Methylene Blue Method Research Articles

Refined Surface Area Determination of Graphene Oxide Using Methylene Blue as a Probe Molecule: A Comparative Approach

Abstract In this research, we explored the effectiveness of the methylene blue (MB) adsorption method as an alternative approach for determining the specific surface area of graphene oxide (GO). Initially, through a comparative analysis with reference activated carbon (AC), we identified the limitations of utilizing N2 physisorption for specific surface area determination of GO. Our findings revealed that the standard pretreatment process (heating under vacuum) before N2 physisorption led to damage to the surface oxygen groups on GO, and the measured surface areas (43 m2/g) do not accurately represent the entire surface area. To optimize MB coverage on GO, we conducted adsorption equilibrium experiments, focusing on controlling temperature and pH. The pH was significantly important in regulating the coverage of MB. Under the optimized MB adsorption conditions, the specific surface area of GO was 1555 m2/g. Our assumptions regarding specific surface area calculations were supported by structural characterization of samples with varying MB uptakes. The results confirmed a uniform coverage of MB on GO by SEM-EDX, XRD, and AFM.

Exploring methylene blue as an effective alternative to radiotracer for sentinel lymph node biopsy in early breast cancer in resource-limited settings

Background: Sentinel lymph node biopsy is the recommended approach in the evaluation of axilla during breast cancer surgery. This study evaluated the results of patients who underwent methylene blue sentinel lymph node biopsy. Methods: The study included 35 female patients with T1, T2 and T3 tumours. 5 ml of 1% methylene blue was injected into the periareolar region. The axillary sentinel lymph node was found and removed, and axillary dissection was performed. The sentinel lymph node and axillary dissection specimen were histopathologically examined, and the results were compared. Results: The sentinel lymph node was found in 33 (90%) patients. There were no complications associated with the use of methylene blue dye. Methylene blue-stained sentinel nodes were histologically negative for malignancy in 42% and positive in 58% of patients. Corresponding to sentinel nodes, the final axillary staging was negative in 60% and positive in 40% of patients. On diagnostic accuracy parameters, the sensitivity of the methylene blue method in early breast cancer (cT1-3N0M0) patients was 90.47%, and the specificity was 100%. The PPV of the technique under study was found to be 100% and NPV was 85.71%. The accuracy rate was 93%, and the false negative rate was identified as 9.5%. Conclusions: Sentinel lymph node biopsy by methylene blue is a method that can be applied with high accuracy. Methylene blue can be considered as an alternative to radio colloid dye in sentinel lymph node biopsy in a limited resource setting.

Does gut microbiota dysbiosis impact the metabolic alterations of hydrogen sulfide and lanthionine in patients with chronic kidney disease?

BackgroundChronic Kidney Disease (CKD) is characterized by a methionine-related metabolic disorder involving reduced plasma levels of hydrogen sulfide (H2S) and increased lanthionine. The gut microbiota influences methionine metabolism, potentially impacting sulfur metabolite dysfunctions in CKD. We evaluated whether gut microbiota dysbiosis contributes to H2S and lanthionine metabolic alterations in CKD.MethodsThe gut microbiota of 88 CKD patients (non-dialysis, hemodialysis, and transplant patients) and 26 healthy controls were profiled using 16 S-amplicon sequencing. H2S and lanthionine concentrations were measured in serum and fecal samples using the methylene blue method and LC-MS/MS, respectively.ResultsThe CKD population exhibited a tenfold increase in serum lanthionine associated with kidney dysfunction. Despite lanthionine retention, hemodialysis and transplant patients had significantly lower serum H2S than healthy controls. Fecal H2S levels were not altered or related to bloodstream H2S concentrations. Conversely, fecal lanthionine was significantly increased in CKD compared to healthy controls and associated with kidney dysfunction. Microbiota composition varied among CKD groups and healthy controls, with the greatest dissimilarity observed between hemodialysis and transplant patients. Changes relative to the healthy group included uneven Ruminococcus gnavus distribution (higher in transplant patients and lower in non-dialysis CKD patients), reduced abundance of the short-chain fatty acid-producing bacteria Alistipes indistinctus and Coprococcus eutactus among transplant patients, and depleted Streptococcus salivarius in non-dialysis CKD patients. A higher abundance of Methanobrevibacter smithii, Christensenella minuta, and Negativibacillus massiliensis differentiated hemodialysis patients from controls. No correlation was found between differentially abundant species and the metabolic profile that could account for the H2S and lanthionine alterations observed.ConclusionsThe metabolic deregulation of H2S and lanthionine observed in the study was not associated with alterations in the gut microbiota composition in CKD patients. Further research on microbial sulfur pathways may provide a better understanding of the role of gut microbiota in maintaining H2S and lanthionine homeostasis.

