RESUMO
Confirmatory identification of dyes in the physical pieces of evidence, such as hair and fabric, is critically important in forensics. This information can be used to demonstrate the link between a person of interest and a crime scene. High performance liquid chromatography is broadly used for dye analysis. However, this technique is destructive and laborious. This problem can be overcome by near-Infrared excitation Raman spectroscopy (NIeRS), non-invasive and non-destructive technique that can be used to determine chemical structure of highly fluorescent dyes. Analyzed fabric materials often possess body fluid stains, which may obscure the accuracy of NIeRS-based identification of dyes. In this study, we investigate the extent to which fabric contamination with body fluids can alter the accuracy of NIeRS. Our results showed that NIeRS coupled with partial-least squared discriminant analysis (PLS-DA) enabled on average 97.6% accurate identification of dyes on fabric contaminated with dry blood, urine and semen. We also found that NIeRS could be used to identify blood, urine and semen on such fabric with 99.4% accuracy. Furthermore, NIeRS could be used to differentiate between wet and dry blood, as well as reveal the presence of blood on washed fabric. These results indicate that NIeRS coupled with PLS-DA could be used as a robust and reliable analytical approach in forensic analysis of fabric.
Assuntos
Análise Espectral Raman , Têxteis , Análise Espectral Raman/métodos , Têxteis/análise , Humanos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Líquidos Corporais/química , Sêmen/química , Corantes/química , Corantes/análise , Ciências Forenses/métodosRESUMO
Biomaterials like chitosan, hydroxyapatite have been used in biomedical and pharmaceutical field, due to its valuable biochemical and physiological properties. In current work firstly our group has isolated a polysaccharide chitosan along with hydroxyapatite biomaterial from the same source by varying the process condition via greener approach. We have adapted greener approach for the isolation of chitosan within a short period of time and this is the very first report for the isolation of both chitosan and hydroxyapatite simultaneously from the same waste edible garden snail shells. Both these materials were thoroughly characterized by using UV, FT-IR, SEM techniques. Among synthetic colourants, congo red dye is recognized as carcinogens, which are usually used in the textile manufacturing. Interestingly, one of our biomaterial hydroxyapatite has shown good selectivity towards Congo red dye. The sensitivity range was obtained from 10 to 100 µM within the LOD of 101.52 nM. The developed sensor has been tested for various industrial effluents and shown good agreement with our results. Meanwhile these chitosan and hydroxyapatite have also been used as capping agent for the preparation of stable gold nanoparticles.
Assuntos
Quitosana , Vermelho Congo , Durapatita , Quitosana/química , Vermelho Congo/química , Animais , Durapatita/química , Caramujos/química , Exoesqueleto/química , Química Verde/métodos , Corantes/química , Corantes/isolamento & purificação , Corantes/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Nanopartículas Metálicas/química , Ouro/químicaRESUMO
Henna is a plant-based dye obtained from the powdered leaf of the pigmented plant Lawsonia inermis, and has often been used for grey hair dyeing, treatment, and body painting. As a henna product, the leaves of Indigofera tinctoria and Cassia auriculata can be blended to produce different colour variations. Although allergy from henna products attributed to p-phenylenediamine, which is added to enhance the dye, is reported occasionally, raw material plants of henna products could also contribute to the allergy. In this study, we reported that raw material plants of commercial henna products distributed in Japan can be estimated by LC-high resolution MS (LC-HRMS) and multivariate analysis. Principal Component Analysis (PCA) score plot clearly separated 17 samples into three groups [I; henna, II; blended henna primarily comprising Indigofera tinctoria, III; Cassia auriculata]. This grouping was consistent with the ingredient lists of products except that one sample listed as henna was classified as Group III, indicating that its ingredient label may differ from the actual formulation. The ingredients characteristic to Groups I, II, and III by PCA were lawsone (1), indirubin (2), and rutin (3), respectively, which were reported to be contained in each plant as ingredients. Therefore, henna products can be considered to have been manufactured from these plants. This study is the first to estimate raw material plants used in commercial plant-based dye by LC-HRMS and multivariate analysis.
