Spectrophotometric study of the reactions of bromopyrogallol red with cationogenic tensides: Determination of antimony

The effect of cationogenic tensides on the absorption spectra and apparent dissociation constants of bromopyrogallol red was studied. The pK values for the individual dissociation steps in the presence of Septonex indicate that the presence of cationogenic tenside increases the dissociation of all forms of this dye, which is of practical importance in the formation of complexes with many metals.Spectrophotometric study of the reaction of antimony(III) with bromopyrogallol red in the presence of cetylpyridinium bromide formed a basis for development of a new method for the spectrophotometric determination of antimony(III) in the range 0.40-3.60 μg Sb · ml^?1.     

Cetylpyridinium bromide-based oil-in-water microemulsions as a medium for hydrolysis of esters of phosphorus acids in the presence of primary amines

High-resolution ¹H NMR technique with Fourier-transform and pulsed-gradient spin-echo was used to study the structure of oil-in-water microemulsions based on cetylpyridinium bromide. The sizes of microdrops and the distribution of components between the disperse and continuous phases were found. It was shown for the hydrolytic decomposition of O,O-bis-(p-nitrophenyl) methyl phosphonate in the presence of amines that the microemulsion medium can affect both the rate and mechanism of hydrolysis. The reaction rate constants depend on the structure of microdrops.     

Resonance Rayleigh scattering for the determination of cationic surfactants with Eosin Y

Resonance Rayleigh scattering (RRS) of cationic surfactants–Eosin Y systems and their analytical application have been studied. In aqueous solution at pH 2～3, Eosin Y reacts with a monomer of cationic surfactants (CS), such as Zephiramine (Zeph), tetradecylpyridinium bromide (TPB), cetylpyridinium bromide (CPB), cetylpyridinium chloride (CPC) and cetyltrimethylammonium bromide (CTMAB), to form an ion associate and a new RRS spectrum appears. The spectral characteristics of the five ion associates are similar and their maximum scattering wavelengths (λ_max) are all at 313 nm. The intensity of RRS at λ_max of the ion associate is directly proportional to the concentration of CS in the range of 0～3.0 μg/25 mL. The technique has high sensitivity for the determination of CS; their detection limit is between 5.57 ng/mL and 7.60 ng/mL depending on the CS. In this case, most metal and non-metal ions, NH₄ ⁺ and some anionic surfactants do not interfere, so that the method has a good selectivity. It can be applied to the determination of trace amounts of cationic surfactants in water samples.     

Spectrophotometric determination of traces of lead with bromopyrogallol red and cetyltrimethylammonium or cetylpyridinium bromide

A method is described based on the sensitizing effect of cetyltrimethylammonium or cetylpyridinium bromide on the lead-Bromopyrogallol Red colour reaction. The reaction is instantaneous and the colour remains stable for over 120 hr in the presence of Triton X-100. Both colour systems obey Beer's law up to 5.5 ppm of lead. Methods are described for dealing with interferences.     

1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯的合成及与阳离子表面活性剂的显色反应

报道了1-（5-萘酚-7-磺酸）-3-[4-（苯基偶氮）苯基]-三氮烯（NASAPAPT）的合成，研究了该试剂与阳离子表面活性剂溴化十二烷基二甲基苄铵（DDMBAB），溴化十六烷基三甲铵（CTMAB）、溴化十六烷基吡啶（CPB）、溴化十四烷基吡啶（TPB）显色反应的条件。测定了显色反应的灵敏度，符合比尔定律的范围。建立了光度法测定微量阳离子表面活性剂的新方法。     

Synthesis,characterization, and insecticidal activity of new tin (IV) complexes

A three-component reaction of dimethyltin dibromide with imidazo[1,2-a]pyridine, pyridine derivatives, or isoquinoline and allyl bromide in refluxing ethanol affords the ionic complex, bis(1-allylcycloiminium) dimethyltetrabromostannate (II). The reaction involves N-allylation of cycloimine accompanied by the coordination of two bromide ions with the tin atom of dimethyltin dibromide. The complexes have been characterized by infrared and ¹H NMR, ¹³C NMR, and ¹¹⁹Sn NMR studies. The X-ray crystal structure analysis of a complex reveals the tin atom to be hexacoordinated and the dimethyltetrabromostannate (II) anion having octahedral geometry. Some of the complexes tested for their insecticidal activity are found to exhibit strong activity against Tribolium castaneum insect with LC₅₀ ranging from 0.4 to 0.8 ppm.     