Ultrasonic assisted adsorption of methylene blue using blood clam shell as a low-cost adsorbent

Methylene blue is a synthetic dye used in various industries, such as wood, linen, and silk. Generally, as much as 10–200 mg/L of methylene blue is released into the environment and potentially polluting the environment. One of methylene blue removal method from wastewater is adsorption, particularly using blood clam (Anadara granosa) shells adsorbent. Blood clam shells contain CaCO3 (up to 98.7 %) that can be utilized to adsorb methylene. Furthermore, methylene blue adsorption can be enhanced by employed the ultrasonic wave. This research aims to prepare, characterize, and employ blood clam shells as a low-cost adsorbent in the ultrasonic-assisted methylene blue adsorption. The parameters studied were the adsorbent preparation method, adsorbate pH, adsorbent mass, contact time, and initial concentration. The adsorbent preparation method affected the morphology, elemental composition, functional groups, and average particle size, which were confirmed using SEM-EDX, FTIR, and PSA, where this kind of investigation has never been conducted before. Optimum conditions for methylene blue adsorption were obtained for adsorbent A3, pH 12, adsorbent mass of 0.5 g, contact time of 60 min, and initial concentration of 10 ppm, with a removal percentage of 98.614 %. This removal percentage increased by 63.119 % (espescially in A3) compared to without ultrasonic waves, which could only remove methylene blue by 35.495 %. Ultrasonic-assisted adsorption of methylene blue using blood clam shells adsorbent proceeded according to the Sips isotherm model (R2 = 0.9953) and pseudo-second-order kinetics (R2 = 0.939). A3 shows an extraordinary performance, with reusability up to six cylces. The adsorption occurs by electrostatic interaction between adsorbent's surface and cations in methylene blue, chemisorption, and the formation of monolayer adsorbate in heterogenous A3's surface.

Agricultural low-cost waste adsorption of methylene blue and modelling linear isotherm method versus nonlinear prediction

AbstractThis study shows that geographically marked wheat hull, named Siyez, rice hull Sarı Kılçık, and Taşköprü Garlic stalk were used as agricultural waste to potential adsorbent materials for removing methylene blue from aqueous solution. Experimental data were evaluated in both equilibrium batch process and kinetic studies. In addition, the factors that affect the adsorption capacities, such as pH solutions, methylene blue concentration, contact time, and temperatures, were also investigated. Obtained data were subject to two constant adsorption models of Langmuir, Freundlich, Temkin, and Dubinin−Radushkevich. The kinetic models (pseudo-first-order, pseudo-second-order, intra-particle diffusion and film diffusion) and thermodynamic parameters were evaluated. The adsorption isotherms, characterized by an excellent fit with the Langmuir model (R2 = 0.99) across all adsorbents, underscore the prevalence of monolayer adsorption of methylene blue, in contrast to the Freundlich equation. Adsorption kinetics of the methylene blue onto the adsorbents followed pseudo-second-order kinetic model. According to high regression coefficient (R2) and minimal values of nonlinear error functions like RMSE; the maximum monolayer adsorption capacities of wheat hull, rice hull and garlic stalk were found to be 62.50 (mg/g), 54.94 (mg/g), and 370.37 (mg/g), respectively. The results indicated that these proposed adsorbents could be low-cost and effective adsorbents for water purification and have adsorption capacity as much as comparable with the literature. In batch equilibrium studies, the adsorption of methylene blue dye onto the wheat hull, rice hull, and garlic stalk exhibited a significant correlation with temperature, contact time, and initial concentration of methylene blue dye and Adaptive Neuro-Fuzzy Inference System algorithm for forecasting overall the system parameter well fitted with these findings with the accuracy of outputs (R2 about 0.99 for each). Consequently, the thermodynamic analysis revealed that the adsorption process takes place in bulk diffusion by liquid phase mass transfer and occurred spontaneously with endothermically except garlic stalk. Adsorption thermodynamic studies show that the adsorption of methylene blue onto the garlic stalk was spontaneous and exothermic. Graphical Abstract

