Lemon Yellow Research Articles

Emissive glutathione modified sulphur quantum dots for the sensing of lemon yellow and luminescent hydrogels/films

Lemon yellow (LY) is an azo dye which is widely used as food colorant. The continuous consumption can result in the safety concerns for both human and environmental health. This study describes a new sulphur quantum dot (SQD) based fluorescent sensor, which was facilely prepared with oxidized-glutathione (GSSG) as passivator at mild condition of 75 °C. The obtained sulphur quantum dots (GSSG-SQDs) have a relative quantum yield of 0.25, which is 2–5 times that of most SQDs. GSSG-SQDs were used as a sensor for lemon yellow in the concentration range of 0.10–70 μM and the limit of detection of 60 nM. The application was verified with the real sensing of lemon yellow in the soft drinking and tap water, having the standard recovery from 92.5 % to 105 %. Given the great luminescence and photostability, GSSG-SQDs were used as a filler for the preparation of luminescent films and hydrogels as a promising material for a wide range of applications such as information encryption and bioengineering.

Green one-step synthesis of N-doped carbon quantum dots for fluorescent detection of lemon yellow in soft drinks

A new fluorescent sensor for the determination of lemon yellow was developed based on nitrogen-doped carbon quantum dots (N-CQDs), which were prepared via a hydrothermal method with dried pomelo peel and L-tyrosine. The N-CQDs exhibited the blue fluorescence with a quantum yield of 28 %. The sensing principle of N-CQDs was quenched by lemon yellow via static quenching. The potential interfering substances showed no influence on the detection of lemon yellow. The limit of detection was 0.023 mg/L and lower than that of national standard. Furthermore, the synthesized N-CQDs have been successfully applied to the measurement of lemon yellow in real samples. Hence, the N-CQDs would be a promising sensor in food analysis.

Fabrication of abundantly functionalized dendritic biochar composites as adsorbents for the high-efficiency removal of heavy metal ions and dyes

A novel polymer modified biochar composite material (MNBC@p(HGMA-co-PSS-b-AA)) with dendritic structure, abundant functional groups and easy recovery was synthesized, which exhibited excellent removal capacity for Cr(VI), Lemon-Yellow (LY) and Malachite Green (MG). The prepared MNBC@p(HGMA-co-PSS-b-AA) was characterized via thermogravimetric analysis (TGA), scanning electron microscope (SEM) and Fourier transmission infrared spectra (FT-IR), proving to be with abundant functional groups and pore structure. The adsorption capacities for Cr(VI), LY and MG were 421.79, 1169.14 and 1231.53 mg/g, respectively, surpassing the capacities of most previously reported materials in recent years. Additionally, the effects of many factors on adsorption performance were explored. Experimental results indicated that the adsorption of Cr(VI), LY and MG on MNBC@p(HGMA-co-PSS-b-AA) followed pseudo-second-order and Langmuir models. Furthermore, MNBC@p(HGMA-co-PSS-b-AA) still displayed excellent removal capacity for Cr(VI), LY and MG after five reuse cycles. Moreover, different real water samples such as lake water, tap water were used to measure removal efficiency of Cr(VI), LY and MG. The results indicated that removal rates of Cr(VI), LY, and MG were not less than 86.26 %, 98.25 %, and 97.98 %. Meanwhile, MNBC@p(HGMA-co-PSS-b-AA) could maintain removal rate of 85.35 % even after continuously filtering a large number of pollutants solution in adsorption column, revealing its promising applicability for efficient removal of dyes and heavy metal ions. Surprisingly, MNBC@p(HGMA-co-PSS-b-AA) not only quickly adsorbed Cr(VI), but also enabled the concentration of Cr(VI) after adsorption to meet the World Health Organization standard for drinking water. Additionally, FT-IR and X-ray photoelectron spectroscopy (XPS) analysis suggested that adsorption mechanisms for Cr(VI) were hole filling, redox reaction and electrostatic interaction and adsorption mechanisms for LY and MG were hole filling, π–π interaction, π–π electron donor–acceptor (π–π EDA) interaction, electrostatic interaction and hydrogen bond.

