Triphenylmethane Dyes Crystal Violet Research Articles

Gamma‐sterilized cow‐dung for confiscation of triphenylmethane dyes from water bodies

AbstractThe purpose of this work was to adsorb the triphenylmethane dyes crystal violet (CV), brilliant green (BG), and malachite green (MG) from an aqueous solution using cowdung (CD) that has been gamma‐sterilized. FTIR, SEM, EDX, and TGA‐DTA advanced techniques were used to characterize CD. The material had a pHPZC of 6, and it was shown that the maximal monolayer adsorption capacities for CV (at pH 4.83), BG (at pH 4.53), and MG (at pH 3.75) were, respectively, 179.39, 172.28, and 111.62 mg g−1. The equilibrium results were completely described by the pseudo‐second order model and Langmuir isotherm. Using the van't Hoff and Arrhenius equations, thermodynamic parameters like ΔG, ΔS, and ΔH were computed. The exothermic nature of the process change is indicated by the fact that the adsorption of CV and BG increased with lowering temperature whereas the adsorption of MG increased with increasing temperature, as the process was endothermic. Curiously, the values of the adsorption capacity acquired using the column adsorption approach is very similar to those obtained using batch adsorption trials illustrating the CD's capacity for dyes adsorption.

DNA major versus minor groove occupancy of monomeric and dimeric crystal violet derivatives. Toward structural correlations

Six monomeric (1a-1f) and five dimeric (2a-2e) derivatives of the triphenylmethane dye crystal violet (CV) have been prepared. Evaluation of the binding of these compounds to CT DNA by competitive fluorescent intercalator displacement (FID) assays, viscosity experiments, and UV and CD spectroscopy suggest that monomeric derivative 1a and dimeric derivative 2d likely associate with the major groove of DNA, while dimeric derivatives 2a and 2e likely associate with the minor groove of DNA. Additional evidence for the groove occupancy assignments of these derivatives was obtained from ITC experiments and from differential inhibition of DNA cleavage by the major groove binding restriction enzyme BamHI, as revealed by agarose gel electrophoresis. The data indicate that major groove ligands may be optimally constructed from dye units containing a sterically bulky 3,5-dimethyl-N,N-dimethylaniline group; furthermore, the groove-selectivity of olefin-tethered dimer 2d suggests that stereoelectronic interactions (n → π*) between the ligand and DNA are also an important design consideration in the crafting of major-groove binding ligands.

Biosorption of Triphenyl Methane Dyes (Malachite Green and Crystal Violet) from Aqueous Media by Alfa (Stipa tenacissima L.) Leaf Powder.

This study includes the characterization and exploitation of an abundant agricultural waste in Algeria, Alfa (Stipa tenacissima L.) leaf powder (ALP) as a biosorbent for the removal of hazardous triphenylmethane dyes, malachite green (basic green 4) and crystal violet (basic violet 3), from aqueous media under various operating conditions in batch mode. The effect of experimental parameters such as initial dye concentration (10-40 mg/L), contact time (0-300 min), biosorbent dose (2.5-5.5 g/L), initial pH (2-8), temperature (298-328 K), and ionic strength on dye sorption was investigated. The results of both dyes show that the increase in initial concentration, contact time, temperature, and initial pH of solution leads to an increase in biosorbed quantity, unlike the effect of ionic strength. The biosorption kinetics for triphenylmethane dyes on ALP was analyzed by pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models proposed by the Weber-Morris equation. Equilibrium sorption data were analyzed by six isotherms, namely the Langmuir, Freundlich, Harkins-Jura, Flory-Huggins, Elovich, and Kiselev isotherms. The thermodynamic parameters were evaluated for both dyes. The thermodynamic results suggest that both dyes' biosorption is a typical physical process, spontaneous and endothermic in nature.