用四(4-三甲铵苯基)卟啉作显色剂导数分光光度法同时测定钴镉铅的研究

本文以四(4-三甲铵苯基)卟啉作显色剂,在阳离子表面活性剂CPB存在下的pH9.8缓冲溶液中,利用三阶导数分光光度法,对钴、镉、铅的同时测定进行了详细研究。本方法测定灵敏度较高,对合成样品进行测定,结果令人满意。     

Mixing Behavior of Conventional and Gemini Cationic Surfactants

Micellization behavior of cationic monomeric surfactants, hexadecyltrimethylammonium bromide (CTAB), cetylpyridinium bromide (CPB), cetylpyridinium chloride (CPC), tetradecyltrimethylammonium bromide (TTAB), and dimeric (gemini) cationic surfactant pentamethylene‐1, 5‐bis(hexadecyldimethylammonium bromide) with formula C₁₆H₃₃(CH₃)₂N⁺(CH₂)₅N⁺(CH₃)₂C₁₆H₃₃ · 2Br^?, abbreviated as 16‐5‐16, in mixed states (binary) have been studied by conductivity. The micellar compositions, activities of the components, and their mutual interactions have been estimated from Rubingh's theory. The mixtures show nonideal behavior with favorable interactions.     

Resonance Rayleigh scattering for the determination of cationic surfactants with Eosin Y

Resonance Rayleigh scattering (RRS) of cationic surfactants–Eosin Y systems and their analytical application have been studied. In aqueous solution at pH 2∼3, Eosin Y reacts with a monomer of cationic surfactants (CS), such as Zephiramine (Zeph), tetradecylpyridinium bromide (TPB), cetylpyridinium bromide (CPB), cetylpyridinium chloride (CPC) and cetyltrimethylammonium bromide (CTMAB), to form an ion associate and a new RRS spectrum appears. The spectral characteristics of the five ion associates are similar and their maximum scattering wavelengths (λ_max) are all at 313 nm. The intensity of RRS at λ_max of the ion associate is directly proportional to the concentration of CS in the range of 0∼3.0 μg/25 mL. The technique has high sensitivity for the determination of CS; their detection limit is between 5.57 ng/mL and 7.60 ng/mL depending on the CS. In this case, most metal and non-metal ions, NH₄ ⁺ and some anionic surfactants do not interfere, so that the method has a good selectivity. It can be applied to the determination of trace amounts of cationic surfactants in water samples. Received: 9 September 1998 / Revised: 17 November 1998 / Accepted: 18 November 1998     

The extraction behaviour of the Rose Bengal labelled with131I in the presence of cationic surfactants

The Rose Bengal forms with cationic surfactants /1-carbethoxypentadecyltrimethyl-ammonium bromide, cetyltrimethylammonium bromide and cetylpyridinium bromide/ the extractable ion associates with composition 11 or 12. The extraction constants of the ion associates of the Rose Bengal with cationic surfactants were determined radiometrically with the aid of Rose Bengal labelled with¹³¹I.     

The Use of the Bismuth Film Electrode for the Anodic Stripping Voltammetric Determination of Tin

Bismuth coated glassy carbon electrodes have been applied to the square‐wave anodic stripping voltammetry (SWASV) of trace concentrations of tin. Optimization of Bismuth Film Electrode (BFE) performance was conducted after initial comparison with the more traditional mercury electrode. Simultaneous deposition of tin and bismuth at ?1.3 V for 2 minutes in a supporting electrolyte of 2.5 M sodium bromide utilizing a square‐wave stripping step, allowed analysis of tin at the μg L^?1 level. Parameters, such as deposition potential and time, bismuth concentration, square‐waveform settings including amplitude, step height and frequency were studied and optimized. The dependence of stripping current on deposition time indicates that using longer deposition time should facilitate sub μg L^?1 analysis. Tin was analyzed simultaneously with cadmium and either indium or thallium; Where as lead and copper were not resolved from the stripping peaks of tin and bismuth respectively. Finally, the method was applied to the analysis of tin in fruit juice.     