Assuntos
Espectrometria de Massas , Análise Multivariada , Folhas de Planta/química , Lawsonia (Planta)/química , Indigofera/química , Corantes/química , Corantes/análise , Cassia/química , Cromatografia Líquida , Cromatografia Líquida de Alta Pressão , Análise de Componente Principal , Naftoquinonas/química , Naftoquinonas/análise , Estrutura MolecularRESUMO
Excavations in the Eastern Suburb of Bronze Age Aegina Kolonna revealed the destruction deposit of two sequenced Early Mycenaean buildings (phase Late Helladic IIA; 16th century BC). The older building is interpreted as a widely undisturbed production site of purple-dye based on indicative finds such as ceramic sherds containing analyzable quantities of pigment, high amounts of mollusk shells, and a few functional facilities. Chemical analysis by HPLC and malacological determination revealed that the banded dye-murex (Hexaplex trunculus) was used almost exclusively. The presence of crushing tools and a waste disposal pit provide insight into the technical process of dye production. Additionally, skeletal remains of heavily burnt infantile and juvenile piglets, kids, or lambs were found in the purple workshop area. The evidence may be better explained by ritual activities aimed at promoting the highly meaningful event of purple production, rather than by normal food consumption practices.
Assuntos
Arqueologia , Animais , História Antiga , Corantes/história , Corantes/análise , Humanos , Suínos , OvinosRESUMO
Tefillin are Jewish ritual artifacts consisting of leather cases, containing inscribed slips, which are affixed with leather straps to the body of the tefillin practitioner. According to current Jewish ritual law, the tefillin cases and straps are to be colored black. The present study examines seventeen ancient tefillin cases discovered among the Dead Sea Scrolls in caves in the Judean Desert. All seventeen cases display grain surfaces with a very dark, nearly black appearance. We start with a hypothesis that the cases were intentionally colored black in antiquity using either a carbon-based or iron-gall-based paint or dye. The aim of this study is to test this hypothesis by subjecting these tefillin cases to a battery of examinations to assess the presence of carbon and iron used as pigments, and of organic materials which may have been used as binding agents in a paint. The tests deployed are: (1) macroscopic and microscopic analyses; (2) multispectral imaging using infrared wavelengths; (3) Raman spectroscopy; (4) Fourier transform infrared spectroscopy (FTIR); and (5) scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy. The results of these tests found no traces of carbon-based or iron-gall-based pigments, nor of organic compounds which may have served as binders in a paint. These results suggest that our posited hypothesis is unlikely. Instead, results of the SEM examination suggest it more likely that the black color on the surfaces of the tefillin cases is the result of natural degradation of the leather through gelatinization. The Judean Desert tefillin likely represent tefillin practices prior to when the rabbinic prescription on blackening tefillin was widely practiced. Our study suggests that the kind of non-blackened tefillin which the later rabbis rejected in their own times may well have been quite common in earlier times.
Assuntos
Análise Espectral Raman , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , História Antiga , Pintura/análise , Pintura/história , Cavernas , Espectrometria por Raios X , Clima Desértico , Comportamento Ritualístico , Corantes/análise , Corantes/químicaRESUMO
This study aimed to develop an ammonia and pH super-sensitive label by incorporating methyl red and bromothymol blue (MR-BTB, MB) into gellan gum/sodium carboxymethyl cellulose (GG/CMC-Na, GC). Furthermore, E-nose as an auxiliary tool combined with the labels to monitor meat freshness. Results showed that MB had more color change than pure MR or BTB, and the detection limit of ammonia about the MR-BTB (1:2) group was only 2.82 ppm. The addition of MB significantly increased tensile strength, moisture content, and water solubility, but decreased elongation at break and transmittance of the GC label (p < 0.05). The result of FTIR and SEM indicated the formation of hydrogen bonds and well compatibility between MB and GC. Furthermore, the color of the GC-10.0MB label was constantly obviously changing during meat storage, indicating that the GC-10.0MB label had great potential for monitoring the freshness of the lamb meat. A high correlation was found between ΔE of GC-10.0MB label and TVB-N (R2 = 0.9092) and pH (R2 = 0.9114) of meat. Interestingly, the high correlation between ΔE of GC-10.0 MB label and the response value of S2 (R2 = 0.7531), S6 (R2 = 0.9921), and S7 sensor (R2 = 0.8325) of E-nose was also found.