Enrichment of Polycyclic Aromatic Hydrocarbon (PAH)-Degrading Strictly Anaerobic Sulfate-Reducing Cultures from Contaminated Soil and Sediment.

Sulfate-reducing bacteria (SRB) are crucial players in global biogeochemical cycling and some have been implicated in the anaerobic biodegradation of organic pollutants, including recalcitrant and hazardous polycyclic aromatic hydrocarbons (PAHs). Obtaining PAH-degrading SRB cultures for laboratories is of paramount importance in the development of the young field of anaerobic biodegradation of PAHs. SRB grow exceptionally slowly on PAH substrates and are highly sensitive to oxygen. Consequently, enrichment and maintenance of PAH-degrading SRB cultures and characterization of the biodegradation process remain a tedious and formidable task, especially for new researchers. To address these technical constraints, we have developed robust and effective protocols for obtaining and characterizing PAH-degrading SRB cultures. In this set of protocols, we describe step-by-step procedures for preparing inocula from contaminated soil or sediment, preparing anoxic medium, establishing enrichment cultures with PAHs as substrates under completely anaerobic sulfate-reducing conditions, successive culture transfers to obtain highly enriched cultures, rapid verification of the viability of SRB in slow-growing cultures, assessment of PAH degradation by extracting residuals using organic solvent and subsequent analysis by gas chromatography-mass spectrometry, and spectrophotometric determination of sulfate and sulfide in miniaturized, medium-throughput format. These protocols are expected to serve as a comprehensive manual for obtaining and characterizing PAH-degrading sulfate-reducing cultures. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Obtaining PAH-degrading strictly anaerobic sulfate-reducing enrichment cultures from contaminated soil and sediment Support Protocol 1: Operation and maintenance of an anaerobic workstation Support Protocol 2: Setup of gas purging systems for preparing anoxic solutions Support Protocol 3: Verification of viability in slow-growing SRB enrichment cultures Support Protocol 4: Extraction of genomic DNA from low-biomass cultures Basic Protocol 2: Extraction of residual PAH from liquid culture and analysis by GC-MS Basic Protocol 3: Spectrophotometric determination of sulfate concentration in SRB cultures Basic Protocol 4: Spectrophotometric determination of sulfide concentrations in SRB cultures by the methylene blue method Alternate Protocol: Spectrophotometric determination of sulfide concentrations in SRB cultures by the colloidal copper sulfide method.

Aptamer-enabled electrochemical bioplatform utilizing surface-modified g-C3N4/MoS2/PANI nanocomposite for detection of CA125 biomarker

Detecting ovarian cancer at an early stage is crucial for enhancing patient outcomes, underscoring the demand for an efficient and non-invasive detection method. Cancer antigen 125 (CA125) is a vital biomarker in ovarian cancer detection, and there is a pressing demand to develop a quick, sensitive, and simple detection method. Nanobiosensors are increasingly being used by scientists due to their high selectivity and sensitivity, allowing for the swift and precise detection of a wide range of biomarkers. This study aimed to design and fabricate an electrochemical nanobiosensor that could accurately and selectively detect CA125. The nanobiosensor employed graphitic carbon nitrides, molybdenum disulfide, and polyaniline (g-C3N4/MoS2/PANI) to stabilize aptamer strands on a modified glassy carbon electrode. The aptasensor was used to perform electrochemical detection of labeled CA125, utilizing methylene blue and label-free ferrocyanide methods. Ferrocyanide and methylene blue detection limits were determined to be 0.196 U.mL−1 for ferrocyanide and 0.196 U.mL−1 for methylene blue, with a linear detection range of 2–10 U.mL−1 for linear detection. The study results showed that the modified electrode exhibited high selectivity towards CA125 and superior stability compared to other biomolecules. The electrochemical aptasensor also displayed impressive performance when analyzing the serum of patients and healthy people. These findings hold significant promise for future investigation in ovarian cancer diagnosis. This novel electrochemical nanobiosensor may aid in the early detection and management of ovarian cancer, ultimately leading to better patient outcomes.

