Triton X-100 Micellar Medium Research Articles

Electron beam mediated synthesis of photoluminescent organosilicon nanoparticles in TX-100 micellar medium and their prospective applications

The inherent advantages of Silicon have made it as one of the most sought-after elements in the field of nanoscience and nanotechnology. Herein, we report an electron-beam induced formation of blue light emitting organosilicon nanoparticles (OSiNPs) in the micellar medium of Triton X-100 (TX-100). The profound role of the micellar medium can be realized from the enhanced colloidal stability as well as photoluminescence (PL) quantum efficiency (from ~9% to ~55%) of as synthesized OSiNPs. Mechanistic investigations revealed the crucial role of hydroxyl radical (OH) in the formation of OSiNPs. XPS and FTIR studies indicated the presence of siloxane/silicone and silica (SiO2) like units as the major constituents in the NPs. XRD pattern showed the amorphous nature of the NPs, while TEM studies revealed their aggregation. The hydrodynamic size of the NPs was determined to be ~24 nm. Interestingly, the NPs exhibited an excitation-wavelength-dependent PL behaviour, thereby indicating the presence of multiple emission centres (ECs). Detailed investigations based on steady-state as well as time-resolved PL measurements were conducted to analyse these ECs. In addition, pH and temperature-dependent studies were carried out to further substantiate these findings. Moreover, the experimental observations revealed their potential applications in the areas of thermosensing, fingerprinting and cell-imaging. Notably, the internalization of as prepared NPs within cells was evident from the bright fluorescence images obtained from the cytoplasmic region as compared to control cells. This observation also suggests the prospective application of these NPs for image guided drug delivery systems.

Highly sensitive detection of Ceftriaxone in water, food, pharmaceutical and biological samples based on gold nanoparticles in aqueous and micellar media

A colorimetric assay with excellent sensitivity is reported to detect Ceftriaxone in aqueous and micellar solutions. Ceftriaxone could induce the aggregation of gold nanoparticles through hydrogen-bonding interaction and electrostatic attraction. As a result of aggregation, the surface plasmon resonance band around 520 nm decreases and a new band appears at 620 nm. The effect of surfactants was investigated on the aggregation. The band around 620 nm is shifted to around 685 nm in Triton X-100 micellar media and that is seen color conversion from red to deep blue which is clearly detectable by the naked eye. The results were improved in Triton X-100 micellar media as compared to aqueous media so that the lowest measured concentration and detection limit in micellar media have decreased 10 and 8 times, respectively. Triton X-100 showed strong effect on the stabilization of the solutions. The method has been successfully applied for the analysis of various real samples.

SPECTROPHOTOMETRIC DETERMINATION OF TITANIUM (IV) IN STEEL, PAINT AND A COSMETIC CREAM USING TANNIC ACID IN MICELLAR MEDIUM

A highly simple, rapid and sensitive spectrophotometric procedure is described for micro-amounts determination of titanium (IV) using tannic acid (tannin) as a new reagent in presence of Triton X-100 (micellar medium). Titanium (IV) reacted with tannic acid in slightly acidic medium at pH=6 using citrate buffer solution to form a 1:2 red coloured stable complex with maximum absorption at 436 nm. The complex is instantaneously formed and remain stable over 2 hr. Beer's law is obeyed in the range of 2-26 μg Ti ml-1 with molar absorptivity to be 3.66 × 104 L mol-1 cm-1. The proposed method is successfully applied for titanium determination in steel, paint and pharmaceutical samples.

