A general chemiluminescence method for the determination of surfactants based on its quenching effect on the luminol-NaIO4-cyclodextrin reaction

Here we report that all types of surfactant could be simply and sensitively determined, by directly quenching the chemiluminescence (CL) between luminol and NaIO4 in a basic solution containing one polyhydroxyl compound such as cyclodextrin (CD), glucose or glycerol. This specific quenching effect was attributed to the change of the microenvironment of the CL reaction, caused by the addition of various surfactants. Based on this fact, the potential use of this CL reaction was exemplified by the cationic surfactant CTMAB, anionic surfactant SDS and non-ionic surfactant Triton X-100. It was found that the measurable range of CTMAB, SDS and Triton X-100 were 4.0 x 10(-6)-4.0 x 10(-4) M by using a basic CD-luminol-NaIO4 CL reaction. With our simple setup, CTMAB, SDS and Triton X-100 were detectable at a concentration as low as 2 microM. Overall, this new CL reaction is quite promising for the post-column determination of surfactant mixtures.     

Electrokinetic characterization of polystyrene–non-ionic surfactant complexes

An experimental study on the electrophoretic mobility (μ_e) of polystyrene particles after the adsorption of non-ionic surfactants with different chain lengths is described. Two sulphate latexes with relatively low surface charge densities (3.2 and 4.8 μC cm⁻²) were used as solid substrate for the adsorption of four non-ionic surfactants, Triton X-100, Triton X-165, Triton X-305 and Triton X-405, each one with 9–10, 16, 30 and 40 molecules of ethylene oxide (EO), respectively. The electrophoretic mobility of the polystyrene–non-ionic surfactant complexes was studied versus the amount of adsorbed surfactant (Γ). The presence of non-ionic surfactant onto particles surface seems to produce a slight shifting of the slipping plane because the mobilities of the different complexes display a very small decreasing. The increase in the number of EO chains in the surfactant molecule seems to operate as a steric impediment which decreases the number of adsorbed large surfactant molecules. The electrophoretic mobilities of the latex–surfactant complexes with maximum adsorption were measured versus the pH and ionic strength of the dispersion. While the different complexes showed a similar qualitative behaviour compared with that of the bare latex against the pH, the adsorption of the surfactant reduces the typical maximum in the μ_e−log[electrolyte].     

浊点萃取-分光光度法测定自来水及酒类样品中的痕量铁

利用非离子表面活性剂TritonX-100在温度高于其浊点时形成相分离行为,建立了浊点萃取-分光光度法测定痕量铁的新方法,探讨优化了以KSCN为显色剂,TritonX-100浊点萃取富集痕量铁的实验条件.研究发现:加入正辛醇可使TritonX-100的浊点降低约30℃,有利于萃取实验的进行;同时,加入的正辛醇与TritonX-100对痕量铁起到了协同萃取作用.在优化了的实验条件下,进行了痕量铁的分析,检出限为0.02mg·L-1,加标回收率为97.4%～101.6%,应用于自来水及酒类样品中痕量铁的测定,结果满意.     

An atomic absorption spectrometric method for the determination of non-ionic surfactants

A method is described for the determination of non-ionic surfactants in the concentration range 0.05–2 mg l^-1.Surfactant molecules are extracted into 1,2-dichlorobenzene as a neutral adduct with potassium tetrathiocyanatozincate(II) and the determination is completed by atomic absorption spectrometry. With a 150-ml water sample, the limit of detection is 0.03 mg l^-1(as Triton X-100).The method requires a single phase separation step, is applicable, without modification, to fresh, estuarine and sea-water samples and is relatively free from interference by anionic surfactants; the presence of up to 5 mg l^-1 of anionic surfactant (as LAS) introduces an error of no more than 0.07 mg l^-1 (as Triton X-100) in the apparent non-ionic surfactant concentration.     