Spectrophotometric determination of tin(IV) by extraction of the ternary tin/iodide/5,7-dichloro-8-quinolinol complex

The characteristics of the ternary complexes formed by fluoride, bromide, iodide and thiocyanate with tin(IV) and 5,7-dichloro-8-quinolinol (HCQ) have been studied. A spectrophotometric method is proposed for the determination of tin(IV) (1–20 μg ml^?1), based on the extraction into chloroform of the tin/iodide/HCQ complex. Aluminium, bismuth and lead do not interfere, but antimony, copper, iron(III) and fluoride do. Copper and iron can be eliminated by preliminary extraction in the absence of iodide.     

Comparative study of the cationic surfactants and their influence on the alkaline hydrolysis of acetylsalicylic acid

A kinetic study of the reaction of acetylsalicylic acid (aspirin) with sodium hydroxide has been studied in the presence of some conventional and novel cationic surfactants. The pseudo‐first‐order rate constant increases with the surfactant concentration initially and then decreases. In comparison to conventional cationic surfactants, i.e., cetyltrimethylammonium bromide and cetylpyridinium bromide, novel alkyldiethylethanolammonium bromide (R = C₁₆) surfactant accelerated the alkaline hydrolysis significantly. The pseudophase ion‐exchange model has been applied to fit the experimental results. Activation parameters have also been evaluated. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 43: 1–8, 2011     

Spectrophtometric Determination of the Platinum Metals. Determination of Palladium with Eriochromcyanine R in the Presence of Cetylfyridinium Bromide

Abstract

A new photometric method has been developed for the determination of microgram amounts of id(II) on the basis of a ternary complex of the metal, eriochromcyanine R and cetylpyridinium bromide, which is formed in an acetate buffer medium (pH = 3.5 ? 5.5) and exhibits an absorption maximum at 630 nm. The system obeys the Lambert-Bear law for 0.2 ? 2.7 ppm Pd (II). The mean relative standard deviation is 0.14%, the molar absorbitivity is 6.5×10⁴ at the wavelength of the maximum difference between the absorbances of the sample and the blank, 630 nm, and the detection limit is 1.2×10^?3 μg cm^?2 for A = 0.001.     

Spectrophotometric determination of cationic surfactants by formation of ternary complexes with Fe(III) and chrome azurol

An extraction-free spectrophotometric method for the determination of cationic surfactants, such as cetylpyridinium chloride, cetyltrimethylammonium bromide and zephiramine is proposed, which is based on the formation of ternary complexes with Fe(III) and chrome azurol S. The molar ratio of the complex is 2:1:1 (Fe(III):chrome azurol S: cationic surfactant). The method is simple, rapid and sensitive, giving an apparent molar absorptivity of 4.5×10⁴ L·mol^?1-cm^?1 and a linear range of 0.1–6.0 μmol/L cationic surfactants. The total cationic surfactant content can be determined directly in aqueous solutions by measuring the absorbance at 680 nm (pH 5.8). The method has been successfully applied to water samples.     

亮绿褪色反应用于微量季铵盐型阳离子表面活性剂的分光光度法测定研究

在 p H 7.0 0 Tris- HCl缓冲介质中 ,微量季铵盐型阳离子表面活性剂溴化十六烷基三甲胺 ( CTMAB)和溴化十六烷基吡啶 ( CPB)能使亮绿 ( Brilliant Green,简称 BG)产生灵敏的褪色反应 ,发现其褪色程度ΔA (ΔA =A0 - Ai)与 CTMAB及 CPB用量存在定量关系。研究了该褪色反应的最佳条件 ,探讨了反应机理 ,拟定了利用该反应用于微量 CTMAB和 CPB的测定方法 ,CTMAB和 CPB的浓度分别在0～ 6× 1 0 - 5mol/ L ,0～ 8× 1 0 - 5mol/ L范围内符合比耳定律。拟定的方法用于电镀废液样品中微量 CTMAB的测定 ,结果满意     