Assessment of the antioxidant properties of micellar spice extracts by galvanostatic coulometry with electrogenerated hexacyanoferrate(III) ions

The stoichiometric coefficients of reactions of individual antioxidants of spices—rutin; quercetin; eugenol; curcumin; capsaicin; thymol; tannin; catechol; and gallic, p-coumaric, caffeic, chlorogenic, and rosmarinic acids—with electrogenerated hexacyanoferrate(III) ions in a Triton X100 micellar medium are determined; the corresponding reaction schemes are proposed. It is found that the maximum recovery of active components from spices is achieved at a single extraction with a 0.25 mM Triton X100 solution for 10 min upon sonication. The raw material: extractant ratio is 1: 30 for all spices except for caraway, red sweet pepper, and nutmeg (1: 40) and cumin and red pepper (1: 20). The ferric reducing power (FRP) of micellar extracts of 16 spices is evaluated. It is found that the highest FRP is characteristic for cinnamon and clove (122 ± 4 and 106 ± 6 C/g, respectively), while the lowest value of this parameter is typical for cumin and turmeric (3.3 ± 0.3 and 2.5 ± 0.3 C/g, respectively), which is because of the nature of the active components of spices and the extractant. The FRP of spices correlates with their antiradical activity and the total phenolic content with r = 0.9714 and 0.9936, respectively.

Voltammetric sensing and quantification of eugenol using nonionic surfactant self-organized media

Triton X100 and Brij® 35 based self-organized systems (at a concentration of 0.1 M) provide eugenol solubilization in water media. Eugenol is irreversibly oxidized on a glassy carbon electrode at 780 and 700 mV in 0.1 M LiClO4 in 0.1 M Triton X100 and Brij® 35 micellar media, respectively. Electrochemical oxidation of eugenol is a diffusion-controlled process that is confirmed by the linear dependence of peak currents on the v1/2 with R2 = 0.9968 and 0.9989 in Triton X100 and Brij® 35 media, respectively, and involves 2.0 ± 0.1 electrons corresponding to the formation of o-quinone. The eugenol calibration graph is linear in the range 15–1230 μM with an estimated detection limit of 3.8 μM and a quantification limit of 12.6 μM. The addition of ethanol (10% v/v) to a 0.1 M Triton X100 micellar medium leads to the cathodic shift of eugenol oxidation potential of 50 mV. Under these conditions, the oxidation current linearly depends on the eugenol concentration in the range 0.02–1.0 mM with a detection limit of 0.01 mM. The recovery of eugenol determination in test solutions is in the range 99.0–101.2%. The preliminary extraction of eugenol with ethanol is used for its voltammetric determination in spices. Quantitative determination of eugenol in essential oils in a Triton X100 micellar medium has been carried out. The results obtained for real samples are in good agreement with data from independent spectrophotometric methods.

Simultaneous spectrophotometric determination of Cu(II), Co(II) and Ni(II) using ratio spectra-continuous wavelet transformation in some food and environmental samples

Ratio spectra-continuous wavelet transformation was used for the simultaneous determination of ternary mixtures of copper, cobalt and nickel without prior separation steps. The method is based on the complexation reaction of these cations with 1-(2-pyridylazo)-2-naphthol (PAN) in triton X-100 micellar media at pH 8.0. The results showed that Cu(II), Co(II) and Ni(II) could be determined simultaneously in the ranges 0.20-4.0, 0.20-4.0 and 0.50-7.0 mg L-1, respectively. Different mother wavelets from the family of continuous wavelet transforms were selected and applied under the optimal conditions for multi-component determinations. The method was tested by analyzing various synthetic ternary mixtures of Cu(II), Co(II) and Ni(II) ions. Under the working conditions, the proposed method was successfully applied for the simultaneous determination of these metals content evaluation in some real samples including multivitamin tablet, tea, barley, spinach, chocolate, milk powder, soil, sea water and tap water samples.