The impact of methylene blue in colon cancer: a retrospective multicentric study

IntroductionDiscussions about the optimal lymph node (LN) count and its therapeutic consequences have persisted over time. The final LN count in colorectal tissues is affected by a variety of variables (patient, tumor, operation, pathologist, immune response). Methylene blue (MB) intra-arterial injection is a simple and inexpensive procedure that can be used to enhance lymph node count.AimAnalyze whether there is a statistically significant difference between intra-arterial methylene blue injection and conventional dissection for the quantification of lymph nodes and determine if there is a variation in the quality of lymph node acquisition.Methods and resultsBetween 2015 and 2022, we conducted a retrospective analysis of colon cancer specimens. Data on the tumor’s features, the number of lymph nodes, the number of lymph nodes that were positive, and other factors had been collected. The number of identified lymph nodes was highly significantly improved in the study group (P < 0.05). There is not a significant statistical difference between groups regarding the metastatic lymph node harvest. The group with injection of intra-arterial methylene blue shows a significantly decreased (P < 0.05) of the of cases with less than 12 lymph nodes recovered comparing with the control group.ConclusionColon cancer specimens can be easily evaluated concerning lymph nodes using the methylene blue method. Therefore, we strongly advise this approach as a standard procedure in the histological evaluation of colon cancer specimens in order to maximize the identification of lymph nodes. However, the detection of metastatic lymph nodes was unaffected significantly.

Comprehensive study on physico-chemical soil analysis for optimizing paddy (Oryza sativa L.) cultivation in Kamrup (Metro) district of Assam, India

Rice being the staple food in Assam, its productivity should be increased for the availability of the common people. The main objective of this study is to compare the qualities of soil samples and to correlate the results with the production (per year) of paddy (Oryza sativa) from 3 different studied areas. The soil samples were collected during March-May, 2023. The oven dry method and drying and weighing method are used to determine bulk and particle densities respectively. The electrical conductivity and pH of the soil samples are determined using a benchtop conductivity meter and pH meter. Walkley-Black chromic acid wet oxidation method and methylene blue method are used to determine the organic carbon and cation exchange capacity (CEC) of soil samples respectively. Nitrogen, phosphorus, and potassium of the soil samples are estimated using the instrument Mridaparikshak. The moisture content, bulk density, particle density, soil porosity, cation exchange capacity (CEC), pH, electrical conductivity, nitrogen, P2O5, and K2O are observed in the range of 24.69 % to 39.42 %, 1.12 g cm-3 to 1.25 gcm-3, 1.83 gcm-3 to 1.99 g/cm-3, 33 to 43, 2.8 × 10-5mol dm-3to 11.7x10-5 mol dm-3, 7.4 to 8, 0.23 dS/m to 0.40 dS/m, 0.645% to 1.49%, 213.20 kg/ha - 235.14 kg/ha, 17.92 kg/ha - 20.44 kg/ha and 148.92 kg/ha -164.45 kg/ha respectively. The soil characterized by moisture content =27.52 %, bulk density=1.25 gcm-3, particle density =1.86 g cm-3, porosity =33%, cation exchange capacity =11.7 x 10-5 mol dm-3, pH {(1:5) at 210C} = 7.9, electrical conductivity = 0.40 dS/m, organic carbon =0.825 %, organic matter =1.42 %, N =235.14 kg/ha, P2O5 = 20.44 kg/ha and K2O =164.45 kg/ha showed good yield.

