sodium-dodecyl-sulfate and malachite-green

The synthesis of a novel composite adsorbent prepared from coir pith activated carbon (CPAC), chitosan and sodium dodecyl sulphate (SDS, an anionic surfactant) is reported. The characterisation of the composite was done using SEM, XRD, UV-visible and IR spectroscopy studies. The effectiveness of the composite was made for the removal of a toxic cationic dye, malachite green (MG) from waste water based on adsorption studies. The reaction conditions for the adsorption studies were optimized based on initial dye concentration, dose rate, reaction time, pH and temperature. Langmuir and Freundlich isotherm models were adopted to study the mechanism of adsorption. The adsorption process was found to follow pseudo second order kinetics. The results of the present study indicate that the CPAC based composite could be an effective low cost adsorbent for the removal of MG from waste water.

Topics: Adsorption; Chitosan; Hydrogen-Ion Concentration; Kinetics; Rosaniline Dyes; Sodium Dodecyl Sulfate; Solutions; Surface Properties; Thermodynamics; Time Factors; Wastewater; Water; Water Pollutants, Chemical; Water Purification

We studied the activity of the fluorescently labeled membrane transporter MalGFK(2), which transports maltose at the expense of ATP hydrolysis. We used a commercially available malachite green assay (SensoLyte MG phosphate assay kit; Anaspec) to quantify the liberated phosphate upon ATP hydrolysis. However, strong variations in phosphate concentration were measured when using the supplier's handling protocol. We optimized the protocol, taking into account the effects mediated by glycerol, SDS, and fluorescent label on the sample. As a result we obtained highly reproducible phosphate concentration values under conditions optimal for solubilized membrane proteins.

Topics: Adenosine Triphosphate; Biological Products; Glycerol; Hydrolysis; Membrane Proteins; Phosphates; Rosaniline Dyes; Sodium Dodecyl Sulfate

This paper reports the use of polyurethane foam (PUF) as solid support for diffuse reflectance spectrophotometric determination of Malachite Green (MG), a well known cationic dye used as biocide in the aquaculture industry, using sodium dodecylsulfate (SDS) as a counter ion. The method was based on the formation of an ionic-pair between the dye and the anionic surfactant SDS, which was sorbed onto PUF surface, where the diffuse reflectance was measured at 635 nm. Several parameters that could affect the performance of the system were evaluated. As expected, the SDS concentration presented strong influence on the analytical signal because the PUF was able to retain only the ionic-pair. The pH influenced the analytical signal, which was more intense in the acidic/neutral range, while the ionic strength only influenced the kinetic of the MG (as MG-SDS ionic-pair) sorption. The methodology was employed in the determination of MG in river waters and a recovery test was performed to test the accuracy of the procedure. Recovery percentages between 98.7 and 107% were observed when 60 or 80 μg L(-1) of MG were added to the samples.

Topics: Adsorption; Hydrogen-Ion Concentration; Ions; Osmolar Concentration; Polyurethanes; Rivers; Rosaniline Dyes; Sodium Dodecyl Sulfate; Water Pollutants, Chemical

A miniaturized methodology for the determination of phosphate in waters has been developed by combining directly suspended droplet microextraction (DSDME) with microvolume spectrophotometry. The method is based on the extraction of the ion pair formed between 12-molybdophosphate and malachite green onto a microdrop of methyl isobutyl ketone and subsequent spectrophotometric determination with no dilution. An enrichment factor of 325 was obtained after 7.5 min of microextraction. The detection limit was 6.1 nM phosphate and the repeatability, expressed as relative standard deviation, was 2.7% (n=6). The method was successfully applied to the determination of dissolved reactive phosphorus in different freshwater samples.

Topics: Chemical Fractionation; Miniaturization; Phosphates; Reproducibility of Results; Rosaniline Dyes; Sodium Chloride; Sodium Dodecyl Sulfate; Solvents; Spectrophotometry, Ultraviolet; Time Factors; Trityl Compounds; Water