Studies on degradation of triphenylmethane dye crystal violet by electro‐flotation device

AbstractElectrolysis technology is very effective in removing organic pollutants including dye wastewater and takes into account environmental friendliness. This paper deals with the electrochemical degradation of triphenylmethane dye crystal violet (DCV) from the aqueous solution using 304 stainless steel electrodes. The electrolytic cell device with a flotation column structure was set up and the electrolytic degradation process was studied. It could be found that the DCV removal efficiency and reaction rate constants were fitting the first‐order kinetic model. The process performance was analyzed in terms of degradation efficiency and energy consumption. Almost complete degradation (>98%) of 100 mg/L DCV was achieved after the 40 min reaction under the conditions of 300 mg/L NaCl dosage, nature pH (5–7), and 10 V applied voltage. Finally, the behaviours of degradation were studied. In the process of electrochemical degradation, the synergistic effects of electrode electrolysis, including indirect oxidation of electrolyte, hydroxyl radical, flocculation, and air flotation, removed the dye pollutants from the wastewater. The present study has proved the effectiveness and cleanness of electrochemical treatment for the triphenylmethane dye solution.

Occurrence of Textile Dyes and Metals in Tunisian Textile Dyeing Effluent: Effects on Oxidative Stress Status and Histological Changes in Balb/c Mice.

Although it is known that textile wastewater contains highly toxic contaminants whose effects in humans represent public health problems in several countries, studies involving mammal species are scarce. This study was aimed to evaluate the toxicity profile of 90-days oral administration of textile dyeing effluent (TDE) on oxidative stress status and histological changes of male mice. The TDE was collected from the textile plant of Monastir, Tunisia and evaluated for the metals, aromatic amines, and textile dyes using analytical approaches. Metal analysis by ICP-MS showed that the tested TDE exhibited very high levels of Cr, As, and Sr, which exceeded the wastewater emission limits prescribed by WHO and Tunisian authority. The screening of TDE through UPLC-MS/MS confirmed the presence of two textile dyes: a triphenylmethane dye (Crystal violet) and a disperse azo dye (Disperse yellow 3). Exposure to TDE significantly altered the malondialdehyde (MDA), Conjugated dienes (CDs), Sulfhydryl proteins (SHP) and catalase levels in the hepatic and renal tissues. Furthermore, histopathology observation showed that hepatocellular and renal lesions were induced by TDE exposure. The present study concluded that TDE may involve induction of oxidative stress which ensues in pathological lesions in several vital organs suggesting its high toxicity. Metals and textile dyes may be associated with the observed toxicological effects of the TDE. These pollutants, which may have seeped into surrounding rivers in Monastir city, can cause severe health malaise in wildlife and humans.

Preparation of MgTi2O5 nanoparticles for sonophotocatalytic degradation of triphenylmethane dyes

MgTi2O5 (magnesium dititanate) nanoparticles were prepared by a simple hydrothermal assisted post-annealing method and characterized with various analytical techniques. The catalytic properties (sonocatalytic, photocatalytic and sonophotocatalytic activity) were evaluated using the degradation of triphenylmethane dyes (crystal violet, basic fuchsin, and acid fuchsin). The sonophotocatalytic activity of MgTi2O5 nanoparticles towards crystal violet was found to be ~2.9 times higher than the photocatalytic activity and ~20 times higher than that of the sonocatalytic processes. In addition, the sonophotocatalytic efficiency of MgTi2O5 nanoparticles was found to be remarkable for the degradation of basic fuchsin (cationic dye) and acid fuchsin (anionic dye). The mechanism of these catalytic activities has been discussed in detail.

Oxidation characteristics and degradation potential of a dye-decolorizing peroxidase from Bacillus amyloliquefaciens for crystal violet dye

In the current work, studies were conducted for understanding oxidation characteristics and biodegradation potential of a dye-decolorizing peroxidases from Bacillus amyloliquefaciens (BaDyP) for triphenylmethane dye crystal violet (CV). Recombinant BaDyP from Bacillus amyloliquefaciens MN-13 exhibits a broad substrates profile. It can oxidize ABTS, veratryl alcohol, Mn2+, azo dye reactive black 5, anthraquinone dye reactive blue 19, but cannot oxidize guaiacol. The maximum BaDyP activity against ABTS was obtained at 30 ℃ and pH 4.0. When CV was treated by BaDyP for 72 h, the degradation percentage of 63.0 % was observed. UV–vis spectra and HPLC/MS analysis indicated that CV degradation occurred via N-demethylation and cleavage of conjugated chromophore structure. The identified degradation products included stepwise N-demethylated intermediates during the N-demethylation of CV and, 4-(N-methylamino)-4′-(N’-methylamino) benzophenone and 4-(N-methylamino)-4′-amino benzophenone after cleavage of conjugated chromophore structure. Based on these data, a hypothetic mechanism of CV degradation mediated by BaDyP was proposed in this study. Finally, it is worth to be noted that BaDyP possessed high decolorization efficiency (72.3 % removal ADMI) for actual dye effluent. These results demonstrated that BaDyP might be used as an efficient biocatalyst for the enzymatic pretreatment of dyes in wastewater.