A simple and rapid colorimetric detection of methanol, ethanol, and isopropanol and its application toward alcohol-based hand sanitizer quality control

ABSTRACT A practical colorimetric analysis for alcohol determination was devised using a composite of food colorants, specifically a green solution of brilliant blue FCF and tartrazine at a ratio of 1:5 v/v. This colorimetric method was characterized by its simplicity, user-friendliness, environmental compatibility, cost-effectiveness, and suitability for self-measurement through visual examination. The colorimetric procedure entails admixture 1 mL of the alcohol sample with 50 µL of the green test solution and 250 µL of a 30% NaOH solution at ambient temperature. The ensuing color changes were visually assessed within 5 min. Through color sensing, methanol, ethanol, and isopropanol were identified by the manifestation of lemon yellow, orange, and biphasic solutions, respectively. Ethanol was semi-quantified based on color sensing from green to orange, with corresponding concentration ranges. The limit of detection for both methanol and ethanol was determined to be 30% v/v. The developed method demonstrated an accuracy of 93%, with the error range of 1 − 10% v/v and standard deviation of 3.9% v/v, as confirmed by the analysis of 100 commercially available alcohol-based hand sanitizers. This methodology has the potential for further expansion to encompass a wide range of rapid colorimetric analyses of products containing alcohol, including food items, alcohol raw materials, and cosmetics.

Ionic Hyperbranched Poly(amido-amine)-Incorporated Nanofiltration Membranes for High-Efficiency Dye Desalination.

High-efficiency dye desalination is crucial in the textile industry, considering its importance for human health, safe aquatic ecological systems, and resource recovery. In order to solve the problem of effective separation of univalent salt and ionic dye under the condition of high salt, ionic hyperbranched poly(amido-amine) (HBPs) were synthesized based on a simple and scalable one-step polycondensation method and then incorporated into the polyamide (PA) selective layers to construct charged nanochannels through interfacial polymerization (IP) on the surface of a polyvinyl chloride ultrafiltration (PVC-UF) hollow fiber membrane. Both the internal nanopores of HBPs (internal nanochannels) and the interfacial voids between HBPs and the PA matrix (external nanochannels) can be regarded as a fast water molecule transport pathway, while the terminal ionic groups of ionic HBPs endow the nanochannels with charge characteristics for improving ionic dye/salt selectivities. The permeate fluxes and dye/salt selectivities of HBP-TAC/PIP (57.3 L m-2 h-1 and rhodamine B (RB)/NaCl selectivity of 224.0) and HBP-PS/PIP (63.7 L m-2 h-1 and lemon yellow (LY)/NaCl selectivity of 664.0) membranes under 0.4 MPa operation pressure are much higher than PIP-only and HBP-NH2/PIP membranes. At the same time, this project also studied the membrane desalination process in a simulated high-salinity dye/salt mixture system to provide a theoretical basis and technical support for the actual dye desalination process.

Deep learning-based high performance liquid chromatography for food analysis

Abstract This paper presents a study on the determination of synthetic pigments using high performance liquid chromatography (HPLC) method combined. A retention value qualitative approach, combined with an uncertainty assessment algorithm for the determination of pigment content, was used for the simultaneous determination of nine synthetic pigments, namely, lemon yellow, amaranthine red, indigo, carmine, sunset yellow, brilliant blue, seductive red, erythrosine, and seductive red, in foodstuffs by reversed-phase high-performance liquid chromatography (RP-HPLC). The sample pretreatment method was optimized, and the chromatographic conditions were set to investigate the UV determination wavelength, mobile phase, column temperature, and wavelength of synthetic pigments. Under the same mobile phase and column conditions, the results indicated that the components’ retention times did not significantly fluctuate with the change in column temperature. The results showed that the chromatographic response signals of lemon yellow, sunset yellow and seductive red were higher at the UV determination wavelength of 254 nm, so 254 nm was finally determined as the UV detection wavelength in this experiment. Mobile phase A: methanol, B: ammonium acetate (0.02mo/L) using gradient elution, the separation degree R>1.5, and the symmetry and stability of the chromatogram were better. The separation of the components was good, and the peak shape was sharp and symmetric when the column temperature was 35 ℃, so the column temperature was chosen to be 35 ℃, and the establishment of the chromatographic conditions was thus completed.