Assuntos
Amônia , Carboximetilcelulose Sódica , Colorimetria , Polissacarídeos Bacterianos , Carboximetilcelulose Sódica/química , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/análise , Concentração de Íons de Hidrogênio , Amônia/análise , Amônia/química , Animais , Colorimetria/métodos , Ovinos , Corantes/química , Corantes/análise , Carne Vermelha/análise , Carne/análise , CorRESUMO
Water pollutants such as heavy metal ions, pesticides, and dyes pose a worldwide issue. Their presence in water resources interferes with the normal growth mechanisms of living beings and causes long or short-term diseases. For this reason, research continuously tends to develop innovative, selective, and efficient processes or technologies to detect and remove pollutants from water. This review provides an up-to-date overview on metal nanoparticles loaded in polymeric matrices, such as hydrogels and membranes, and employed as optical sensors and as removing materials for water pollutants. The synthetic pathways of nanomaterials loading into polymeric matrices have been analyzed, particularly focusing on noble metal nanoparticles, noble metal nanoclusters, and metal oxide nanoparticles. Moreover, the sensing properties of modified matrices towards water pollutants have been discussed in addition to the interaction mechanisms between the sensors and the toxic compounds. The last part of the review has been devoted to illustrating the separation mechanism and removal performance of membranes loaded with nanomaterials in the treatment and purification of water streams from different contaminants (heavy metals, dyes and pesticides).
Assuntos
Corantes , Nanopartículas Metálicas , Metais Pesados , Praguicidas , Polímeros , Poluentes Químicos da Água , Metais Pesados/análise , Metais Pesados/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Praguicidas/análise , Praguicidas/química , Corantes/química , Corantes/análise , Nanopartículas Metálicas/química , Polímeros/química , Purificação da Água/métodos , Nanoestruturas/químicaRESUMO
As emerging organic contaminants, Polyhalogenated carbazoles (PHCZs) have caused wide concerns due to their wide distribution in the environment and dioxin-like toxicity. Nevertheless, research on the distribution and formation mechanisms of PHCZs in polluted environment of printing and dyeing plants is lacking. Here, 11 PHCZs were detected in samples from the Cao'e River, China, a typical river heavily polluted by printing and dyeing. The PHCZs concentrations in the soil, sediment, and water samples were 8.3-134.5 ng/g (median: 26.3 ng/g), 17.7-348.8 ng/g (median: 64.2 ng/g), and 1.2-41.4 µg/L (median: 4.8 µg/L), respectively. 3,6-dichlorocarbazole was the dominant congener, proved by both analysis results and formation mechanisms. PHCZ migration patterns in water-sediment systems indicated that highly halogenated PHCZs tend to be transferred to sediment. Furthermore, PHCZs are persistent, can undergo long-range transport, and pose high risks to aquatic organisms by models. PHCZs released from dye production into environment can be form through halogenation of carbazole or PHCZs formed during the dye synthesis, heating of halogenated indigo dyes, and photolysis of highly halogenated PHCZs. This is the first comprehensive study to reveal the impact of printing and dyeing plant activities on PHCZs in the environment.