Validation of a method for the determination of triphenylmethane dyes in trout and shrimp with superior extraction efficiency

ABSTRACTThe described methods are able to analyse the triphenylmethane dyes malachite green (MG), crystal violet (CV) and brilliant green (BG) as well as their leuco metabolites leuco malachite green (LMG), leuco crystal violet (LCV) and leuco brilliant green (LBG) on the basis of a simple and fast extraction. The validation of the methods in two studies without and with a heated ultrasonic treatment during the extraction of fortified trout and shrimp samples was successfully performed applying an in-house validation concept. The evaluation of the relevant validation parameters, e.g. the decision limit CCα, the detection capability CCβ, the repeatability, the within-laboratory reproducibility and the recovery for both extraction versions, showed results which fulfil the requirements of Commission Decision 2002/657/EC. The investigation of incurred material of trout containing the above compounds with an additional heated ultrasonic treatment during extraction leads to higher findings of MG and BG. This effect was also confirmed by other laboratories in the framework of a proficiency test. For CV and all three leuco metabolites no increase in the detected amounts could be observed after a heated ultrasonic treatment of the incurred trout material.

Monte Carlo simulation of electric conductivity for pure and doping fullerene (C60)

In this paper, we have used Monte Carlo (MC) method to simulate and study the temperature and doping effects on the electric conductivity of fullerene (C60). The results show that the band gap has reduced by the doping and the charge carrier transport is facilitated from valence band to conduction band by the temperature where is touched a 300 K. In this case, the conductivity reached a value of 4×10−7Scm−1. The electric conductivity of C60 can increase by the triphenylmethane dye crystal violet (CV) alkali metal to reach 4×10−3Scm−1 at 303 K. Our results of MC simulation have a good agreement with those extracted from literature [10,33].

Biodegradation of triphenylmethane dye crystal violet by Cedecea davisae.

The present study focuses on the biodegradation of triphenylmethane dye crystal violet (CV) by Cedecea davisae. The degradation of CV was evaluated via ultraviolet absorbance at 254 nm (UV254) and chemical oxygen demand (COD) removal, and the kinetics was used to evaluate the degradation efficiency. Intermediate products were analyzed via UV-vis spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), and high-performance liquid chromatography (HPLC). Results showed that C. davisae was able to decolorize the CV, and the maximum decolorization ratio reached 97%. COD reduction was observed after decolorization, with average removal rates of >90% after 48 h. Moreover, 50% of UV254 can be removed after 14 h. The removal efficiency of CV by C. davisae followed first- and second-order reaction kinetics at temperature ranged from 20 °C to 40 °C and pH 4.0 to 6.0, respectively. By using UV, the peak representing the CV disappeared 14 h after CV decolorization, and the degradation of aromatic and naphthalene rings was attributed to the formation of a new metabolite. The FTIR spectra of metabolites showed that a new functional group of OH, CH, CH2, CH3, NH, CN, CN, or CO was produced. The chromatograms of HPLC recorded at 589 nm at retention time decreased and were not detected following incubation for 8 h by C. davisae.

Synthesis and DNA binding profile of monomeric, dimeric, and trimeric derivatives of crystal violet

Monomeric, dimeric, and trimeric derivatives of the triphenylmethane dye crystal violet (1a–1f) have been synthesized for the purpose of evaluating their affinity and sequence selectivity for duplex DNA. Competitive ethidum displacement assays indicate that 1a–1f have apparent association constants for CT DNA in the range of 1.80–16.2 × 107 M−1 and binding site sizes of 10–14 bp. Viscosity experiments performed on ligand 1f confirmed that these dyes associate with duplex DNA by a non-intercalative mode of binding. Circular dichroism and competition binding studies of the tightest binding ligand 1e with known major and minor groove binding molecules suggest that these dye derivatives likely occupy the major groove of DNA. Data from the binding of 1e to polynucleotides indicate close to an order of magnitude preference for associating with AT rich homopolymers over GC rich homopolymers, suggesting a shape-selective match of the sterically bulky ligand with DNA containing a wider major groove.