Screening of urinary coproporphyrin using cloud point extraction and chemiluminescence detection

A simple screening test was developed for the sensitive and selective measurement of urinary coproporphyrin. In this screening test, efficient and selective extraction/pre-concentration of coproporphyrin from the aqueous medium(urine) into a much smaller volume phase containing a common non-ionic surfactant (Triton X-100) and ethyl acetate was accomplished by the addition of a relatively large amount of a cloud point depressing electrolyte (K(3)PO(4)) into the sample solution to effect cloud point separation. Sensitive and selective detection of coproporphyrin in the mixed Triton X-100 and ethyl acetate phase was performed via chemical excitation using the peroxyoxalate chemiluminescence reaction. The effects of surfactant and cations (from the cloud point depressing electrolyte) on the chemiluminescence intensity of coproporphyrin were briefly investigated. Furthermore, the spectrum of urinary coproporphyrin obtained using the present chemiluminescence method was briefly compared with that obtained from fluorescence method.     

Uranium micelle-mediated extraction in acetate medium: factorial design optimization

A micelle-mediated extraction (CPE) procedure has been developed to remove trace amounts of uranium from wastewater using a non-ionic surfactant (Triton (X-100)) and lipophilic chelating extracting agent (D2EHPA) in acetate medium. The methodology used is based on the formation of metal complexes soluble in a micellar phase of a non-ionic surfactant. The uranyl ions complexes are then extracted into the surfactant-rich phase at a ambient temperature. The effects of different operating parameters such as the concentrations of Triton (X-100), D2EHPA and metal ions, temperature, sodium acetate rate and pH on the cloud point extraction of uranyl ions were studied in details and a set of optimum conditions were obtained. The results showed, without contribution of energy (ambient temperature), that up to 1000?ppm of uranyl ions can quantitatively be removed (>97?%) in a single CPE extraction using optimum conditions.     

Surfactant-induced amorphous aggregation of tobacco mosaic virus coat protein: a physical methods approach

The interactions of non-ionic surfactant Triton X-100 and the coat protein of tobacco mosaic virus, which is an established model for both ordered and non-ordered protein aggregation, were studied using turbidimetry, differential scanning calorimetry, isothermal titration calorimetry, and dynamic light scattering. It was found that at the critical aggregation concentration (equal to critical micelle concentration) of 138 x 10(-6) M, Triton X-100 induces partial denaturation of tobacco mosaic virus coat protein molecules followed by protein amorphous aggregation. Protein aggregation has profound ionic strength dependence and proceeds due to hydrophobic sticking of surfactant-protein complexes (start aggregates) with initial radii of 46 nm. It has been suggested that the anionic surfactant sodium dodecyl sulfate forms mixed micelles with Triton X-100 and therefore reverses protein amorphous aggregation with release of protein molecules from the amorphous aggregates. A stoichiometric ratio of 5 was found for Triton X-100-sodium dodecyl sulfate interactions.     

Indirect spectrophotometric determination of cyanide by means of the colour reaction of silver with cadion 2B in presence of triton X-100

Silver gives a colour reaction with cadion 2B in the presence of the non-ionic surfactant Triton X-100, and the suppression of the colour by competitive complexation of the silver can be used for the spectrophotometric determination of cyanide. Cyanide in waste water can be separated by distillation from other ions that also interfere, and then determined.     

Salting-out surfactant extraction of porphyrins and metalloporphyrin from aqueous non-ionic surfactant solutions

A number of cloud point temperature-depressing electrolytes have been investigated for the separation of a non-ionic surfactant (Triton X-100) from aqueous solutions and the corresponding extraction of the organic solutes into the smaller volume surfactant-rich phase using the salting-out method. High extraction efficiencies and preconcentration factors were obtained at room temperature for the extraction of several hydrophilic and hydrophobic metal-free porphyrins (uroporphyrin, coproporphyrin, protoporphyrin and hematoporphyrin) and one metalloporphyrin (iron-protoporphyrin) that were dissolved in the aqueous non-ionic surfactant solutions. Possible mechanisms responsible for the efficient extraction of these important biological molecules into the surfactant-rich layer are discussed.     

Simultaneous cloud-point extraction of nine cations from water samples and their determination by flame atomic absorption spectrometry.