Assuntos
Carbazóis , Monitoramento Ambiental , Poluentes Químicos da Água , Carbazóis/química , Carbazóis/análise , Poluentes Químicos da Água/análise , China , Corantes/análise , Corantes/química , Rios/química , Sedimentos Geológicos/química , HalogenaçãoRESUMO
Nowadays, secondary raw materials (SRM) obtained from plant matrices are of great interest for circular economy, suitable for sustainable measures to reduce environmental impact. This work focused on the extraction, characterization and quantification of compounds obtained from leaves and fruits of the Sicilian sumac, Rhus coriaria L. and their application as natural dyes on textile fibres. Extractions were performed with Extractor Naviglio®, maceration and ultrasound assisted methods and food-grade solvents (aqueous and hydroalcoholic) to evaluate the yields for dye compounds. The presence of colouring molecules was evaluated by UV-Vis spectrophotometer, and the extracts selected for colouring were quantified and characterized by LC-MS. The results showed that Extractor Naviglio® achieved the best extraction yield, and the ethanol-water mixture extracts had a higher amount of total phenolic compounds (TPC) and a higher content of total colouring compounds (TCC). These extracts were selected for subsequent applications as dyes for linen, cotton and wool. The chemical profile of selected extracts was rich in compounds such as gallotannin and anthocyanin class. Fibre dyeing was verified by recording CIELAB colouring coordinates. The results suggest that the dyes obtained from R. coriaria can be of great interest for artisanal and industrial processes, in accordance with environmental sustainability.
Assuntos
Corantes , Extratos Vegetais , Rhus , Rhus/química , Corantes/química , Corantes/análise , Extratos Vegetais/química , Folhas de Planta/química , Frutas/química , Fenóis/química , Fenóis/análise , Têxteis/análise , Solventes/químicaRESUMO
The dyeing and adulteration of traditional Chinese medicines (TCMs) are continuously updated. Valuable analytical methods for the daily inspection of illegal colorant additives in TCMs and the preparations are in demand. Two deep eutectic solvent (DES)-based vortex-assisted liquid-liquid microextraction (VA-LLME) and ultrasonic-assisted solid-liquid microextraction (UA-SLME) were developed for the sample pretreatment of ten water-soluble colorants and five water-insoluble colorants, respectively, followed by an HPLC-DAD detection. Fifteen colorants were analyzed at four detection wavelengths within 40 min of gradient elution. The optimal DES of VA-LLME and UA-SLME were screened from 23 homemade DESs. The factors affecting the extraction efficiency of VA-LLME and UA-SLME were optimized systematically. Under the optimal conditions, ten water-soluble colorants analyzed by DES-based VA-LLME-HPLC-DAD showed good linearity (R ≥ 0.9995) within the optimal linear range. The LODs and LOQs were 0.2-1.0 µg g-1 and 0. 5-5.0 µg g-1, respectively. The recoveries of spiked samples were 80.2%-104.7 %, with RSDs ≤ 4.39 %. Five water-insoluble colorants of Sudan IâIV and Sudan 7B analyzed by DES-based UA-SLME-HPLC-DAD showed good linearity (R ≥ 0.9995) within the optimal linear range. The LODs and LOQs were 0.8-8.0 µg g-1 and 4.0-40.0 µg g-1, respectively. The recoveries of spiked samples were 94.2%-103.1 %, with RSDs ≤ 4.81 %. The proposed DES-based VA-LLME-HPLC-DAD was successfully applied to analyze six water-soluble yellow colorants in Cuscutae Semen, salted Cuscutae Semen, and four water-soluble red colorants in Schisandrae Chinensis Fructus. The proposed DES-based UA-SLME-HPLC-DAD was successfully applied to analyze five water-insoluble red colorants in Dieda pills. The study provides analytical method options for routine tests of water-soluble, water-insoluble, or both water-soluble/-insoluble illegal colorant additives in herbal medical materials and preparations by the relevant proposed DES-based sample pretreatment method or a combination of the two proposed DES-based methods.