Chemometrics-assisted spectrophotometric methods for simultaneous determination and complexation study of Fe(III), Al(III) and V(V) with morin in micellar media

Evolutionary factor analysis (EFA) and rank annihilation factor analysis (RAFA) were applied to resolve the two-way equilibrium spectrophotometric data belonging to the complexes of Fe(III), Al(III) and V(V) with morin (3,5,7,20,40-penta hydroxy flavone) as chelating agent in triton X-100 micellar media. Then, partial least square regression combined with genetic algorithm for wavelength selection (GA-PLS) was used for simultaneous determination of the metal ions. The parameters controlling behavior of the system were investigated and optimum conditions were selected. The predictive abilities of partial least squares regression (PLS) and genetic algorithm-partial least squares regression (GA-PLS) were examined in simultaneous determination of ternary mixtures of metal ions over the concentration range of 17.0–170.0 ng ml −1, 25.0–180.0 ng ml −1 and 40.0–325.0 ng ml −1 for Fe(III), Al(III) and V(V), respectively. The relative standard errors for prediction of the ions in synthetic mixtures were lower than 5% and the mean recoveries in the tap water spiked samples were 104.2 and 101.7% for PLS and GA-PLS, respectively.

Kinetic spectrophotometric determination of Fe(II) in the presence of Fe(III) by H-point standard addition method in mixed micellar medium

The H-point standard addition method was applied to kinetic data for simultaneous determination of Fe(II) and Fe(III) or selective determination of Fe(II) in the presence of Fe(III). The method is based on the difference in the rate of complex formation between iron in two different oxidation states and methylthymol blue (MTB) at pH 3.5 in mixed cetyltrimethylammonium bromide (CTAB) and Triton X-100 micellar medium. Fe(II) can be determined in the range 0.25–2.5 μg ml −1 with satisfactory accuracy and precision in the presence of excess Fe(III) and other metal ions that rapidly form complexes with MTB under working condition. The proposed method was successfully applied to the simultaneous determination of Fe(II) and Fe(III) or selective determination of Fe(II) in the presence of Fe(III) in spiked real environmental and synthetic samples with complex composition.

Fluorescence enhancement and cofluorescence in complexes of terbium(III) with trimellitic acid

The fluorescence of terbium (III) was enhanced by about three orders of magnitude in the presence of trimellitic acid (benzene-1, 2, 4-tricarboxylic acid (TLA)) in aqueous solution at pH 6. The fluorescence intensity could be greatly increased when the system of Tb 3+-TLA was treated with La 3+(or Gd 3+) and TritonX-100. The addition of La 3+(or Gd 3+) enhances the fluorescence of the system by about two orders of magnitude due to cofluorescence, and the TritonX-100 micellar medium plays an important role for stabilization of the system. Both the intermolecular energy transfer mode and intramolecular energy transfer mode are responsible for the mechanism of fluorescence enhancement. In the optimum conditions, the fluorescence intensity is a linear function of Tb 3+ concentration in the range of 7.8 × 10 −9-3.6 × 10 −6 mol/L for the system Tb 3+-La 3+-TLA and 1.0 × 10 −8-4.7 × 10 −6 mol/L for the system Tb 3+-Gd 3+-TLA, and the limits of detection are 4.6 × 10 −10 mol/L and 6.0 × 10 −10 mol/L, respectively.

Highly Selective and Simple Zero and First Order Derivative Spectrophotometric Determination of Palladium by Using α-Benzilmonoxime in Triton X-100 Micellar Solution

The reaction of <TEX>${\alpha}$</TEX>-Benzilmonoxime with palladium(II) produces a green complex in triton X-100 micellar media. Palladium has been determined using zero and first derivative spectrophotometric methods. The absorbances of Pd(II)- <TEX>${\alpha}$</TEX>--benzilmonoxime complex at 441.8 and 677.0 nm in 0.10 M perchloric acid solution were monitored and linear working ranges of 0.3-12.0 and 0.7-20 <TEX>${\mu}$</TEX>g mL<TEX>$^{-1}$</TEX> with detection limits of 0.07 and 0.10 <TEX>${\mu}$</TEX>g <TEX>$mL^-1$</TEX> were obtained, respectively. Also, recoveries in the range of 92.8 to 100.1% and relative standard deviations in the range of 0.4 to 7.1% were obtained. First derivative spectrophotometry has also been applied for palladium determination under the optimum condition. The linear dynamic range of 0.2-24.0 <TEX>${\mu}$</TEX>g <TEX>$mL^{-1}$</TEX> palladium with relative standard deviations of 0.6-6.9% and recoveries in the range of 94.9-102.5% has been obtained by first derivative spectrophotometry. The method shows high selectivity because of the high concentration of acid used, which prevents formation of complexes of <TEX>${\alpha}$</TEX>--benzilmonoxime with the other cations. The palladium complex formed was stable at least one day. The method was successfully applied to the determination of palladium in some synthetic palladium alloys and palladium-charcoal powder.