The P27-P55 (lprG-Rv1410c) operon is crucial for the survival of Mycobacterium tuberculosis, the causative agent of human tuberculosis, during infection in mice. P55 encodes an efflux pump that has been shown to provide Mycobacterium smegmatis and Mycobacterium bovis BCG with resistance to several drugs, while P27 encodes a mannosylated glycoprotein previously described as an antigen that modulates the immune response against mycobacteria. The objective of this study was to determine the individual contribution of the proteins encoded in the P27-P55 operon to the resistance to toxic compounds and to the cell wall integrity of M. tuberculosis.. In order to test the susceptibility of a mutant of M. tuberculosis H37Rv in the P27-P55 operon to malachite green, sodium dodecyl sulfate, ethidium bromide, and first-line antituberculosis drugs, this strain together with the wild type strain and a set of complemented strains were cultivated in the presence and in the absence of these drugs. In addition, the malachite green decolorization rate of each strain was obtained from decolorization curves of malachite green in PBS containing bacterial suspensions.. The mutant strain decolorized malachite green faster than the wild type strain and was hypersensitive to both malachite green and ethidium bromide, and more susceptible to the first-line antituberculosis drugs: isoniazid and ethambutol. The pump inhibitor reserpine reversed M. tuberculosis resistance to ethidium bromide. These results suggest that P27-P55 functions through an efflux-pump like mechanism. In addition, deletion of the P27-P55 operon made M. tuberculosis susceptible to sodium dodecyl sulfate, suggesting that the lack of both proteins causes alterations in the cell wall permeability of the bacterium. Importantly, both P27 and P55 are required to restore the wild type phenotypes in the mutant.. The results clearly indicate that P27 and P55 are functionally connected in processes that involve the preservation of the cell wall and the transport of toxic compounds away from the cells.

Topics: Anti-Infective Agents; Bacterial Proteins; Blotting, Western; Cell Membrane; Cell Survival; Cell Wall; Drug Resistance, Microbial; Electrophoresis, Polyacrylamide Gel; Ethambutol; Ethidium; Isoniazid; Lipoproteins; Membrane Transport Proteins; Microbial Sensitivity Tests; Mutation; Mycobacterium tuberculosis; Operon; Rosaniline Dyes; Sodium Dodecyl Sulfate

We have employed a high-sensitivity off-line coupled with on-line preconcentration method, cloud-point extraction (CPE)/cation-selective exhaustive injection (CSEI) and sweeping-MEKC, for the analysis of malachite green. The variables that affect CPE were investigated. The optimal conditions were 250 g/L of Triton X-100, 10% of Na(2)SO(4) (w/v), heat-assisted at 60 degrees C for 20 min. We monitored the effects of several of the CSEI-sweeping-MEKC parameters - including the type of BGE, the concentrations of SDS, the injection length of the high-conductivity buffer, and the injection time of the sample - to optimize the separation process. The optimal BGE was 50 mM citric acid (pH 2.2) containing 100 mM SDS. In addition, electrokinetic injection of the sample at 15 kV for 800 s provided both high separation efficiency and enhanced sweeping sensitivity. The sensitivity enhancement for malachite green was 1.9 x 10(4) relative to CZE; the coefficients of determination exceeded 0.9928. The LOD, based on an S/N of 3:1, of CSEI-sweeping-MEKC was 0.87 ng/mL; in contrast, when using off-line CPE/CSEI-sweeping-MEKC the sensitivity increased to 69.6 pg/mL. This proposed method was successfully applied to determine trace amounts of malachite green in fish water samples.

Topics: Animals; Cations; Chemical Fractionation; Chromatography, Micellar Electrokinetic Capillary; Citric Acid; Ethanol; Fishes; Fresh Water; Reproducibility of Results; Rosaniline Dyes; Sensitivity and Specificity; Sodium Dodecyl Sulfate; Sulfates; Surface-Active Agents; Temperature

This paper reports the development of a new procedure for the adsorption of four cationic dyes (Rhodamine B, Methylene Blue, Crystal Violet and Malachite Green) from aqueous medium employing polyurethane foam (PUF) loaded with sodium dodecylsulfate (SDS) as solid phase. PUF loading process was based on the stirring of 200mg PUF cylinders with acidic solutions containing SDS. The conditions for loading were optimized by response surface methodology (RSM) using a Doehlert design with three variables that were SDS and HCl concentrations and stirring time. Results obtained in the optimization process showed that the stirring time is not a relevant parameter in the PUF loading, evidencing that the transport of SDS from solution to PUF surface is fast. On the other hand, both SDS and HCl concentrations were important parameters causing significant variation in the efficiency of the resulting solid phase for the removal of dyes from solution. At optimized conditions, SDS and HCl concentrations were 4.0 x 10(-4) and 0.90 mol L(-1), respectively. The influence of stirring time was evaluated by univariate methodology. A 20 min stirring time was established in order to make the PUF loading process fast and robust without losing efficiency. The procedure was tested for the removal of the four cationic dyes from aqueous solutions and removal efficiencies always better than 90% were achieved for the two concentrations tested (2.0 x 10(-5) and 1.0 x 10(-4)mol L(-1)).