Assuntos
Corantes , Medicamentos de Ervas Chinesas , Interações Hidrofóbicas e Hidrofílicas , Microextração em Fase Líquida , Cromatografia Líquida de Alta Pressão/métodos , Microextração em Fase Líquida/métodos , Corantes/química , Corantes/análise , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/análise , Medicina Tradicional Chinesa , Solventes/químicaRESUMO
In this work, a multiplexed colorimetric strategy was initiated for simultaneous and fast visualization of dyes using low-cost and easy-to-prepare indicator papers as sorbents. Response surface methodology (RSM) was employed to model statistically and optimize the process variables for dyes extraction and colorimetric assays. Multiplexed colorimetry was realized by virtue of synchronous color alignments from different dimensions of multiple dyes co-stained colorimetric cards under RSM-optimized conditions, and smartphone-based image analysis was subsequently performed from different modes to double-check the credibility of colorimetric assays. As concept-to-proof trials, simultaneous visualization of dyes in both beverages and simulated dye effluents was experimentally proved with results highly matched to HPLC or spiked amounts at RSM-predicted staining time as short as 50 s â¼3 min, giving LODs as low as 0.97 ± 0.22/0.18 ± 0.08 µg/mL (tartrazine/brilliant blue) for multiplexed colorimetry, which much lower than those obtained by single colorimetry. Since this is the first case to propose such a RSM-guided multiplexed colorimetric concept, it will provide a reference for engineering of other all-in-one devices which can realize synchronous visualization applications within limited experimental steps.
Assuntos
Colorimetria , Corantes , Smartphone , Colorimetria/métodos , Corantes/química , Corantes/análise , Contaminação de Alimentos/análise , Tartrazina/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Processamento de Imagem Assistida por Computador/métodos , Benzenossulfonatos/química , Bebidas/análiseRESUMO
Here, we demonstrated the synthesis of a zinc based luminescent MOF, 1 (NDC = 2,6- naphthalenedicarboxylate) for the ratiometric detection of biomarker riboflavin (RBF; vitamin B2) in water dispersed medium. Further, this MOF detected two other antibiotic drug molecules, nitrofurantoin (NFT) and nitrofurazone (NZF). The detection of these analytes is very quick (â¼seconds), and the limit of detection (LOD) for RBF, NZF and NFT are calculated as 16.58 ppm, 47.63 ppb and 56.96 ppb, respectively. The detection of these analytes was also comprehended by solid, solution, cost-effective paper strip method i.e., triphasic identification capabilities. The sensor is reusable without losing its detection efficacy. The sensor further showed the recognition abilities of these antibiotics in real field samples (river water, urine and tablet) and RBF in vitamin B2 pills and food samples (milk and cold drinks). The sensing merit of 1 urged us to fabricate of 1@cotton fabric composite, which exhibited the colorimetric detection of these analytes. In-depth experimental analysis suggested that the occurrence of photo-induced electron transfer (PET), fluorescence resonance energy transfer (FRET), and the inner filter effect (IFE) are the possible sensing mechanisms for the recognition of the antibiotics drug. The FRET mechanism is responsible for the recognition of RBF. The sensing mechanism is further supported by the theoretical analysis and the excited lifetime measurement.
Assuntos
Antibacterianos , Transferência Ressonante de Energia de Fluorescência , Antibacterianos/análise , Nitrofurantoína , Corantes/análise , Água , Vitaminas/análiseRESUMO
Some synthetic dyes are fraudulently added into spices to appeal visually to consumers. Food regulations in several countries, including the United States, Australia, Japan and the European Union, strictly prohibit the use of unauthorised synthetic dyes in food. Nevertheless, illegal practices persist, where spices contaminated with potentially carcinogenic dyes have been documented, posing potential health risks to consumers. In the present study, 14 synthetic dyes were investigated through liquid chromatography/tandem mass spectrometry in 252 commercially available spices in the Singapore market. In 18 out of these (7.1%) at least 1 illegal dye was detected at concentrations ranging from 0.010 to 114 mg/kg. Besides potential health risks, presence of these adulterants also reflects the economic motivations behind their fraudulent use. Findings in the present study further emphasise the need for increased public awareness, stricter enforcement, and continuous monitoring of illegal synthetic dyes in spices to ensure Singapore's food safety.
