, safe, cheap, and efficient cloud point extraction method for the simultaneous pre-concentration and determination of Allura Red (AR) and Carmoisine (CA) in food samples. Wavelet orthogonal signal correction was applied to denoise the spectrophotometric data and in combination with partial least squares regression was used to determine each compound simultaneously after cloud point extraction. The effects of different variables on the extraction of both dyes were investigated and optimized. Calibration graphs were linear in the range of 0.06 to 2.0 µg/mL for AR and 0.05 to 1.5 µg/mL for CA. Limits of detection for AR and CA were 0.016 and 0.015 µg/mL, respectively. The root mean square error of prediction for AR and CA was 0.014 and 0.024 µg/mL, respectively.

A Facile HPLC-PDA Method for Simultaneous Determination of Paracetamol, Methyl Paraben, Sunset Yellow and Carmosine in Oral Suspensions

In the present study, a simple, fast and accurate HPLC-PDA method was developed for the simultaneous determination of paracetamol (PAR), methylparaben (MP), sunset yellow (SSY) and carmoisine (CAR) in oral suspensions. The concentrations of colorants are less than with respect to those of active ingredient and this variation makes process of analysis toublesome. In the developed HPLC method, efficient chromatographic separation was achieved using reversed phase C18 column (4.6 mm x 150 mm x 5 μm particle size) and phosphate buffer solution (pH = 6.5)-acetonitrile mobile phase with a flow rate of 1.6 mL/min in the gradient mode. The eluents were monitored via a PDA detector at 300, 254 and 230 nm. The mean retention times of SSY, PAR, CAR and MP were found to be 1.58, 2.15, 3.81 and 4.42, respectively. The proposed method was validated in accordance with ICH guidelines and it was seen that the method met all requirements in terms of linearity, precision, accuracy and selectivity. The developed method was successfully applied for simultaneous determination of the studied compounds in two commercial oral suspension samples.

Automated solid sample dissolution coupled with sugaring-out homogenous liquid-liquid extraction. Application for the analysis of throat lozenge samples

A novel automated procedure for analysis of solid samples based on the on-line dissolution of solid sample and sugaring-out reagent in water-acetonitrile mixture coupled with sugaring-out homogenous liquid-liquid extraction was developed. The procedure was performed in a mixing chamber of a stepwise injection analysis manifold. The performance of the suggested approach was demonstrated by the determination of 2,4-dichlorobenzyl alcohol, amylmetacresol, Yellow Orange S, Azo Rubine and Ponceau 4R in pharmaceutical samples. After phase separation, the upper acetonitrile phase containing 2,4-dichlorobenzyl alcohol, amylmetacresol and lower aqueous phase containing artificial dyes were sequentially analyzed. Under optimal experimental conditions the linear ranges were found to be 0.1–10mgL−1 for 2,4 dichlorobenzyl alcohol, 0.5–50mgL−1 for amylmetacresol, and 1–100mgL−1 for artificial dyes. The sample throughput was 10h−1. The proposed method was successfully applied for the automated analysis of commercial throat lozenges and the analytical results agreed fairly well with the results obtained by reference HPLC-UV method.

Fast and simultaneous determination of eleven synthetic color additives in flour and meat products by liquid chromatography coupled with diode-array detector and tandem mass spectrometry

In this study, an efficient, fast and sensitive method for the simultaneous determination of eleven synthetic color additives (Allura red, Amaranth, Azo rubine, Brilliant blue, Erythrosine, Indigotine, Ponceau 4R, New red, Sunset yellow, Quinoline yellow and Tartrazine) in flour and meat foodstuffs is developed and validated using HPLC coupled with DAD and MS/MS. The color additives were extracted with ammonia–methanol and was further purified with SPE procedure using Strata-AW column in order to reduce matrix interference. This HPLC–DAD method is intended for a comprehensive survey of color additives in foods. HPLC–MS/MS method was used as the further confirmation and identification. Validation data showed the good recoveries in the range of 75.2–113.8%, with relative standard deviations less than 15%. These methods are suitable for the routine monitoring analysis of eleven synthetic color additives due to its sensitivity, reasonable time and cost.

Simultaneous Determination of Acetaminophen and Synthetic Color(s) by Derivative Spectroscopy in Syrup Formulations and Validation by HPLC: Exposure Risk of Colors to Children.

