Cetylpyridinium cation

Figure 29 shows the dependence of the equilibrium concentration of the cetylpyridinium cations in the anionic gel of SMA-MAA, Cg, on the contents of CPB in the surrounding solution. At low Cs, the Cg values are higher by a factor of 104 than the value of CPB concentration in the solution and they are much higher than the critical micelle concentration (CMC) of CPB in water (3 x 10 4mol/l). One can assume that CPB cations in the gel should form micelle-like aggregates. 

We had used this fact to develop a new efficient gas chromatographic adsorbent, the Ce-sium/cetylpyridinium montmorillonite (Cs-CPM), containing 0.15 meq/g of Cs cations and 0.85 meq/g of cetylpyridinium cations in its exchange positions [55]. This adsorbent was imposed on an inert support together with the stationary liquid phase (SLP), namely, the polyphenylmethylsiloxane (PPMS) liquid, the dibutylt.etrachloroterephtalate, l,2,3-trans-(2cyanethoxy)propane in an amount of 3-15% mass. The Cs-CPM to SLP ratio was (2-3) l. 

In terms of total surfactant concentration, appreciable binding of dodecyl-and cetylpyridinium cation starts at the same total concentration, at about 1 X 10 5 mol dm 3, irrespective of the ionic strength of solutions. Above this concentration the heat effects that accompany the complexation of surfactant with the polyelectrolyte increase sharply, and their value can be partly attributed to the micellization of detergent. The viscosity and apparent molar volume measurements reveal that above cs 1 X 10 5 mol dm-3 extensive coiling of the chain around surfactant micelles takes place. In addition to this, the unusual behavior of molar conductivity in polyelectrolyte-surfactant solutions shows that an appreciable amount of small counterions may... 

Skerjanc J, Kogej K, Vesnaver G. Poly electrolyte-surfactant interactions. Enthalpy of binding of dodecyl- and cetylpyridinium cations to polyfstyrene-sulfonate) anion. J Phys Chem 1988 92 6382—6385. 

Kogej K, Skerjanc J. Binding of cetylpyridinium cation by poly(acrylic acid). Effect of polymer charge density. Acta Chim Slov 1999 46 269-279. 

The spectra show two resonances located around 2065 cm and 1965 cm . The first corresponds to linearly bound CO, the latter was assigned to CO in a bridge-bound position [786]. The conversion of CO in a bridging location into species atop has been identified with SFG [794]. The combination of the high light intensity (e.g. free-electron lasers) and the possibility to obtain absolute spectra without any modulation technique has allowed the detection of generally weak bands like those of over- and underpotential deposited hydrogen on a platinum electrode [795, 796]. Studies of coadsorption of cyanide anions and cetylpyridinium cations on Au(l 11) and Au(210) revealed marked differences [797]. CN is bound... 

The preparation of (m-Bu4N)2W60i9 reported hoe is a sunplifieation of the procedure given in this series by Fournier and Fuchs. Peroxotungstic salts are catalysts for the epoxidation of alkenes with hydrogen pCTOxide. In addition, the quaternary phosphonium and ammonium salts arc of special interest due to their solubUity in nonchlorinated solvents, buturrfortunatcly these salts are difficult to isolate because their preparations involve the use of biphasic conditions. In contrast, the preparation of the cetylpyridinium cation requires only aqueous solutions. 

The effect of concentration of cationic (cetylpyridinium chloride, CPC), anionic (sodium dodecylsulfate, SDS) and nonionic (Twin-80) surfactants as well as effect of pH value on the characteristics of TLC separ ation has been investigated. The best separ ation of three components has been achieved with 210 M CPC and LIO M Twin-80 solutions, at pH 7 (phosphate buffer). Individual solution of SDS didn t provide effective separation of caffeine, theophylline, theobromine, the rate of separ ation was low. The separ ation factor and rate of separ ation was increase by adding of modifiers - alcohol 1- propanol (6 % vol.) or 1-butanol (0.1 % vol.) in SDS solution. The optimal concentration of SDS is 210 M. 