Fluorimetric estimation of DNA content using sensitized lanthanide fluorescence

Lanthanide fluorescence enhancement on complexation with calf thymus DNA was studied in aqueous solution. The DNA sensitized and enhanced fluorescence of terbium and europium by nearly two orders of magnitude. By applying this ligand sensitized lanthanide fluorescence enhancement, DNA could be estimated at 10 ppb level. Further, effect of addition of TOPO in Triton X-100 micellar medium to Tb–DNA complex in solution was also studied. On addition of TOPO, no synergistic terbium fluorescence enhancement was observed.

Catalytic Kinetic Spectrophotometric Determination of Trace Amounts of Silver in Triton X-100 Micellar Medium

A catalytic method has been developed for the determination of trace amounts of Ag+ in Triton X-100 micellar medium. The method is based on the catalytic effect of silver(I) on the rate of a ligand substitution reaction between potassium ferrocyanide and 4,7-biphenyl-1,10-phenanthroline (BPT). The reaction was followed spectrophotometrically at 536 nm by measuring the induction period. Beer's law was obeyed in the range of 0–0.040 µg/mL Ag+ and the apparent molar absorptivity was 2.43 × 106 L mol−1 cm−1. Both the influence of reaction variables and the interference of coexistent ions were studied. The proposed method has been applied to the wastewater samples with satisfactory results. The recoveries were between 93.2 and 107% and the RSD was below 4.0%.

Simultaneous Spectrophotometric Determination of Iron, Titanium, and Aluminum by Partial Least-Squares Calibration Method in Micellar Medium

Simultaneous spectrophotometric determination of iron, titanium and aluminum was carried out using their morin (3,5,7,2′,4′-penta hydroxy flavone) complexes in Triton X-100 micellar medium. Partial least-squares regression was employed for the resolution of ternary mixtures of Fe, Ti, and Al. The presence of Triton X-100 micellar system avoids the solvent extraction step necessary for the formation of soluble morin complexes. The limits of detection obtained for Fe (III), Ti (IV), and for Al (III) were 0.03, 0.04, and 0.02 µg mL−1, respectively. The relative standard error for applying the method to the analysis of 20 synthetic samples in the concentration ranges of 0.03 to 1.0 µg mL−1 Al (III), 0.06 to 1.6 µg mL−1 Ti (IV), and 0.04 to 1.5 µg mL−1 Fe (III) was 5%. Analysis of synthetic and artificial mixtures of solutions of several alloys was successfully performed by the method.

A fluorimetric study of terbium, europium and dysprosium in aqueous solution using pyridine carboxylic acids as ligands

Fluorescence enhancement of Tb 3+, Eu 3+ and Dy 3+ was studied in aqueous solution using pyridine carboxylic acids (nicotinic, picolinic and dipicolinic acids) as ligands. The fluorescence intensity of Tb 3+, Eu 3+ and Dy 3+ could be enhanced, contrary to an earlier report by more than two to three orders of magnitude using these acids as ligands. To further enhance the lanthanide fluorescence, a neutral ligand, trioctyl phosphine oxide (TOPO), in Triton X-100 micellar medium was added to lanthanide–pyridine carboxylic acid complexes. However, the additional fluorescence enhancement of lanthanides, following the addition of TOPO was observed only with nicotinic acid.