VALUE ADDITION OF CUT FLOWERS OF GARLAND CHRYSANTHEMUM (GLEBIONIS CORONARIA) BY TINTING WITH ARTIFICIAL FOOD DYES

–Value addition is a method of increasing the economic value of a product. Different value addition techniques are used in horticultural products to increase its economic value, especially in floricultural products. Tinting is one of the value addition techniques used in cut flowers to increase the economic and aesthetic value of simple white and light coloured flowers with food colouring dyes in different novel colour shades. The study “Value addition of cut flowers of garland chrysanthemum (Glebionis coronaria) by tinting with artificial food dyes” was conducted in laboratory of Department of Horticulture, Assam Agricultural University, Jorhat, Assam during February 2022, with seven treatments. The observations like Time taken for tinting, Solution uptake, Colour intensity, Aesthetic appeal and vase life were recorded. Colour intensity of the tinted flower colour was compared using the Royal Horticultural Society (RHS) Colour Chart. Chocolate food colour dye took the earliest time for full tinting (2.43 hr) and Raspberry red took the longest time for full tinting (3.10 hr). The most aesthetically appealing colours were observed on flowers tinted with Lemon yellow, Apple green and Raspberry red. Longest vase life was observed in control (7.6 days) followed by Lemon yellow (4.3 days). Chocolate and Green observed the lowest vase life (2 days). Cut flowers dyed with Lemon yellow recorded the best vase life among the different food dyes.

Морфобиохимические особенности интродуцированных видов Hemerocallis в лесостепи Новосибирской области

In the conditions of the forest-steppe zone of Western Siberia in the Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences, the morphobiochemical features of five species of the genus Hemerocallis were studied: H. lilio-asphodelus – Yellow Daylily, H. minor – L. Malyi, H. middendorffii – L. Middendorf, H. citrina – L. lemon yellow, H. fulva – L. brown-yellow. The paper presents comparative data for 2020-2021. The rhythm of growth and development of spring-early summer flowering species is presented: H. lilio-asphodelus, H. minor, H. middendorffii, H. citrina and summer flowering species H. fulva. Individual morphometric parameters of the height of the generative shoot, the size of the flower, their number in the inflorescence and the number of formed generative shoots over two growing periods are described. Comparative results on the content of ash, ascorbic acid, tannins in leaves, flowers and rhizomes of five species are analyzed. In flowers, the greatest accumulation of ash substances was observed in H. middendorfii (8.3–9.4 %), ascorbic acid in H. citrina (18.1–19.7 mg%). The concentration of ascorbic acid in the leaves of plants of the studied species was high and varied from 15.2 to 17.9 mg%. The ash content in the leaves ranged from 7.1 to 10.4 %, with the highest content in H. lilioasphodelus and H. middendorfii. It was found that the concentration of tannins in the leaves of all species was higher in 2021: 1.1 times in H. lilio-asphodelus; 1.3 times in H. fulva; 1.5 times in H. citrine; 2.1 times in H. minor. In H. middendorfii this indicator was relatively stable (2.3– 2.4 %).The species specificity of morphobiochemical features of introduced species in the south of the Novosibirsk region with aligned and stable adaptive potential is noted, which makes it possible to use them in the landscaping of this region.

