Presence Of Brij-35 Research Articles

Flow-injection determination of manganese (II) using surfactant enhanced diperiodatonickelate (IV)-rhodamine 6G chemiluminescence.

Chemiluminescence (CL) of the rhodamine 6-G-diperiodatonickelate (IV) (Rh6-G-Ni(IV) complex) in the presence of Brij-35 was examined in an alkaline medium and implemented using flow-injection analysis to analyze Mn(II) in natural waters. Brij-35 was identified as the surfactant of choice that enhanced CL intensity by about 62% of the reaction. The calibration curves were linear in the range 1.7 × 10-3 - 0.2 (0.9990, n = 7) and 8.0 × 10-4 - 0.1 μg ml-1 (0.9990, n = 7) with limits of detection (LODs) (S:N = 3) of 5.0 × 10-4 and 2.4 × 10-4 μg ml-1 without and with using an in-line 8-hydroxyquinoline (8-HQ) resin mini-column, respectively. The sample throughput and relative standard deviation were 200 h-1 and 1.7-2.2% in the range studied respectively. Mn(II) concentrations in certified reference materials and natural water samples was successfully determined. A brief discussion about the possible CL reaction mechanism is also given. In addition, analysis of V(III), Cr(III) and Fe(II) was also performed without and with using an in-line 8-HQ column and selective elution of each metal ion was achieved by adjusting the pH of the sample carrier stream with aqueous HCl solution.

Micellisation behavior on the dodecyltrimethylammonium bromide in the presence of Brij-35 in pure water by conductivity measurement

Conductivity measurement of dodecyltrimethylammonium bromide in the presence of Brij-35 in aqueous media at 289.15 K is performed. The result showed a sharp increase in conductivity with increase in the concentration of dodecyltrimethylammonium bromide in the presence of Brij-35. The graph of specific conductivity versus concentration is used in determining the critical micelle concentration (CMC). There is the decrease in CMC of dodecyltrimethylammonium bromide in the presence of Brij-35 in comparison with the CMC of dodecyltrimethyl ammonium bromide [DTAB]. Gibbs free energy of micellisation has also been evaluated. BIBECHANA 15 (2018) 85-89

In situ investigation into surfactant effects on the clearance of polycyclic aromatic hydrocarbons adsorbed onto soybean leaf surfaces

The partitioning of polycyclic aromatic hydrocarbons (PAHs) in agricultural crop leaves, contributes to the exposure of organisms to these chemicals through the dietary pathway. To precisely predict the fate of PAHs and crop safety, the clearance of three-ringed phenanthrene (Phe) and four-ringed pyrene (Pyr) adsorbed individually onto living soybean leaf surfaces, as well as the effects of two surfactants, namely, an ionic surfactant (sodium dodecylbenzene sulfonate, SDBS) and a non-ionic surfactant (polyoxyethyleneglycol dodecyl ether, Brij35), were investigated in situ using the laser-induced nanosecond time-resolved fluorescence (LITRF) method. The effects varied significantly with surfactant types primarily in terms of the elimination rates and the final residues of PAH chemicals. With increasing SDBS and Brij35 concentrations, volatilization rate constants (kC) of both Phe and Pyr initially decreased at fast rates and then at more moderate rates later on, resulting from the plasticizing effect of surfactants adsorbed on leaf surfaces. In addition, the photolysis rate constants (kP) decreased with the presence of SDBS but increased with the presence of Brij35. Overall, the total clearance rates of PAHs (kT) adsorbed onto living soybean leaf surfaces were inhibited by the presence of SDBS but promoted by the presence of Brij35. These observations show that surfactants may significantly alter the clearance of PAHs in agricultural systems, and the potential impact of surfactants on crop safety is closely related to surfactant types in natural environments.

Effects of Two Surfactants and Beta-Cyclodextrin on Beta-Cypermethrin Degradation by Bacillus licheniformis B-1.