Synergistic fluorescence enhancement of Tb with aromatic monocarboxylic acids and TOPO–Triton X-100: role of Triton X-100 in synergism

Fluorescence enhancement of Tb 3+ has been studied, using substituted benzoic acids as ligands. These ligands enhance the fluorescence of Tb 3+ by about three orders of magnitude. The enhancement is observed due to ligand sensitized fluorescence. The fluorescence of Tb 3+ in these complexes is synergistically enhanced by the addition of trioctylphosphine oxide (TOPO) in Triton X-100. The synergism displayed by TOPO was observed only when Triton X-100 micellar medium was used. TOPO dissolved in SDS/DTAB micellar medium did not result in synergistic fluorescence enhancement of Tb 3+. These observations are discussed in detail and the synergism displayed by TOPO is rationalized on the basis of the structure of the surfactants.

Determination of triphenyltin in sea-water by excitation–emission matrix fluorescence and multivariate curve resolution

A new method for the determination of triphenyltin (TPhT) in sea-water is proposed. The method is based on solid-phase extraction (SPE), reaction with flavonol in a Triton X-100 micellar medium to yield a fluorimetrically active derivative and excitation–emission fluorescence measurements. TPhT was quantified by an alternating least squares (ALS)-multivariate curve resolution (MCR) procedure and a single synthetic standard. In order to select the optimum conditions for the analysis, the procedure was assessed using synthetic samples. With the proposed method, TPhT was quantified in sea-water samples at low ng l −1 level with an overall prediction error of around 12%.

Spectral analysis of the aggregates of Stains-all in the presence of non-ionic surfactant Triton X-100 by principal component analysis method

Principal Component Analysis (PCA) method has been applied to determine the compositions of concentration induced metachromatic species of the cyanine dye Stains-all (Stal) in aqueous triton X-100 micellar medium. In different environments Stal shows a number of blue shifted peaks such as at 575, 535, 510, 470 nm etc. Among them we have been able to identify without any ambiguity the peaks at 575, 535 and 510 nm that have been assigned to the monomer, dimer and trimer of the dye. The molar absorption coefficient spectra of the individual species have also been determined. The equilibrium constant between monomer, dimer and trimer has also been calculated and found to be 7.17.

The surfactant concentration-dependent behaviour of safranine T in Tween (20, 40, 60, 80) and Triton X-100 micellar media

The visible and fluorescence spectra of the dye safranine T were studied in micellar solutions of non-ionic surfactants in different concentration ranges. The complexing strengths (1 : 1 dye : micelle charge transfer complex formed between the dye and micelle) of the non-ionic micelles increase with increasing concentration of the surfactant in the micellar solution. The aggregation number and several solvent parameterss, i.e. the Kosower z value, intramolecular charge transfer energy E T 30, dielectric constant of the micellar medium and viscosity of the micellar solution, were evaluated. These values remain constant over certain concentration ranges, but vary in different concentration regions of a surfactant.

Application of Partial Least Squares Multivariate Calibration to Triphenyltin Determination in Sea-water With Excitation–Emission Matrix Fluorescence

A partial least squares multivariate calibration approach, based on solid-phase extraction and excitation–emission matrix fluorescence using flavonol as fluorogenic reagent in a Triton X-100 micellar medium, is proposed for the determination of triphenyltin (TPhT) in sea-water. The calibration model is built from sea-water samples of known TPhT concentrations, and requires four factors for prediction. The method, which has a precision of 0.4% and a detection limit of 0.56 ng l–1, was shown to be suitable for TPhT monitoring in sea-water.

A Photochemical Study of Uranyl Ion Interaction with the Triton X-100 Micellar System

This is a report on the spectroscopic characteristics of UO2+2in the excited state in Triton X-100 micellar medium. It also indicates some important results of viscosity and surface tension measurements of the system which have direct relevance to the spectroscopic investigation in the excited state. The quenching of the UO2+2fluorescence due to Triton X-100, upon micellization in the aqueous medium, reveals two kinds of microenvironments of the fluorophore from the Stern–Volmer plot. This has been verified by flash photolytic measurements. A blue shift of the quenched emission spectrum is ascribed to the collisional encounter of UO2+2with the head groups of Triton X-100.