Influence of Dyes on Metal Removal: a Study Using Live and Dead Cells of Penicillium simplicissimum in Single-Metal and Dye-Metal Mixtures

The metal removal efficiency of live and dead fungal cells of Penicillium simplicissimum (isolate 10, KP713758) was tested against 100 ppm toxic metals Cd, Cu, Pb, Zn and trivalent Cr in single-metal solutions and in mixtures with 50 ppm triphenylmethane (TPM) dyes (Cotton Blue, Crystal Violet, Methyl Violet, and Malachite Green). Results revealed that live cells were more effective at removing metals from single (10.8–70.0%) and dye-metal mixtures (5.3–62.2%) than dead cells (5.1–27.4%). The dyes in dye-metal mixtures influenced metal uptake capacity. All four dyes inhibited the uptake of Cd (0.9–7.1%), Zn (5.3–7.7%), Cu (5.0–25.8%) and Cr (47.3–60.7%) by live cells. The exception was the enhance removal of Pb by live cells (48.6 to 56.3–62.2%) in the presence of dye (MG or CB). Pb uptake was not affected by MV (51.8%), but was inhibited by CV (31.9%). For dead cells, uptake of metals (Cd, Cr and Zn) in single (3.2–27.4%) and dye-metal solutions (0.7–27.4%) was similar, whilst removal of Cu (6.4–13.5%) and Pb (33.6–44.0%) was inhibited by all four dyes. P. simplicissimum is concluded to have potential to remove toxic metals even in the presence of TPM dyes, with preferred use of live cells than dead cells.

Partial removal and detoxification of Malachite Green and Crystal Violet from laboratory artificially contaminated water by Pleurotus ostreatus

<p>The triphenylmethane dyes Malachite Green (MG) and Crystal Violet (CV) are cationic dyes and mix with domestic wastewater when dumped; increasing, among others, the chemical and biological demand of oxygen and can cause acute toxicity at different trophic levels. Promoting the removal (decolorization) of MG and CV, and laccase activity (54.8 ± 8.9 and 30.6 ± 2.9 UL-1 respectively) by using <em>P. ostreatus</em> viable biomass needed parameters such as pH (4.5 and 6.0), temperature (25 to 30 °C), stirring speed (120 rpm), percentage of inoculum (2% v/v), and dye concentration (20 and 10 mg L-1). In adsorption studies, it was showed that an acidic pH favors the adsorption of both dyes and the model of pseudo-second order describes best the phenomenon of adsorption. Finally, the germination index (GI), using <em>Lactuca sativa</em> seeds for the initial dyes solutions, was <50%; demonstrating its high phytotoxic effect. When dye solutions were treated with viable biomass, the GI increased, leaving open the possibility to performing future research to determine if the aqueous solutions, post-treated with <em>P. ostreatus</em>, could be used in treatments that generate less toxic water which could be used in processes that do not require potable water.</p>

Biological removal of triphenylmethane dyes from aqueous solution by Lemna minor.

The aim of this study is to investigate and develop a phytoremediation method for the removal of two triphenylmethane dyes (crystal violet and malachite green) using an aquatic plant, Lemna minor. The effects of operational parameters such as aquatic plant quantity, initial dye concentration, initial pH of the solutions and temperature of the medium were studied in order to determine the optimum phytoremediation conditions. The plant's photosynthetic pigments were determined quantitatively in order to detect the plant's response to abiotic stress. During the phytoremediation experiments the parallel sub-processes (phytosorption, phytoextraction, phytodegradation) were observed and analysed. The mechanisms of phytoremediation were studied using Fourier transformation infrared spectroscopy, ultraviolet-visible spectroscopy, thin layer chromatography and Energy-dispersive X-ray spectroscopy. Results show that the plant tolerated high concentrations (300 mg/L) of dyes, and was able to remove from the environment and accumulate in its cells the dyes up to a significant percentage (crystal violet was removed by about 80% and malachite green by 90%).