Surface modification of polyester fabrics using choline hydroxide-catalysed glycolysis

This study explores the surface modification of polyethene terephthalate (PET) fabric via glycolysis, employing choline hydroxide as an eco-friendly catalyst. A range of chemicals was evaluated for catalysing the glycolysis reaction. Among them, choline hydroxide demonstrated notable enhancements in surface hydrophilicity, moisture regain, wicking properties, and water contact angle, surpassing other catalysts. Scanning Electron Microscopy (SEM) revealed a marked increase in surface roughness and irregularities following glycolysis in the presence of this ionic liquid. The surface modification technique employed in this investigation resulted in a decrease of less than 20% in the breaking force of the fabric. Fourier Transform Infrared (FT-IR) spectroscopy and the methylene blue staining method confirmed the emergence of free hydroxyl groups on the modified fabric's surface. These findings suggest that glycolysis catalysed by choline hydroxide is a promising approach for enhancing the surface characteristics of polyester fabrics, which may lead to improved functional properties in textile applications.

Exploring the Role of Serum Hydrogen Sulphide (H2S) Levels in Manic Depressive Psychosis in Terms of Its Association, Diagnostic Ability, and Severity Prediction: Findings From a Tertiary Care Center in North Bengal.

Manic depressive psychosis (MDP) or bipolar disorder, a prevalent psychiatric condition globally and in the Indian population, has been attributed to various pathological mechanisms. Hydrogen sulphide (H2S), a member of the gasotransmitter family, may be linked to the development of bipolar disorder because it plays a crucial role in maintaining proper neuronal function in terms of excitability, plasticity, and homeostatic functions. There is very little data regarding the role of the gasotransmitter H2S in MDP in terms of its association, diagnostic ability, and severity prediction, which led us to conduct this study among MDP patients in the Sub-Himalayan region of West Bengal. This was an observational case-control study performed in the Department of Biochemistry, North Bengal Medical College and Hospital, Siliguri, West Bengal, India, from January 2022 to December 2022. Fifty diagnosed MDP patients and 50 healthy age- and sex-matched control subjects satisfying the inclusion and exclusion criteria were studied. The H2S level in the blood was assayed using the standardised spectrophotometric methylene blue method. The severity of depression was assessed by Hamilton Depression Rating Scale (HAM-D) scoring. Of the 50 MDP patients, 45 (90%) were in the depressive phase, and five (10%) were in the manic phase. Of the 45 depressive patients, eight (17.8%) had mild depression, 12 (26.7%) had moderate depression, 19 (42.2%) had severe depression, and six (13.3%) had very severe depression. The mean H2S level in MDP patients (41.98±18.88 μmol/l) was significantly (P<0.05) lower than that in control subjects (99.20± 15.20 μmol/l). It was also observed that the mean H2S level in MDP patients decreased with the duration of the disease but was not statistically significant. The mean H2S levels in the different depression severity groups were found to be significantly different (P<0.001). Receiver operating characteristic (ROC) curve analysis revealed that a cut-off value of H2S <78.5 μmol/l was associated with MDP, with a sensitivity of 96%and a specificity of 88%,and a cut-off value of H2S < 53 μmol/lpredicted the severity of depression with a sensitivity of 89.3% and a specificity of 76.5%. The significant association of the gasotransmitter H2S in MDP patients and its role as a diagnostic and severity predictive marker can help us to employ proper measures for better management of MDP and improving quality of life.

Effects of common dissolved anions on the efficiency of Fe0-based remediation systems