Carbon Nanotube Based Sensor for Simultaneous Determination of Acetaminophen and Ascorbic Acid Exploiting Multiple Response Optimization and Measures in the Presence of Surfactant

A simple procedure for the simultaneous determination of acetaminophen (AC) and ascorbic acid (AA) by differential pulse voltammetry (DPV) using a carbon nanotube paste electrode exploiting measures in cetylpyridinium bromide (CPB) medium is described. Under the best instrumental parameters of DPV, optimized by means of factorial design, the calibration plots in the range 100.0–700.0 µmol L^?1 (r=0.993) and 39.4–146.3 µmol L^?1 (r=0.995) with limits of detection of 7.1 and 2.1 µmol L^?1, were achieved for AA and AC, respectively. The developed method was successfully applied for the AC and AA determination in pharmaceutical formulations, whose accuracy was attested by comparison with HPLC method.     

Feasibility of a Nano‐Carbon Black Paste Electrode for Simultaneous Voltammetric Determination of Antioxidants in Food Samples and Biodiesel in the Presence of Surfactant

In this work, a simple and low‐cost method was developed for the simultaneous determination of the antioxidants tert‐butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) in the presence of the cationic surfactant CPB by square wave voltammetry (SWV) technique using a carbon black paste electrode (CBPE). The performance of the method was investigated by varying parameters such as pH, electrolyte, and type and concentration of surfactant. Under the optimum conditions of 0.2 mol L^?1 phosphate buffer (pH 7.0), 600.0 μmol L^?1 of cetylpyridinium bromide surfactant and SWV operating parameters optimized through the Doehlert matrix, the method presented low limits of quantification for TBHQ and BHA (0.23 and 0.26 μmol L^?1, respectively) and high precision in successive measurements. The proposed method was applied in mayonnaise, margarine and biodiesel and the accuracy of method was checked by the HPLC technique.     

SiO(x) Monolayer Overcoating Effect on the TiO(2) Photocatalytic Oxidation of Cetylpyridinium Bromide

The effect of SiO(x) monolayer coverage on the rate of TiO(2) photocatalytic oxidation of cetylpyridinium bromide (CPB) in aqueous solutions has been studied. The rate of CPB removal from the solution (5相似文献   

Silica-modified magnetic nanoparticles functionalized with cetylpyridinium bromide for the preconcentration of metals after complexation with 8-hydroxyquinoline

Magnetically driven separation technology has received considerable attention in recent decade for its great potential application. In this study, we investigate the application of silica-modified magnetite nanoparticles (NPs) coated with a cationic surfactant as adsorbent for microextraction and determination of trace amounts of Cu(II), Ni(II), Co(II), Cd(II), Pb(II) and Mn(II) from environmental water samples. The synthesized silica-coated NPs in combination with cetylpyridinium bromide have the ability to adsolubilize the metal ions after complexation with 8-hydroxyquinoline. The NPs bearing the target metals are easily separated from the aqueous solution by applying an external magnetic field and the complexed metals were desorbed using acidic methanol. The desorbed analytes are introduced into the graphite furnace of an atomic absorption spectrometer. The effect of pH, complexing agent, amount of cetylpyridinium bromide, microextraction time, desorption conditions, ionic strength on extraction efficiency of the metal ions are investigated and optimized. Under the optimized conditions, the detection limits for Cu(II), Ni(II), Co(II), Cd(II), Pb(II) and Mn(II) are 4.7, 9.1, 9.5, 2.3, 7.4 and 15.3 ng L⁻¹, respectively and the relative standard deviations (n = 6) are less than 3.6%. The accuracy of the method was evaluated by recovery measurements on the spiked samples and good recoveries (93-113%) with low RSDs were achieved.