Assuntos
Contaminação de Alimentos , Especiarias , Espectrometria de Massas em Tandem , Especiarias/análise , Singapura , Contaminação de Alimentos/análise , Humanos , Corantes/análise , Corantes/química , Corantes de Alimentos/análiseRESUMO
In this work, a novel magnetic covalent organic framework (COF (TpPa-NH2) @ Fe3O4) was prepared via two step by simple solvent method for the extraction of anionic azo dye residues in food. The as-prepared COF (TpPa-NH2) @ Fe3O4 nanocomposite was characterised by scanning electron microscope, transmission electron microscope, Fourier transform-infrared spectroscopy, X-ray diffraction and vibrating sample magnetometer. Before high-performance liquid chromatography with ultraviolet detection (HPLC-UV) determination, it was used as magnetic adsorbent for magnetic solid-phase extraction (MSPE) to extract and pre-concentrate three anionic azo dyes in carbonated beverage samples. The several key extraction and desorption parameters affecting the extraction recovery rate were investigated, including extraction time, pH of the solution, amount of material, adsorption time, elution solvent, pH of elution solvent, type of elution solvent, elution volume and elution time. Under optimised conditions, this method has good linearity between 5 and 500 µg L-1 (correlation coefficient > 0.9986). The limit of detection was 2.3-3.4 µg L-1. The recoveries of the samples were between 87.5 and 96.9%, and the relative standard deviation lower than 4.6%. The developed method has broad application prospects for the analysis of anionic azo dyes in carbonated beverages.
Assuntos
Compostos Azo , Bebidas Gaseificadas , Compostos Azo/análise , Compostos Azo/química , Compostos Azo/isolamento & purificação , Bebidas Gaseificadas/análise , Extração em Fase Sólida/métodos , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/síntese química , Corantes/química , Corantes/isolamento & purificação , Corantes/análise , Ânions/química , Ânions/análise , Adsorção , Aminas/química , Aminas/análise , Aminas/isolamento & purificaçãoRESUMO
BACKGROUND: Pigment Red 53 is a dangerous synthetic dye that is often added to cosmetics, even though its use in cosmetic products has been prohibited because of possible impacts on health. Faster and more sensitive detection of Pigment Red 53 is needed for onsite analysis to protect the community from illegal cosmetics that contain the dye. Indicator color charts are a kind of analytical method that can be used to detect Pigment Red 53 in cosmetic products, including lipstick, rouge, and eyeshadow. Such charts are practical, fast, and can be used for onsite analysis. METHODS: In this study, an indicator for Pigment Red 53 detection was obtained through a reagent reaction that caused a specific color change. An indicator color chart was then produced by setting out in paper form the series of colors which resulted from the reaction of specific chemical reagents and Pigment Red 53 solutions at concentrations of 10, 20, 40, 60, 80, and 100 ppm. RESULTS: The testing results showed that the indicator color chart may be used as an initial screening method for the detection of Pigment Red 53 in cosmetic products with a detectable minimum concentration of 10 ppm. Out of nine samples, only one (Eyeshadow 3) tested positive for Pigment Red 53. Further analysis was carried out on the indicator color chart and the results showed good agreement with TLC and UV-Vis spectrophotometry methods. CONCLUSION: The results reported in this paper demonstrate that the indicator color chart is a good prospective method for onsite analysis to detect Pigment Red 53 in cosmetic samples, with a lower detection limit compared to polymer-based indicators.