Quiescent batch experiments were conducted to evaluate the influences of Cl−, F−, HCO3−, HPO42−, and SO42− on the reactivity of metallic iron (Fe0) for water remediation using the methylene blue (MB) method. Strong discoloration of MB indicates high availability of solid iron corrosion products (FeCPs). Tap water was used as an operational reference. Experiments were carried out in graduated test tubes (22 mL) for up to 45 d, using 0.1 g of Fe0 and 0.5 g of sand. Operational parameters investigated were (i) equilibration time (0–45 d), (ii) 4 different types of Fe0, (iii) anion concentration (10 values), and (iv) use of MB and Orange II (O-II). The degree of dye discoloration, the pH, and the iron concentration were monitored in each system. Relative to the reference system, HCO3− enhanced the extent of MB discoloration, while Cl−, F−, HPO42−, and SO42− inhibited it. A different behavior was observed for O-II discoloration: in particular, HCO3− inhibited O-II discoloration. The increased MB discoloration in the HCO3− system was justified by considering the availability of FeCPs as contaminant scavengers, pH increase, and contact time. The addition of any other anion initially delays the availability of FeCPs. Conflicting results in the literature can be attributed to the use of inappropriate experimental conditions. The results indicate that the application of Fe0–based systems for water remediation is a highly site-specific issue which has to include the anion chemistry of the water.

Volumetric surface area of natural coarse aggregates by interferometry-3D scanning (microscale) method

Surface (microscale) roughness of coarse aggregates influence the cement suspension’ viscosity and the interfacial bonding strength of concrete, but its characterization method is not consolidated and still a research challenge. 3D scanner determines accurately the shape, volume, but it is incapable of describing the roughness at microscale. Roughness at microscale (surface index – cm2/cm2) can be measured accurately using interferometry, but it cannot describe shape and volume of the particles. Once the volume of aggregate particles may vary 200% and it seems crucial to establish the (micro)roughness per volume (cm2/cm3) to better understand the effects in the properties of cementitious materials. This paper presents a method of obtaining volumetric surface area of coarse aggregates at micrometric scale by joining (cm2/cm3) both techniques. Three types of aggregates were assessed: gneiss, low-grade meta-carbonate (dolomite) and quartzite (gravel), with one hundred particles in the size range of 4.75 mm to 37.5 mm. For coarse aggregates, the larger the particles, the more of their surface area will be influenced by (mesoscale) shape and less by surface (microscale) roughness. However, the smaller the particles, SI index will differ considerably. The surface area determined by the method proposed in this paper provides a good correlation with the methylene blue method.

Visualization Methods for Uterine Sentinel Lymph Nodes in Early-Stage Endometrial Carcinoma: A Comparative Analysis.

Sentinel lymph node (SLN) biopsy in early-stage endometrial cancer is recommended over systematic lymphadenectomy due to reduced morbidity and comparable detection rates. The main objective of this study was to compare the overall and bilateral detection rates of SLN in early-stage endometrial cancer using three techniques. a prospective cohort study was designed to detect the difference in SLN detection rate in three cohorts: Indocyanine green (ICG), methylene blue (MB), and tracer combination (ICG + MB). Mapping characteristics, detection rate, number of SLNs, and positive SLNs of the three cohorts were compared. A total of 99 patients were enrolled. A total of 109 SLN sites with 164 lymph nodes were detected. No differences were found between the three cohorts in terms of age, BMI, tumor diameter, or other histologic characteristics. The overall SLN detection rate (DR) was 54.3% in the MB group, 72.7% in ICG, and 80.6% in the ICG-MB group. Bilateral DR was 22.9%, 39.4%, and 54.8% in groups, respectively, with the MB method yielding significantly inferior results. The ICG-MB group demonstrated superior overall and bilateral detection rates, but a significant difference was found only in the MB cohort. Combining tracer agents can enhance the accuracy of SLN identification in initial-stage endometrial cancer without additional risk to the patient.

Adsorption of Lead Metal Ions in Solution with Diphenylcarbazide Modified Silica Gel