Color additives are used in pediatric syrup formulations as an excipient; though not pre-requisite, but pediatric syrup formulations are normally colored. An attempt has been made to measure simultaneously the single drug, acetaminophen (AT), along with the colors, carmoisine (CA), erythrosine (ET), and sunset yellow FCF (SSY) added in it by three derivative spectroscopy methods namely, 1st order, ratio, and differential derivative methods. Moreover, evaluation has been made for the exposure assessment of the colors added as excipient because some colors have been reported to cause allergic reactions and hypersensitivity in children. The present methods provide simple, accurate, and reproducible quantitative determination of the drug, AT, along with the color in synthetic mixtures and commercial drug formulations without any interference. The limit of detection varied from 0.0001-0.31 μg/ml while limit of quantification ranged from 0.002-1.04 μg/ml in all the three methods. The calibration curve of all the three derivative methods exhibited good linear relationship with excellent regression coefficients (0.9986-1.000). Both intra-day and inter-day precisions showed %RSD value less than 2% while the percentage recovery was found between 96.8-103.8%. The sensitivity of the proposed methods is almost comparable to HPLC and thus, can be used for determination of drug AT, and color simultaneously in pharmaceutical formulation on routine basis. The present methods also showed that colors like SSY and ET are saturating more than 50% of acceptable daily intake (ADI) value which is alarming and needs to be considered for modification by regulatory authorities to safeguard the health of children.

Photophysical Investigations of Carmoisine Interacting with Conventional Cationic Surfactants Under Different pH Conditions

The present study describes the extent of interactions of an efficient food dye, Carmoisine (CAR), with conventional cationic surfactants, hexadecyltrimethylammonium bromide, and ethylhexadecyldimethylammonium bromide (EHDAB). The study was carried out by quantifying the spectral changes of CAR as a function of premicellar to postmicellar surfactant concentrations at various pH conditions. The quantification of CAR molecules entrapped by cationic micellar systems has been estimated with the help of mathematical models. Binding parameters of each surfactant were calculated using differential spectroscopic method. The enhanced solubilization of dye by switching the pH was observed. In support of the electrostatic forces, the larger and more hydrophobic head group favors the promising solubilization of CAR in the outer region of the micellar interior. These findings extend the proficiency of dye molecule as a reporter for sensing electrostatic environment in lipidic membranes and related organized assemblies.

赤色102号中に微量存在するアゾ化合物の構造解析

Three unknown colors (A1, A2 and A3) in Food red No. 102 (R102) were identified by LC-MS and NMR analysis. Red dye A1 was azo rubine (AZO), which is not designated as a coloring agent in Japan. Red dye A2 was a structural isomer of Fast Red E (FRE), which is also not designated as a coloring agent in Japan. Red dye A3 was predicted to be an overreaction product of R102, possessing the R102 structural framework. Furthermore, AZO, which was assumed to have been produced by dimerization of a diazonium salt used as a synthetic intermediate of R102, was also identified in Food red No. 2 (R2).

赤酢から検出された指定外色素のＬＣ／ＭＳによる確認

Suitable liquid chromatography/mass spetrometry (LC/MS) conditions were examined for Amaranth, Red 2G (R2G), Azo Rubine (Azo), Fast Red E (FRE) and Brilliant Blue FCF, which were detected in Akasu, a red vinegar made in Hong Kong from sake lees, on both thin layer chromatography (TLC) and photodiode array high-performance liquid chromatography (PDA-HPLC). Molecular-related ions for each dye were detected with excellent sensitivity by LC/MS using electro-spray ionization with negative ion mode, capillary voltage 3.00 kV, cone voltage 50 V and desolvation temperature 400 degrees C. LC/MS analysis of refined Akasu under these conditions enabled us to obtain clear mass spectra of R2G, Azo and FRE, which were present at trace levels in the Akasu. The results were consistent with those from TLC and PDA-HPLC. These experiments suggested that LC/MS analysis is applicable for confirmation of dyes in food.

Determination of food dyes in soft drinks containing natural pigments by liquid chromatography with minimal clean-up

The essential aim of this work was the optimisation and characterisation of a method for the determination of five synthetic food colours added to soft drinks with natural colours by liquid chromatography with minimal clean-up. The method is simple, rapid, inexpensive and broadly applicable to soft drinks. The results show that tartrazine (E-102), quinoline yellow (E-104), yellow orange (E-110), azo rubine (E-122) and ponceau (E-124) can be determined at low levels simultaneously. The method was evaluated by constructing calibration lines, measurement of recovery and precision, and the limits of quantification and detection. It involves direct injection of a beverage solution (homogenized and degassed) for reversed-phase HPLC analysis with visible detection at a single wavelength. Synthetic colours determination in soft drinks was not affected by the presence of other natural colours contained in drinks with fruit juice and flavour extracts. The results obtained with the samples confirm that the proposed method works well and is useful for serious control or screening of the addition of synthetic colours in soft drinks; the method is therefore recommended for use by the quality control departments of soft drink producers using synthetic food colours.