Preparation and characterisation of silver‐ or copper‐doped TiO2 catalysts and their catalytic activity in dye degradation

In this study, silver‐ or copper‐doped TiO2–Ce‐, TiO2–La‐, and commercial TiO2 (P25)‐supported catalysts were prepared. The catalysts and supports were characterised by powder X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption studies. UV‐light‐assisted heterogeneous Fenton‐like oxidation of two different‐structure dyes (anionic azo dye Orange II, CI Acid Orange 7 and cationic triphenylmethane dye Crystal Violet, CI Basic Violet 3) was investigated over the catalysts. Higher catalytic activity was observed in the oxidation of Orange II than in the oxidation of Crystal Violet. For both dyes, the TiO2–Ce and TiO2–La‐supported catalysts, which were in the form of anatase only, gave higher photocatalytic activity than the P25‐supported catalysts, which were in the form of anatase and rutile. Complete colour removal was observed during oxidation of Orange II over Cu/TiO2–Ce and Cu/TiO2–La catalysts, whereas the highest degree of decolorisation, 89.3%, was achieved by oxidation of Crystal Violet over Ag/TiO2–Ce. The pH of the solution affected the surface state of the TiO2, thus affecting the photocatalytic degradation of the dyes. The surface area of the catalysts is also a key parameter that influences their photocatalytic activity. It was observed that catalysts having higher surface areas brought about greater dye degradation.

Determination of Triphenylmethane Dyes and Their Metabolites in Salmon, Catfish, and Shrimp by LC-MS/MS Using AOAC First Action Method 2012.25: Collaborative Study.

A collaborative study was conducted to evaluate the AOAC First Action 2012.25 LC-MS/MS analytical method for the determination of residues of three triphenylmethane dyes (malachite green, crystal violet, and brilliant green) and their metabolites (leucomalachite green and leucocrystal violet) in seafood. Fourteen laboratories from the United States, Canada, and the European Union member states participated in the study including national and state regulatory laboratories, university and national research laboratories, and private analytical testing laboratories. A variety of LC-MS/MS instruments were used for the analysis. Each participating laboratory received blinded test samples in duplicate of salmon, catfish, and shrimp consisting of negative control matrix; matrix fortified with residues at 0.42, 0.90, and 1.75 μg/kg; and samples of incurred matrix. The analytical results from each participating laboratory were evaluated for both quantitative residue determination and qualitative identification of targeted analytes. Results from statistical analysis showed that this method provided excellent trueness (generally ≥90% recovery) and precision (RSDr generally ≤10%, HorRat<1). The Study Directors recommend Method 2012.25 for Final Action status.

Expansion of the Scope of AOAC First Action Method 2012.25--Single-Laboratory Validation of Triphenylmethane Dye and Leuco Metabolite Analysis in Shrimp, Tilapia, Catfish, and Salmon by LC-MS/MS.

Prior to conducting a collaborative study of AOAC First Action 2012.25 LC-MS/MS analytical method for the determination of residues of three triphenylmethane dyes (malachite green, crystal violet, and brilliant green) and their metabolites (leucomalachite green and leucocrystal violet) in seafood, a single-laboratory validation of method 2012.25 was performed to expand the scope of the method to other seafood matrixes including salmon, catfish, tilapia, and shrimp. The validation included the analysis of fortified and incurred residues over multiple weeks to assess analyte stability in matrix at -80°C, a comparison of calibration methods over the range 0.25 to 4 μg/kg, study of matrix effects for analyte quantification, and qualitative identification of targeted analytes. Method accuracy ranged from 88 to 112% with 13% RSD or less for samples fortified at 0.5, 1.0, and 2.0 μg/kg. Analyte identification and determination limits were determined by procedures recommended both by the U. S. Food and Drug Administration and the European Commission. Method detection limits and decision limits ranged from 0.05 to 0.24 μg/kg and 0.08 to 0.54 μg/kg, respectively. AOAC First Action Method 2012.25 with an extracted matrix calibration curve and internal standard correction is suitable for the determination of triphenylmethane dyes and leuco metabolites in salmon, catfish, tilapia, and shrimp by LC-MS/MS at a residue determination level of 0.5 μg/kg or below.

Genetic characterization of plasmid-associated triphenylmethane reductase in Listeria monocytogenes.