Double-enhanced fluorescence of graphene quantum dots from cane molasses via metal and PEG modification for detecting metal ions and pigments

Lead-doped graphene quantum dots modified with polyethylene glycol (PEG-Pb-GQDs) were one-step synthesized using biomass cane molasses as a green carbon source through simple hydrothermal method. The quantum yield (QY) of the PEG-Pb-GQDs can be as high as 30.31%, which is approximately three times that of graphene quantum dots (GQDs) without any modified, indicating that the doping of lead ions and the modification of polyethylene glycol (PEG) can realize the double-sided fluorescence enhancement effect. The as-prepared PEG-Pb-GQDs also exhibit stronger fluorescence, better stability and dispersion compared with lead doped graphene quantum dots (Pb-GQDs). The quasi-spherical PEG-Pb-GQDs were characterized by Fourier transforms infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) to prove the success of lead ions (Pb2+) doping and PEG passivation modification. Multiple metal ions including Fe3+, Cu2+, Ag+, Co2+, Ni2+, Pb2+ and Mn2+ and benzene sulfonic acid pigments including lemon yellow, quinoline yellow and sunset yellow can be detected by PEG-Pb-GQDs. Among the seven responsive metal ions, Fe3+ can be selectively detected under the condition of EDTA and thiourea as masking agent with a limit of detection (LOD) of 0.29 μM for PEG-Pb-GQDs. Correspondingly, Cu2+ and Ag + can also be selectively detected by PEG-Pb-GQDs under appropriate masking agents. The benzene sulfonic acid pigments including lemon yellow, quinoline yellow and sunset yellow can also be selectively detected and the LOD were 0.067, 0.073 and 0.097 μM, respectively. The quenching mechanisms were dynamic quenching for Fe3+, static quenching for Cu2+ and Ag+ and static quenching and fluorescence resonance energy transfer (FRET) for pigments.

Water Safety for Human Health: Detection of Pollutants by Blue-Emission Carbon Quantum Dots via Three Modes in Different Polluted Water Bodies

Water quality directly affects human health. It is very important to design a probe that can detect the pollutants in water. In this study, we synthesized one kind of carbon dots (CDs), which could emit strong blue fluorescence. The blue fluorescence could be quenched by 2,4,6-trinitrophenol (TNP) ascribed to the energy transfer (ET), could be quenched by lemon yellow (LY) ascribed to inner filter effect (IFE), and could be quenched by HClO ascribed to surface passivation (SP). TNP, LY, and HClO are common contaminants in water. By our experiment, it was proved that the synthesized CDs are a safe and effective fluorescent material and could be used to detect the pollutants (TNP, LY, and HClO) in the actual water sample.

One Step Synthesis of Fluorescent Carbon Dots and its Potential Application in pH Detection, Food Additives and Free Radical Scavenging

Lemon yellow is a kind of common food additive. Excessive use of food additives and metabolized free radicals in blood may bring potential harm to human health. In this study, we synthesized a kind of green luminescent fluorescent carbon dots by one-step method, which can effectively detect lemon yellow and this kind of material is sensitive to pH. More importantly, this material can effectively remove superoxide anion and hydroxyl radical. The synthesis method is simple and some unique functions will make this material have greater potential applications.

Constructing carbon microspheres/MnFe2O4/g-C3N4 composite photocatalysts for enhanced photocatalytic activity under visible light irradiation

In this study, ternary photocatalysts (Mn@PC/g-C3N4) were prepared by carbon microspheres, MnFe2O4, and g-C3N4. The structure, morphology, and optical properties of the as-obtained photocatalysts were characterized systematically. Photodegradation of methyl orange (MO) and lemon yellow (LY) under visible light irradiation were carried out to evaluate the photocatalytic performance of Mn@PC/g-C3N4. The impact of ratio of Mn@PC and Mn@PC/g-C3N4 on the photocatalytic activities were investigated. The 20% Mn@PC/g-C3N4 presents the optimum photodegradation rate, which is 6.2 times higher than that of bulk g-C3N4. The superior photocatalytic performance can be ascribed to the enhanced light responsing capacity and light harvesting ability of Mn@PC/g-C3N4 and effective separation of photo-induced charges.

Facile Synthesis of SnS2 Nanoparticles and Catalytic Reduction of Lemon Yellow

SnS2 nanoparticles are synthesized by hydrothermal method from thioacetamide and stannic chloride, and the as-prepared SnS2 nanoparticles are characterized by X-ray diffractometer, scanning electron microscopy, transmission electron microscope, energy dispersive spectrometer and AC impedance spectrum technology. Electrochemical reduction of lemon yellow at nano SnS2-modied glassy carbon electrode is investigated, and the results indicating that the SnS2 nanoparticles have a certain catalytic effect on lemon yellow, and the reduction mechanism and detection of lemon yellow are also discussed.