The biodegradation efficiency of beta-cypermethrin (β-CY) is low especially at high concentrations mainly due to poor contact between this hydrophobic pesticide and microbial cells. In this study, the effects of two biodegradable surfactants (Tween-80 and Brij-35) and β-cyclodextrin (β-CD) on the growth and cell surface hydrophobicity (CSH) of Bacillus licheniformis B-1 were studied. Furthermore, their effects on the solubility, biosorption, and degradation of β-CY were investigated. The results showed that Tween-80 could slightly promote the growth of the strain while Brij-35 and β-CD exhibited little effect on its growth. The CSH of strain B-1 and the solubility of β-CY were obviously changed by using Tween-80 and Brij-35. The surfactants and β-CD could enhance β-CY biosorption and degradation by the strain, and the highest degradation was obtained in the presence of Brij-35. When the surfactant or β-CD concentration was 2.4 g/L, the degradation rate of β-CY in Brij-35, Tween-80, and β-CD treatments was 89.4%, 50.5%, and 48.1%, respectively. The half-life of β-CY by using Brij-35 was shortened by 69.1 h. Beta-CY content in the soil with both strain B-1 and Brij-35 decreased from 22.29 mg/kg to 4.41 mg/kg after incubation for 22 d. This work can provide a promising approach for the efficient degradation of pyrethroid pesticides by microorganisms.

Sorption/desorption behavior of oxytetracycline and sulfachloropyridazine in the soil water surfactant system

Sorption/desorption of antibiotics, oxytetracycline (OTC), and sulfachloropyridazine (SCP) was investigated in the presence of a nonionic surfactant Brij35. Batch sorption experiments indicated that Freundlich equation fits sorption isotherms well for OTC. The sorption coefficients, KF, values were computed as 23.55 mL g(−1) in the absence of Brij35 and 25.46 mL g(−1) in the presence of Brij35 in the monomer form (below critical micelle concentration CMC, of 74 mg L(−1)). However, the KF values reduced to 12.76 mL g(−1) in the presence of Brij35 at 2.5 g L(−1). Therefore, irrigation with surfactant-rich water may increase the leaching potential of OTC. In the case of SCP, the KF value, in the absence of Brij35, was 19.95 mL g(−1). As a result of increasing the concentration of Brij35 to 0.25 g L(−1) (about 2.5 CMC), KF values first increased and reached a maximum value of 95.49 mL g(−1) and then reduced to 66.06 mL g(−1), at surfactant concentration of 5 g L(−1). Unlike OTC, the presence of surfactant in irrigation water is likely to decrease SCP leaching. In the case of OTC, hysteresis was found at Brij35 concentrations below CMC. However, OTC desorbed readily from soil (no hysteresis) at Brij35 concentrations above CMC. In the case of SCP, no hysteresis was found in the presence of the surfactant, both below and above CMC. Further, the obtained values of the efficiency coefficient (E), reveals that Brij35 had the potential to release more OTC from the soil (E > 1) as compared to SCP (E < 1). From these results, it can be concluded that regular use of manure on agricultural soils, especially in regions where poor quality irrigation water is used, can increase OTC contamination of water resources.

On-chip assay of matrix metalloproteinase-3 activity using fluorescence-conjugated gelatin arrays

We developed a new high-throughput approach to measure matrix metalloproteinase (MMP)-3 activity using Cy3-conjugated gelatin arrays. We fabricated Cy3-conjugated gelatin arrays by immobilizing Cy3-conjugated gelatin onto well-type amine arrays. The ratio of Cy3-NHS to gelatin was optimized to improve the efficiency of the arrays. MMP-3 activity was determined by the decrease of fluorescence intensity due to MMP-3-mediated degradation of Cy3-conjugated gelatin. The gelatinolytic activity of MMP-3 increased in the presence of Brij-35, a non-ionic detergent, in a dose-dependent manner. Cy3-conjugated gelatin arrays were successfully applied for the analyses of MMP-3 activity, which showed a dose-dependent degradation of the Cy3-conjugated substrate. This chip-based activity assay using a Cy3-conjugated gelatin array is simple, rapid, cost-effective, and has a potential for activity-based proteomic researches and screening of MMP-3 inhibitors.