The cloud-point methodology was successfully employed for the preconcentration of heavy metal cations at trace levels from aqueous samples prior to flame atomic absorption spectrometry (FAAS). Cations were taken into a complex with 8-quinolinol in an aqueous non-ionic surfactant, Triton X-114, medium and concentrated in the surfactant rich phase by bringing the solution to the cloud-point temperature. The preconcentration of only 100 mL of the solution with 1% Triton X-114 and 10(-3) M 8-quinolinol at pH 7.0 gave a preconcentration factor higher than 100 for most cations. Under these conditions, the detection limits of the cloud-point extraction-FAAS system were 0.8 - 15 microg/L.     

The interaction of electrolytes with non-ionic surfactant micelles

The effect of NaCl and HCl on two non-ionic surfactant micelles was studied using several techniques, including conductivity and ion-selective electrodes. Both surfactants exhibit opposite behaviour. When Tween 20 is titrated with HCl the conductivity notably increases in comparison with water, whereas that of Triton X-100 solutions do not change with respect to water until a certain HCl concentration is reached, when it increases. The hydrogen ion activity is lower in Triton X-100 solutions and higher in Tween 20 solutions than in pure water. Chloride ion activity is higher in Tween 20 solutions than in water, whereas in Triton X-100 the activity does not significantly differ from that in water. The activity of sodium ion is lower in Tween 20 solutions than in water, whereas that in Triton X-100 solutions does not differ from the titration of water. These phenomena are explained by the changes in conformation of the non-ionic headgroups, which capture water, and in some cases ions, modifying the activity of ions in the intermicellar solution.     

Triton X-100-stabilized "oil-in-water" emulsions as suitable media for alkalimetric determination of hydrophobic organic acids

The protolytic properties of fat row carbonic acids in Triton X-100-stabilized "oil-in-water" (O/W) emulsions were studied. The differential influence of emulsions on the force of acids was shown to depend on the length of the hydrocarbon radical. The conditions for separate alkalimetric determinations of acids with different hydrophobicities in their mixtures using emulsions stabilized by non-ionic surfactant were suggested. The procedure for the determination of 4-chloro- N-(2-furilmethyl)-5-sulfamoylanthranilic acid (furosemide) main substance content in pharmaceuticals using Triton X-100-stabilized emulsion was proposed.     

Parameters Involved in the Sol-Gel Transition of Titania in Reverse Micelles

Titania nanoparticles and gels are synthesized in reverse micelles with either an ionic (AOT) or a non-ionic (Triton X-100) surfactant in alkanes with low water contents. Acids were in some cases dissolved in the aqueous phase. Whereas the size of the sol nanoparticles is independent of the micellar composition, the kinetics of the sol-gel transition are not. The gelation time is shorter for the non-ionic surfactant and becomes longer as the acid content in the water increases, and for smaller anions of equal charge.     

Electrochemical behavior of anthraquinone in aqueous solution in presence of a non-ionic surfactant

Cyclic voltammetric behavior of anthraquinone in aqueous medium has been studied in presence of a non-ionic surfactant, Triton X-100 (TX-100) using sodium salt of anthraquinone-2-sulphonic acid (AQS) as the electro-active species. When cathodic potential is applied, the anthraquinone (AQ) group of AQS is reduced to its dianion. In the reverse scan, the oxidation of AQ²⁻ gives AQ. The electrochemical behavior shows a profound influence from the dissolved state of TX-100 in aqueous media. Spectrophotometric results indicate interaction between AQ and TX-100. A CEC (chemical–electrochemical–chemical) mechanism with the electrochemical reaction coupled with preceding interaction of AQS with TX-100 and following protonation reaction of reduced AQ has been proposed.     

Enhanced electrochemiluminescence from Os(phen)2(dppene) (phen=1,10-phenanthroline and dppene=bis(diphenylphosphino)ethene) in the presence of Triton X-100 (polyethylene glycol tert-octylphenyl ether)

The effects of the non-ionic surfactant Triton X-100 (polyethylene glycol tert-octylphenyl ether) on the properties of Os(phen)₂(dppene)²⁺ (phen=1,10-phenanthroline and dppene=bis(diphenylphosphino)ethene) electrochemiluminescence (ECL) have been investigated. The anodic oxidation of Os(phen)₂(dppene)²⁺ produces ECL in the presence of tri-n-propylamine (TPrA) in aqueous surfactant solution. Increases in ECL efficiency (≥3-fold) and TPrA oxidation current (≥2.0-fold) have been observed in surfactant media with experiments supporting adsorption of surfactant on the electrode surface.     