Novel Preparation of Bi/BiVO4 Catalyst Supported by Alkali-Modified Diatomite and its Visible Light-Driven Degradation Performance

The manufacture of diatomite-supported composite catalyst with enhanced photocatalytic activity is of great interest for wastewater treatment. In this study, the pretreated diatomite (PD) with 5[Formula: see text]wt.% NaOH solution possessed better pore structure and large specific surface area. A facile hydrothermal-photoreduction method was adopted to prepare Bi/BiVO4/PD composite. The chemical composition, microstructure morphology and pore structure of samples were investigated by means of XRF, XRD, SEM, TEM, EDS, XPS and BET methods. The results showed that the metallic Bi was uniformly deposited on the BiVO4. After loaded on PD, both surface area and total pore volume had a significant increase. In addition, UV-vis diffuse reflectance spectra presented that the absorption capacity of Bi/BiVO4/PD-25% composite in the visible light range was remarkably high due to the surface plasmon resonance (SPR) caused by metallic Bi. From photoluminescence (PL) spectra and transient photocurrents, the heterojunction formed between Bi/BiVO4 and PD helped promoting the separation and migration of photo-generated carriers, which in turn led to higher photocatalytic activity. Compared with Bi/BiVO4, Bi/BiVO4/PD loaded with 25[Formula: see text]wt.% PD showed highest decolorization rate for rhodamine B (RhB), malachite green (MG), methylene blue (MB), methyl orange (MO) and lemon yellow (LY) under visible light irradiation. According to trapping experiments on free radicals, the active species that played a decisive role in RhB degradation were h[Formula: see text] and [Formula: see text]. Findings from this study suggest that Bi/BiVO4/PD-25% composite holds great promise for dye degradation and wastewater treatment.

Preparation of magnetic β-cyclodextrin ionic liquid composite material with different ionic liquid functional group substitution contents and evaluation of adsorption performance for anionic dyes

In this study, we successfully prepared two magnetic graphene oxide composites, specifically (mGO@ILs(1)-βCD and mGO@ILs(2)-βCD), with different ionic liquid functional group substitution contents on the β-cyclodextrin (β-CD). Structural characterization of the composite material was performed using Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, specific surface area and pore volume measurements. Comparison of the adsorption performance of the two materials for anionic dyes (lemon yellow (LY), sunset yellow (SY), and ponceau 4R (P4R)) in simulated wastewater. Effect of initial pH value, contact time were studied and discussed in terms of affinity and adsorption efficiency. The adsorption of the anionic azo dye by two adsorbent followed Langmuir adsorption isotherm models and pseudo-second-order kinetics. Noticeably, the maximum adsorption capacity based on the Langmuir model showed that mGO@ILs(2)-βCD was better than mGO@ILs(1)-βCD. Additionally, the adsorbent maintains excellent adsorption capacity after five cycles of adsorption-desorption and has remarkable selective separability. The results showed that the high-density substitution content of the ionic liquid functional groups on β-cyclodextrin in mGO@ILs(2)-βCD is helpful to improve the adsorption capacity and efficiency.

The flotation separation of pyrite from serpentine using lemon yellow as selective depressant

To limit the adverse effect of serpentine on the flotation of pyrite, lemon yellow (LY) was used as a potential depressant for serpentine, and the depression effects and mechanisms were systematically investigated in this paper. Micro-flotation results revealed that the addition of LY could efficiently limit the detrimental effect of serpentine on pyrite flotation with a maximum increase of pyrite recovery from 14% to 96% at pH 9.0. X-ray photoelectron spectroscopy analysis indicated that LY adsorbed on serpentine surface through physical interaction, and electrostatic interaction was considered as the main driving force. Zeta potential results demonstrated that the serpentine surface charge changed from positive to negative after interacting with LY. Thus, the electrostatic attraction between pyrite and serpentine was converted to electrostatic repulsion. Adsorption measurements showed that the adsorption density of potassium butyl xanthate (PBX) on pyrite surface regained after the addition of LY in the presence of serpentine, and thus the pyrite floatability was restored.