Chemiluminescence Determination of Glucose, Fructose and their Mixture by the Stopped-Flow Mixing Technique

The chemiluminescence reaction of lucigenin with glucose and fructose in the presence of Brij-35 and in alkaline solution was used to develop kinetic methods for the determination of both hexoses individually and mixed together. A stopped-flow mixing module coupled to a photomultiplier tube allowed kinetic and equilibrium measurements, which were used for the individual determination of glucose and fructose. The same measurements were used to analyse the mixture of both sugars using a two equation system, which was resolved by multiple linear regression. The ranges of the calibration graphs obtained by using kinetic and equilibrium measurements were 25–1000 µg ml−1 and 75–1100 µg ml−1, respectively, for glucose and 1–350 µg ml−1 and 5–250 µg ml−1, respectively, for fructose. Mixtures of glucose and fructose in ratios between 1:0.4 and 40:1 were satisfactorily resolved.

Non-ionic micellar solubilization — spectrofluorimetric determination of trace of germanium(IV) with quercetin in real samples

A spectrofluorometric method is described for the determination of germanium(IV) based on its complexation reaction with quercetin in presence of Brij-35. The fluorescence is monitored at 552nm with excitation at 432nm. The pH, quercetin and Brij-35 concentrations were optimized simultaneously using the response surface methodology from sequential experimental three-variable Doehlert designs. Interferences in this determination have been studied. The detection limit is 7.4ngml−1 and the linear range is between 7.4 and 150ngml−1. The method has been applied to the determination of germanium in a drug and in wholemeal oats.

Photochemistry of Diflunisal in Nonionic (Brij-35) Micelles: Influence of the Microenvironment on Photoionization, Electron Trapping, and Persistent Radical Effect

The photochemistry of diflunisal (DF) in nonionic micelles of polyoxyethylene lauryl ether (Brij-35) has been investigated by combining steady-state and time-resolved spectroscopic techniques. Photophysical and photochemical measurements account for an efficient aggregation of the drug with the micellar system. Shortening of the singlet and lengthening of the triplet lifetimes of DF is observed upon incorporation into micelles, respectively. The former effect is responsible for changes in the relative weight of the mono- and biphotonic pathways of photoionization. The quenching constant related to the trapping by the ground state of DF of the hydrated electrons photoejected is markedly reduced in the presence of Brij-35. The exit dynamic of DF from the micellar cage is the almost exclusive rate-controlling step for the electron-trapping process. Both nature of the photoionization and efficiency of the electron trapping provide basic information about the localization of DF in the micellar cage. The “persi...

Kinetic spectrophotometric determination of traces of sulfide in nonionic micellar medium.

A sensitive kinetic spectrophotometric method for the determination of ng amounts of sulfide has been developed based on the reduction of Azure A by sulfide in the presence of Brij-35 at pH 7. The decrease in absorbance of Azure A at 600 nm is proportional to the concentration of sulfide over the range 25-1,400 ng mL(-1). The variables affecting the rate of the reaction were investigated and the optimum conditions were established. The method is simple, rapid, precise, sensitive, and widely applicable. The limit of detection is 17 ng mL(-1), and the relative standard deviation of seven determinations of 500 ng mL(-1) sulfide was 2.1%. The method was applied to the determination of sulfide in spring water.

Micelle Enhanced Spectrofluorimetric Determination of L-ascorbic Acid Based on Laccase-linked Coupling Reaction Using Flow-injection Stopped-flow Technique.

A novel spectrofluorimetric method for determination of L-ascorbic acid is described. It is based on the inhibition of L-ascorbic acid on the formation of 2, 3-diaminophenazine, which is an oxidation product of o-phenylenediamine catalyzed by laccase, in the presence of Brij-35, which shows strong enhancement on the fluorescence(at λem/λex=530nm/430nm) of the product, while no effect on the laccase-catalyzed reaction. The mechanism of o-phenylenediamine oxidation reaction catalyzed by laccase in the presence of L-ascorbic acid is discussed. L-ascorbic acid is determined in the range of O.02-2.Oμg/ml with a detection limit of 0.014μg/ml. The method is applied to the determination of L-ascorbic acid in pharmaceuticals, the results agree well with the nominal values and those obtained by the reference method.