Assuntos
Corantes , Cosméticos , Cosméticos/química , Cosméticos/análise , Indonésia , Humanos , Corantes/análise , Cor , Colorimetria/métodos , Compostos Azo/análise , Compostos Azo/química , Indicadores e Reagentes/químicaRESUMO
Colorants have been a staple in the cosmetics industry for a considerable time, although certain varieties have been banned owing to health risks. Detecting and confirming these banned colorants simultaneously poses several challenges when employing LC-MS/MS. Molecular networking is a promising analytical technology that can be used to predict the structure of components and the correlation between them using structural and MS/MS spectral similarities. Molecular networking entails assessing the number of fragmented ions and the cosine score (the closer it is to one, the higher the similarity). In this study, we developed and verified a method for the simultaneous quantitative analysis of the 26 banned colorants in cosmetics using LC-MS/MS. Additionally, we propose a novel approach that combines LC-Q-TOF-MS and molecular networking technology to detect banned colorants in cosmetics. For successful molecular networking, a minimum of six fragment ions with cosine scores exceeding 0.5 is required. We developed a screening method for characterizing banned colorants using molecular networking based on LC-TOF-MS results for 26 banned colorants. Furthermore, we demonstrated that our established method can be used for screening by analyzing actual cosmetics (eyebrow tattoo, lipstick tattoo, and hair tint) spiked with three non-targeted banned colorants with similar structures (m/z 267.116, 315.149, and 345.157) in cosmetics. The combination of molecular networking techniques and LC-MS/MS proves highly advantageous for the swift characterization and screening of non-targeted colorants in cosmetics.
Assuntos
Corantes , Cosméticos , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Cosméticos/química , Cosméticos/análise , Cromatografia Líquida/métodos , Corantes/química , Corantes/análiseRESUMO
Infiltration of binary solution of hexane and ethanol into chromatography paper associated with their evaporation was found to generate unexpected initial rapid advancement of wicking front followed by its receding and readvancing in our previous research. In the present study, paper chromatography development of hydrophobic dye, Sudan III, and hydrophilic dye, Acid Blue 9, was carried out using binary solutions of hexane and ethanol in open environment, allowing the developing solvent been evaporated. Sudan III was developed with initial rapid advancing wicking front, while Acid Blue 9 was scarcely developed. On the other hand, Acid Blue 9 was developed with the readvancing second wicking front, while the spot of Sudan III scarcely migrated. Thus, the unexpected illusional phenomenon, overtaking the spot of Sudan III by the spot of Acid Blue 9, was observed. The readvancement of the second wicking front was found to be enhanced as increasing the relative humidity in the environment. Surface temperature of the chromatography paper was measured during the chromatographic development in open environment to show that it became lower than the dew point when the experiments were carried out in relatively high humidity. Solubility of Sudan III in a binary solution of ethanol and water remarkably decreased as increasing the content of water. It was thus suggested that the water vapor condensation to induce water mixing into the mobile phase to decrease the solubility of Sudan III to inhibit its chromatographic development to realize the illusional spot overtaking of dyes of their chromatographic development associated with solvent evaporation.
Assuntos
Compostos Azo , Benzenossulfonatos , Corantes , Hexanos , Corantes/análise , Solventes , Cromatografia Líquida de Alta Pressão/métodos , EtanolRESUMO
Removal of toxic dyes such as Rhodamine B is essential as it pollutes aqueous and soil streams as well. This comprehensive study explores the potential of Calophyllum inophyllum seed char as an efficient bio-adsorbent based on their characteristic properties and a comparative study between various carbon-based adsorbents on the adsorption capacity of Rhodamine B dye. In this study, the char was prepared from Calophyllum inophyllum seed using a slow pyrolysis process (298 K/min) at an optimum temperature of 823 K and used as an adsorbent for the removal of Rhodamine B from water. The resulting char was mesoporous and had 155.389 m2/g surface areas (BET) and 0.628 cc/g pore volume. The formation of pores was observed from the SEM analysis. The adsorption studies were tested and optimized through various parameters such as solution pH, adsorbent dosage, initial dye concentration, stirring speed, contact time, and solution temperature. Maximum 95.5 % removal of Rhodamine B was possible at the pH: 2, stirring speed: 100 rpm, time: 25 min, temperature 308 K, and dose: 1.2 g/L. The highest adsorption capacity at equilibrium was determined to be 169.5 (mg/g) through Langmuir adsorption isotherm studies and followed pseudo 2nd order kinetics. The thermodynamics study confirmed the adsorption processes were spontaneous (ΔG°=-0.735 kJ/mol) and endothermic (ΔH° = 4.1 kJ/mol) processes. The reusability study confirmed that the mesoporous char can be reused as an efficient adsorbent for up to 3 cycles for environmental remediation.