Silica gel is one of the adsorbents whose surface is easy to modify and can be used in the adsorption of heavy metal ions. This study aims to modify silica gel with diphenylcarbazide and use it as an adsorbent for Pb2+ metal ions. The modification was carried out by impregnation of silica gel with diphenylcarbazide solution at a ratio of 1 gram of silica gel and 1 mmol of diphenylcarbazide. Characterization with IR spectrophotometry to analyze the functional groups formed on the modified silica gel and the initial silica gel, acid-base titration to determine the surface acidity, and methylene blue method to determine the surface area of ??the two silica gels. . The results showed that the modification of silica gel with diphenylcarbazide had been successfully made, indicated by the appearance of the absorption band of the N-H group at ±3375.43 cm-1, aromatic C-H at ±3032.10 cm-1 and C=O at 1658.78 cm-1. , which are groups derived from diphenylcarbazide, and the absorption band of the Si-O-Si group at ±1203.58 cm-1, the Si-OH group at 912.33 cm-1, and the –OH group in the wave number range of 3600 -3400 cm-1, which is the main group of silica gel. Diphenylcarbazide-modified silica gel experienced an increase in surface acidity from 0.5205 to 0.8133 mmol/g, and a slight increase in surface area from 46.1057 to 46.1613 m2/g. Adsorption of diphenylcarbazide modified silica gel on Pb2+ metal ions in optimum solution occurred at pH 3, contact time 10 minutes, and initial concentration of Pb2+ 300 mg/L, with an adsorption capacity of 52.6264 mg/g. The adsorption that occurs follows the Langmuir isotherm.

Synthesis of Activated Carbon from Cassava Peeling and Its Applications for Removal of Methylene Blue

The present work aims to increase the value of cassava peelings by its transformation in activated carbon. The activated carbon was prepared by chemical activation using 40% of phosphoric acid solution as activation agent with an impregnation rate equal to 1.5 g of acid/g of precursor. The carbonization was carried out at 400°C for 90 minutes. Bohem titration and the Lopez-Ramon method were used to determine the chemical characteristics of the prepared activated carbon (ACCP), while surface area of the sample was estimated by methylene blue and iodine index methods. The best kinetic model that describes the adsorption reaction of MB on ACCP activated carbon is the pseudo-second-order model. Adsorption isotherm was also evaluated. Activated carbon (ACCP) has the following characteristics: pH&amp;lt;SUB&amp;gt;PZC&amp;lt;/SUB&amp;gt;= 3.9; Iodine index value equal to 914.4 mg/g and methylene blue index value equal to 643.72 mg/l. ACCP has more acid functions (5.95 meq/g) than basic function (1.3 meq/g). The “batch method” was used for pollutant removal and it reveals that the contact time value is equal to 40 minutes. The influence of activated carbon mass on its methylene blue adsorption capacity was studied. The experimental data are in agreement with the Langmuir and Freundlich isotherm models. The maximum adsorption capacity obtained using Langmuir isotherm model was 75.93 mg/g.

Activated sodium bentonite as an adsorbent for efficient removal of hexavalent chromium: Statistical optimization using Box–Behnken design

AbstractAt present, developing countries, including Ethiopia, are undergoing a phase of industrial transformation. As a result, there has been a significant rise in the presence of harmful pollutants in groundwater. The release of deleterious heavy metals, such as Cr (VI), into the surrounding ecosystem is a result of various industrial operations. The present investigation utilized activated sodium bentonite clay as an adsorbent agent to facilitate the elimination of Cr (VI). The clay was subjected to acidification and thermal modification techniques to enhance its adsorption capacity. The investigation involved an examination of the particular surface area, capacity for cation exchange, crystalline properties, functional groups on the surface, and structural morphology. The methylene blue test method was employed to ascertain the maximum specific surface area and cation exchange capacity of the adsorbent, which were found to be 512 m2/g and 65.5 meq/100 g, respectively. The clay mineral composition was analyzed using X‐ray diffraction, which indicated that the primary constituent was montmorillonite. The presence of impurities such as quartz, feldspar, muscovite, cristobalite, and hematite was also detected. The study employed response surface methodology, Box–Benkhen design (RSM‐BBD) to investigate the impact of operational parameters, including agitation time, initial Cr (VI) concentration, and adsorbent dosage. Under the optimal conditions, a removal efficiency of 98.05% was achieved for Cr (VI) for a contact duration of 120 min, a dosage of 3.913 g/L, and an initial concentration of 50 mg/L. The sodium bentonite clay that was activated demonstrated a maximum capacity for adsorption of 22.72 mg/g in regards to the adsorption of Cr (VI). The experimental data were best fitted by the Langmuir isotherm, which exhibited a correlation coefficient of 0.9699. The adsorption kinetics were assessed and determined to adhere to a pseudo‐second‐order pattern, exhibiting a coefficient of determination (R2) value of 0.999. Furthermore, the activated sodium bentonite clay demonstrated remarkable potential for repeated utilization in the adsorption of Cr (VI) ions in aqueous solutions.