Topics: Adsorption; Coloring Agents; Gentian Violet; Methylene Blue; Polyurethanes; Rhodamines; Rosaniline Dyes; Sodium Dodecyl Sulfate; Solutions; Water

Surface of alumina was modified with sodium dodecyl sulfate (SDS), an anionic surfactant. The surfactant-modified alumina (SMA) was characterized by FTIR and thermal analysis. The SMA was then used for the removal of malachite green (MG; Basic Green 4), a well-known toxic cationic dye from aqueous environment. The removal of MG takes place in the micellar structure formed on alumina surface, and the process is called adsolubilization. All the studies were carried out in batch mode. The kinetic studies showed that 1 h contact time was sufficient to attain equilibrium. SMA was very efficient to remove MG up to 99% under optimum conditions. The concentration range of MG was 20-100 mg/L. The isotherm studies showed that it follows Langmuir model better than the Freundlich model. The maximum adsorption capacity was 185 mg/g. The effects of various parameters such as pH, presence of interfering ions (Cl-, NO3-, H2PO4-, SO4(2-), Fe2+, Ca2+) and organics (pesticides such as 2,4-dichlorophenoxyacetic acid, atrazine, endosulfan, and humic acid) are evaluated. It was observed that H2PO4-, Fe2+, endosulfan, and humic acid have maximum interference. Desorption of MG from exhausted SMA using acetone, and its reuse was studied. The regenerated adsorbent shows approximately 80% efficiency on the removal of MG. The usability of SMA for the removal of MG from real wastewater was also examined. The kinetic equilibrium was attained within 1 h and the removal could be achieved up to approximately 95% at a dose of 20 g/L. The adsorption followed Freundlich isotherm model better than the Langmuir model.

Topics: Adsorption; Aluminum Oxide; Differential Thermal Analysis; Models, Chemical; Molecular Structure; Rosaniline Dyes; Sodium Dodecyl Sulfate; Spectroscopy, Fourier Transform Infrared; Surface Properties; Surface-Active Agents; Water Pollutants, Chemical; Water Purification

In sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) according to the method of Weber and Osborn, protein bands are often distorted by tailing at both ends, and the phenomenon is often called "edge tailing." This was eliminated by adding glycerol at a concentration of 10-15% (v/v) to the sample-well gel supplemented to form the sample wells. This simple modification made the protein bands as sharp and straight as those in SDS-PAGE according to the Laemmli procedure. The linearity of the semilogarithmic plot of mobilities versus molecular mass was better than that obtained by Laemmli-type SDS-PAGE.

Topics: Cytochrome c Group; Electrophoresis, Polyacrylamide Gel; Glycerol; Proteins; Rosaniline Dyes; Sodium Dodecyl Sulfate

A simple and sensitive colorimetric assay for protein phosphatase activity based on the determination of released Pi by an improved malachite green procedure (A. A. Baykov, O. A. Evtushenko, and S.M. Avaeva, 1988, Anal. Biochem. 171, 266-270) is described. Proteins must be removed or stabilized prior to Pi determination with 0.25 N sulfuric acid or 3% (w/w) perchloric acid. Alternatively, to avoid possible acid hydrolysis of phosphate groups from organic compounds during deproteinization, the protein present in the phosphatase assay mixture can be stabilized with sodium dodecyl sulfate. In this case, the excess detergent is subsequently removed by precipitation with KCl because it colors with the malachite green reagent. The above procedure was applied to the determination of phosphorylase phosphatase activity in bovine brain extracts and the results are comparable to those obtained with the radioisotopic phosphatase assay.

Topics: Animals; Chemical Precipitation; Colorimetry; Kinetics; Muscles; Perchlorates; Phosphates; Phosphorylase a; Phosphorylase b; Rabbits; Rosaniline Dyes; Sodium Dodecyl Sulfate; Solutions; Sulfuric Acids