Assuntos
Carvão Vegetal , Corantes , Rodaminas , Poluentes Químicos da Água , Corantes/análise , Adsorção , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Termodinâmica , Água/química , CinéticaRESUMO
Good laboratory practice minimizes the biological hazard posed by potentially infectious casework samples. In certain scenarios, when the casework sample is contaminated with highly contagious pathogens, additional safety procedures such as disinfection might be advised. It was previously proven that ozone gas treatment does not hamper STR analysis, but there is no data on how the disinfection affects other steps of the forensic analysis. In this study, we aimed to assess the interference of ozone disinfection with forensic tests used to identify biological stains. A dilution series of blood, saliva, and semen samples were pipetted onto cotton fabric and let completely dry. Half of the samples were subjected to ozone treatment, while the rest served as controls. All the samples were tested with specific lateral flow immunochromatographic assays and for specific RNA markers with quantitative real-time PCR. Additionally, luminol test was carried out on blood spots, Phadebas® Amylase Test on saliva stains, and semen stains were examined with STK Lab kit and light microscope following Christmas Tree or Hematoxylin-Eosin staining. Ozone treatment had no detrimental effect on the microscopic identification of sperm cells. Undiluted blood samples were detected with luminol and immunoassay, but at higher dilution, the sensitivity of the test decreased after disinfection. The same decrease in sensitivity was observed in the detection of semen stains using STK Lab kit from STK® Sperm Tracker, and in the case of the immunoassay specific for prostate-specific antigen (PSA). Ozone treatment almost completely inhibited the enzymatic activity of amylase. The sensitivity of antibody-based detection of amylase was also greatly reduced. RNA markers showed degradation but remained detectable in blood and semen samples after incubation in the presence of ozone. In saliva, the higher Ct values of the mRNA markers were close to the detection limit, even before ozone treatment.
Assuntos
Manchas de Sangue , Saliva , Humanos , Masculino , Saliva/química , Sêmen , Corantes/análise , Luminol/análise , Desinfecção , Amilases/análise , RNA Mensageiro/análise , Coloração e Rotulagem , Medicina Legal/métodosRESUMO
The treatment of various organic pollutants from industrial wastewater using bio-based materials has gained significant attention owing to their excellent properties such as low-cost, eco-friendly, non-toxic, and biodegradability. In this perspective, casein (Cn), a protein-based biopolymer, was extracted from the cow milk as a low-cost adsorbent, and the adsorption performances were determined for the pristine Cn. The adsorbent was employed for the removal of two different classes of targeted pollutant anionic dyes such as Congo red (CR), Eriochrome Black T (EBT), Eosin Y (EY), and pharmaceutical waste i.e., diclofenac sodium (DS) and displayed better adsorption performances with the maximum adsorption capacity of 85.54, 31.72, 70.42 and 358.42 mg g-1 respectively. The interactions between Cn and pollutants are mainly ascribed to the electrostatic interaction, hydrogen bonding, hydrophobic interaction, and π-π interactions. Furthermore, to validate with realistic application the adsorbent proved with an excellent removal efficiency of 91.43% for fabric whitener i.e., Ujala Supreme®. These obtained results suggest that the Cn could be the potential adsorbent to effectively eliminate toxic pollutants from the aqueous solutions.