Novel protocol for fouling detection of reverse osmosis membrane based on methylene blue colorimetric method by image processing technique.

In the current study, a novel methylene blue (MB)-based colorimetric method for a quick, inexpensive, and facile approach for the determination of fouling intensity of reverse osmosis (RO) membrane has been reported. This technique is based on the interaction of MB with the organic foulants and shows the corresponding change in the colour intensity depending on the severity of fouling. The organic foulants, such as albumin, sodium alginate, and carboxymethyl cellulose (CMC), were chosen as model foulants, and the membranes were subjected to foul under extreme fouling conditions. The fouled membranes underwent an MB treatment followed by image-processing analyses. The severity of surface fouling of membranes was evaluated in terms of fouling intensity and correlated with the corresponding decline of permeate flux. The maximum fouling intensity of the albumin, sodium alginate, and CMC sodium were found to be 8.83, 23.38, and 9.19%, respectively, for the definite concentration of foulants. The physico-chemical interactions of the given foulants and MB were confirmed by changes in zeta potentials and increased sizes of the foulant by the dynamic light scattering technique. The surface fouling over the membrane surface was confirmed by the characterization of membranes.

QUANTIFICATION OF SODIUM DEOXYCHOLATE IN PROTEOMICS SAMPLE PREPARATION USING METHYLENE BLUE

Anionic detergents like SDC are commonly used in biochemical and molecular biology research for solubilizing and separating proteins and nucleic acids. The detection method using methylene blue (MB) can be employed to determine the concentration of anionic detergents in these experimental preparations. The quantification protocol for surface active substances was optimized, with the consideration of factors such as pH, salts and the spectrophotometer wavelength. Several extraction methods were employed to remove the detergent from the sample, namely, ethyl acetate extraction, mineral oil and acid precipitation. All of the methods have about the same efficiency. The MB method was used as a standard technique for the precise quantification of detergent amounts which allowed as achieving an approximate concentration range between the lower limit of ca. 0.02% and 0.1% of the upper limit. Consequently, we weren’t able to detect the concentration of the detergent lower than 0.02%. In the presence of anionic detergents, the electrostatic interaction between positively charged MB and the anions forms a complex that can be extracted into chloroform, allowing for quantification. Without the formation of this complex, water-soluble MB remains immiscible in chloroform.

Dissolving sodium hydrosulfide in drinking water is not a good source of hydrogen sulfide for animal studies

Hydrogen sulfide (H2S) has many physiological and pathological roles in the human body. Sodium hydrosulfide (NaHS) is widely used as a pharmacological tool for assessing H2S effects in biological experiments. Although H2S loss from NaHS solution is a matter of minutes, some animal studies use NaHS in solution as an H2S-donating compound in drinking water. This study addresses whether 30 μM NaHS in drinking water prepared in rat/mouse water bottles remains stable for at least 12–24 h, as presumed by some authors. NaHS solutions (30 μM) were prepared in drinking water and immediately transferred to rat/mice water bottles. Samples were obtained from the tip of water bottles and from inside of the bottles at 0, 1, 2, 3, 4, 5, 6, 12, and 24 h for sulfide measurement using the methylene blue method. Furthermore, NaHS (30 μM) was administered to male and female rats for two weeks, and serum sulfide concentrations were measured every other day in the first week and at the end of the second week. NaHS solution was unstable in the samples obtained from the tip of water bottles; it declined by 72% and 75% after 12 and 24 h, respectively. In the samples obtained from the inside of the water bottles, the decline in the NaHS was not significant until 2 h; however, it decreased by 47% and 72% after 12 and 24 h, respectively. NaHS administration did not affect serum sulfide levels in male and female rats. In conclusion, NaHS solution prepared in drinking water can not be used for H2S donation as the solution is unstable. This route of administration exposes animals to variable and lower-than-expected amounts of NaHS.