The method developed by Epton [212,213] became the universally accepted method for the analysis of active matter of anionic and cationic surfactants. Epton s method, also known as the two-phase titration, is based on the titration of the anionic surfactant with cetylpyridinium bromide, a cationic surfactant, in the presence of methylene blue as indicator. A solution of the anionic surfactant is mixed with the indicator dissolved in dilute sulfuric acid, followed by further addition of chloroform, and then it is titrated with the cationic surfactant. Methylene blue forms a complex with the anionic salt that is soluble in chloroform, giving the layer a blue color. As the titration proceeds there is a slow transference of color to the water layer until the equivalence point. At the equivalence point colors of the chloroform and water layers are visually the same. On successive additions of titrant the chloroform layer lightens in shade and finally becomes colorless. 

Ong et al. [134] found that several hydrophilic anionic, non ionic, or cationic surfactants can alleviate the deleterious effect of magnesium stearate over-mixing on dissolution from capsules when added with the lubricant in a ratio as low as 1 5 (w/w). These successful surfactants were sodium A-lauroyl sarcosinate, sodium stearoyl-2-lactylate, sodium stearate, polox-amer 188, cetylpyridinium chloride, and sodium lauryl sulfate. The lipophilic surfactant glyceryl monostearate did not alleviate the magnesium stearate mixing effect. A reduction in thier particle size was shown to enhance effectiveness, particularly in the case of surfactants with low solubility and slow dissolution rate. 

Gillissen indicated that while cationic surfactants like cetylpyridinium chloride have a synergistic effect, Tween 80 inhibits the activity of gramicidin149. 

When strongly hydrophobic cationic surfactants are present in the mobile phase the hydrophobic surface of the stationary phase becomes dynamically conditioned with respect to the adsorption of the surfactant. This confers an ion-exchange capability on the stationary phase. Cassidy and Elchuk (32, 33) reported use of cetylpyridinium chloride to coat the stationary phase "permanently", but used tetrabutyl and tetramethylammonium salts in the mobile phase. Their equilibration procedure also employed the use of acetonitrile in the initial conditioning step, thus increasing the overall cost of the analysis. Knox and Hartwick (36)... 

Solutes. Toluene, although polarizable, was chosen as an apolar solute. Caffeine was chosen as a polar but nonionic solute. Four ionic solutes were tested benzyltrimethylammonium bromide (BTAB) is a cationic quaternary ammonium salt. Benzoic acid acts as an anionic solute at mobile phase pH values between 5.5 and 6.5 (the pK lies between 3.7 in CTAB solutions and 4.7 in SDS solutions)(4). Sodium paraoctylbenzene sulfonate (SOBS) (pK -0.8) and cetylpyridinium chloride (CPC) were chosen as ionic solutes having surfactant properties. Their hydrophobic "tails have the same lenghts as those of SDS and CTAB, respectively. 

In addition to divalent metal cations, trivalent and tetravalent cations (i.e. ln +, Ga +, Sb +, and Sn +) were also effective as linking agents to organize [Ge4Sio]" clusters to form hexagonally ordered mesostractures. In this case, cetylpyridinium bromide was nsed as the surfactant, and formamide served as the solvent. The mesophases made with Ga + and Sb + showed intense visible photoluminescence at77K. 

Quaternary ammonium compounds are surface-active agents. Some of them precipitate or denature proteins and destroy microorganisms. The most important disinfectants in this group are cationic surface-active agents, such as benzalkonium chloride, benzethonium chloride and methylbenzethonium chloride, and cetylpyridinium chloride the problems that they cause are similar. 

Cetylpyridinium chloride is a quaternary ammonium cationic surfactant, used in pharmaceutical and cosmetic formulations as an antimicrobial preservative see Section 10. It is used therapeutically as an antiseptic agent used alone or in combination with other drugs for oral and throat care used in nonparenteral formulations licensed in the UK and used in oral and inhalation preparations at concentrations of 0.02-1.5 mg (see Section 16). 

Carbon dioxide-free water Cationic emulsifying wax Ceratonia extract Cetylpyridinium bromide Chlorhexidine acetate Chlorhexidine gluconate Chlorhexidine hydrochloride Chlorodifluoromethane Chlorophenoxyethanol Com syrup solids m-Cresol o-Cresol p-Cresol... 

Other cationic surfactants, cetylpyridinium bromide (CP) [27], and Zephiramine [26] have been recommended for determining Ga in a ternary system with ECR. 

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