Gamma-radiolysis of Triton X-100 aqueous solution

The decomposition of the non-ionic surfactant Triton X-100 in gamma-irradiated deaerated aqueous solution is mainly attributed to the attack of OH radicals and H atoms. The mechanisms of these reactions were investigated in detail, including the influence of pH and dose rate. The RCHOH radicals formed by OH attack on alcohol molecules can decompose the surfactant in aqueous solution.     

Chemiluminescence determination of surfactant Triton X-100 in environmental water with luminol-hydrogen peroxide system

Background  

The rapid, simple determination of surfactants in environmental samples is essential because of the extensive use and its potential as contaminants. We describe a simple, rapid chemiluminescence method for the direct determination of the non-ionic surfactant Triton X-100 (polyethylene glycol tert-octylphenyl ether) in environmental water samples. The optimized experimental conditions were selected, and the mechanism of the Luminol-H₂O₂-Triton X-100 chemiluminesence system was also studied.     

Kinetics of metribuzin degradation by colloidal manganese dioxide in absence and presence of surfactants

The kinetics of the degradation of metribuzin by water-soluble colloidal MnO₂ in acidic medium (HClO₄) were studied spectrophotometrically in the absence and presence of surfactants. The experiments were performed under pseudo-first-order reaction conditions in respect of MnO₂. The degradation was observed to be of the first order in respect of MnO₂ while of fractional order for both metribuzin and HClO₄. The rate constant for the degradation of metribuzin was observed to decrease as the concentration of MnO₂ increased. The anionic surfactant, sodium dodecyl sulphate (SDS), was observed to be ineffective whereas the non-ionic surfactant, Triton X-100 (TX-100), accelerated the reaction rate. However, the cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), caused flocculation with oppositely-charged colloidal MnO₂; hence further study was not possible. The catalytic effect of TX-100 was discussed in the light of the available mathematical model. The kinetic data were exploited to generate the various activation parameters for the oxidative degradation of metribuzin by colloidal MnO₂ in the absence as well as the presence of the non-ionic surfactant, TX-100.     

Spectroscopic investigations on the binding of ammonium salt of 8-anilino-1-naphthalene sulfonic acid with non-ionic surfactant micelles in aqueous media

The anionic dye 8-anilino-1-napthalensulfonic acid ammonium salt, or ANS, was used as a fluorescent probe to investigate the behaviour of dye-surfactant interactions in aqueous solutions of Triton X-100 and the Brij and polyoxyethylene tridecyl ether (POE TDE) series of polyoxyethylene non-ionic surfactants. The fluorescence behaviour of the dye with the non-ionic surfactants was examined in micellar media. The concentration of surfactant was kept well above the cmc to investigate the interaction of the dye with surfactant micelles. In this investigation, the relative fluorescence enhancements, binding constants of the dye to the surfactant micelles and aggregation numbers of the micelles were determined, from the analysis of spectroscopic data.     

发光金纳米粒子测定曲通X-100及其临界胶束浓度

参照文献方法合成了BSA保护的水溶性发光金纳米粒子, 并考察了此探针在非离子表面活性剂曲通X-100中的发光行为.根据观察到的发光增强效应, 建立了一种简单的测定曲通X-100的方法.考察了发光金纳米粒子的浓度、体系酸度、反应时间及共存物质对测定的影响.在最佳条件下, 发光强度与曲通X-100的浓度分别在0～150 μmol/L和150～600 μmol/L范围内分段成正比关系.两条工作曲线的交点所对应的浓度与曲通X-100的临界胶束浓度十分吻合, 为胶束形成过程提供了直接的指示.作为一种生物相容性探针, 发光金纳米粒子被用于生物学样品中曲通X-100的分析测定, 结果令人满意.