Preparation of Ultrafine Spherical Pr-ZrSiO4 Pigment by Sol-Gel-Microemulsion Method

To obtain the ultrafine pigment for ink-jet printing, ultrafine spherical Pr-ZrSiO4 pigment was prepared by sol-gel-microemulsion method (S-G-M). In the emulsion, ZrO2 and SiO2 sols are used as water phase, cyclohexane serves as oil phase, Triton X-100 and 1-hexanol are chosen as surfactant and co-surfactant, respectively. The results show that without the introduction of demulsifier, the sol/oil microemulsion system is demulsified automatically due to the transformation of liquid/liquid to solid/liquid interface following the transformation from sol to gel. The obtained Pr-ZrSiO4 pigment owns uniform spherical particles with the average particle size of about 0.785 μm, which is suitable for the ink-jet printing. The CIE coordination of the pigment is L* = 87.63, a* = −3.82, b* = 65.68, which shows bright lemon yellow. Hence, the ultrafine pigment in this work has the good application prospects.

Adsorption behavior of modified Iron stick yam skin with Polyethyleneimine as a potential biosorbent for the removal of anionic dyes in single and ternary systems at low temperature

The skin of Iron stick yam (ISY) was modified with Polyethyleneimine (ISY@PEI) and evaluated for use as a potential biosorbent to remove the anionic dyes Sunset yellow (SY), Lemon yellow (LY), and Carmine (CM) from wastewater under low temperature conditions (5–15°C) in single and ternary dye systems. Both in the single and ternary systems, experimental data showed that adsorption capacity reached the highest value at 5°C, and adsorption capacity decreased when the temperature increased (10–50°C). The equilibrium data fitted very well to the Langmuir model and the extended Langmuir isotherm, for the single and ternary systems, respectively. The maximum adsorption capability was 138.92, 476.31, and 500.13mg/g for LY, SY, and CM, respectively, in a single system and 36.63, 303.31, and 294.12mg/g for LY, SY, and CM, respectively, in a ternary system. The adsorption followed pseudo-second-order kinetics. The thermodynamic parameters indicated that it was a spontaneous and exothermic process.

<i>Brachystelma seshachalamense</i> (Apocynaceae), a new species from Andhra Pradesh, India

Brachystelma seshachalamense, a new species belonging to the family Apocynaceae, is described from the Seshachalam hills of Kadapa District of Andhra Pradesh, India. The new species is closely allied to Brachystelma beddomei Hook. f., but differs in usually solitary flowers, corolla tube large with a ring of hairs around the corona, corolla lobes spreading with white hairy along the margins and pubescent inside, coronal cup lemon yellow, interstaminal corona shallowly lobed with hairs.Bangladesh J. Plant Taxon. 23(1): 53-57, 2016 (June)

Studies on vase life of tinted spikes of gladiolus cultivar white prosperity

An investigation was undertaken to study the vase life of tinted spikes of gladiolus cultivar. White prosperity harvested at different stages. The experiment comprised of two factors of which the first one was spikes treated with eight food dyes with 5% concentration and time of immersion for two hours and the second one was various stages of harvest. The results revealed that spikes harvested at stage 1(1-2 basal florets show colour) had a higher vase life of 8.16 days, maximum time of 8.56 days to fully loose colour after tinting, lowest mean transpirational loss of 29.17 g. spike-1, highest mean diameter of florets ( 9.21 cm), least decrease of 4.52 g/100g mean percentage of lipids and least decrease of 12.59 g/100g mean percentage of proteins. Benefit cost ratio of tinting the spikes with Lemon yellow, Violet and Orange red was 1.34 while with Kesar yellow, Kalakatta, Blue and Apple green was 1.29. Thus it can be concluded that for tinting the spikes of gladiolus cv. White Prosperity, with greater vase life harvesting the spikes at stage 1(1-2 basal florets show colour) was found to be optimum.