The enzyme triphenylmethane reductase (TMR) reduces toxic triphenylmethane dyes into colorless, nontoxic derivatives, and TMR-producing microorganisms have been proposed as bioremediation tools. Analysis of the genome of Listeria monocytogenes H7858 (1998-1999 hot dog outbreak) revealed that the plasmid (pLM80) of this strain harboring a gene cassette (bcrABC) conferring resistance to benzalkonium chloride (BC) and other quaternary ammonium disinfectants also harbored a gene (tmr) highly homologous to TMR-encoding genes from diverse Gram-negative bacteria. The pLM80-associated tmr was located two genes downstream of bcrABC as part of a putative IS1216 composite transposon. To confirm the role of tmr in triphenylmethane dye detoxification, we introduced various tmr-harboring fragments of pLM80 in a pLM80-cured derivative of strain H7550, from the same outbreak as H7858, and assessed the resistance of the constructs to the triphenylmethane dyes crystal violet (CV) and malachite green. Transcriptional and subcloning data suggest that the regulation of TMR is complex. Constructs harboring fragments spanning bcrABC and tmr were CV resistant, and in such constructs tmr transcription was induced by sublethal levels of either BC or CV. However, constructs harboring only tmr and its upstream intergenic region could also confer resistance to CV, albeit at lower levels. Screening a panel of BC-resistant L. monocytogenes strains revealed that all those harboring bcrABC and adjacent pLM80 sequences, including tmr, were resistant to CV and decolorized this dye. The findings suggest a potential role of TMR as a previously unknown adaptive attribute for environmental persistence of L. monocytogenes.

Rapid decolorization of anthraquinone and triphenylmethane dye using chloroperoxidase: Catalytic mechanism, analysis of products and degradation route

A rapid and efficient enzymatic decolorization of anthraquinone (Alizarin Red) and triphenylmethane dyes (Crystal Violet) by a heme peroxidase, chloroperoxidase (CPO), was presented in this work. The decolorization efficiency of Alizarin Red reached 98.23%, and that of Crystal Violet was 97.68% both within 7 min at mild condition with an enzyme concentration below ppm level. A characteristic mechanism was involved in this enzymatic oxidation, in which some small intermediates with high oxidative activity generated online during enzymatic catalytic cycle. The decolorization was in fact carried out in bulk solution instead of in heme, which can get rid of the restriction for the size of dyes required by the channel access to enzymatic active site. UV–vis and HPLC–MS analysis of products indicated the chromophoric groups were destructed and the dye molecules were broken-down into small pieces, indicating an increase in biodegradability of the dyes. COD and TOC values of dyes solution were all decreased. Meanwhile, the strong toleration of this CPO-catalyzed oxidative decolorization to the typical salt species (NaCl, NaNO3, and Na2SO4) was observed, which showed a potential application of this method in treatment of industrial wastewater.

Fast analysis of malachite green, leucomalachite green, crystal violet and leucocrystal violet in fish tissue based on a modified QuEChERS procedure.

Triphenylmethane dyes malachite green (MG) and crystal violet (CV) have been used as antimicrobial, antiparasitic and antiseptic agents in aquaculture. However, MG and CV, as well as their metabolites leucomalachite green (LMG) and leucocrystal violet (LCV) are potential mutagens and carcinogens. Thus, the efficient determination of dye residues is of great concern. Considering the complexity of the aquatic products, the sample pretreatment is significant for decreasing matrix interference and improving detection sensitivity. In this study, a simple and rapid QuEChERS procedure was developed and combined with HPLC analysis for the simultaneous determination of the four dyes in fish tissue. An XCharge C18 column was applied in HPLC analysis to achieve good peak shape and selectivity. The pretreatment method involved the extraction of dyes from fish tissue and further clean-up with dispersive solid phase extraction (d-SPE) material. The extraction volume, extraction time as well as d-SPE materials were systematically optimized. The results indicated that reversed-phase/strong anion exchange (C18SAX) adsorbent in the d-SPE procedure could effectively improve the recovery compared with conventional C18 or C18 incorporated with primary secondary amine (PSA) material. Under optimized conditions, good linearity was achieved in the concentration range of 0.5-100 mg/L with R2 greater than 0. 998. The recoveries were 73%-91% and the precisions were 0.66%-5.41%. The results demonstrated the feasibility and efficiency of QuEChERS procedure incorporated with HPLC for dye monitoring.