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Surfactant chromatography

Mass-action model of surfactant micelle formation was used for development of the conceptual retention model in micellar liquid chromatography. The retention model is based upon the analysis of changing of the sorbat microenvironment in going from mobile phase (micellar surfactant solution, containing organic solvent-modifier) to stationary phase (the surfactant covered surface of the alkyl bonded silica gel) according to equation ... [Pg.81]

The model was tested by the micellar liquid chromatography separ ation of the five rarbornicin derivatives and four ethers of hydroxybenzoic acid. Micellar mobile phases were made with the sodium dodecylsulfate and 1-pentanol or isopentanol as modifier. In all cases the negative signs of the coefficients x and y indicate that at transition of the sorbat from the mobile on the stationar y phase the number of surfactant monomers as well as the number of modifier molecules increases in its microenvironment. [Pg.81]

One of trends of development of thin-layer chromatography implies that replacement of aqueous-organic eluents by micellar surfactants solution. This is reduces the toxicity, flammability, environmental contamination and cost of the mobile phases, reduce sample prepar ation in some cases. [Pg.350]

Nonionic surfactants, including EO-PO block copolymers, may be readily separated from anionic surfactants by a simple batch ion exchange method [21] analytical separation of EO-PO copolymers from other nonionic surfactants is possible by thin-layer chromatography (TLC) [22,23] and paper chromatography [24], and EO-PO copolymers may themselves be separated into narrow molecular weight fractions on a preparative scale by gel permeation chromatography (GPC) [25]. [Pg.768]

Thin-layer chromatography (TLC) is used both for characterization of alcohol sulfates and alcohol ether sulfates and for their analysis in mixtures. This technique, combined with the use of scanning densitometers, is a quantitative analytical method. TLC is preferred to HPLC in this case as anionic surfactants do not contain strong chromophores and the refractive index detector is of low sensitivity and not suitable for gradient elution. A recent development in HPLC detector technology, the evaporative light-scattering detector, will probably overcome these sensitivity problems. [Pg.283]

The amount of residual sulfonate ester remaining after hydrolysis can be determined by a procedure proposed by Martinsson and Nilsson [129], similar to that used to determine total residual saponifiables in neutral oils. Neutrals, including alkanes, alkenes, secondary alcohols, and sultones, as well as the sulfonate esters in the AOS, are isolated by extraction from an aqueous alcoholic solution with petroleum ether. The sulfonate esters are separated from the sultones by chromatography on a silica gel column. Each eluent fraction is subjected to saponification and measured as active matter by MBAS determination measuring the extinction of the trichloromethane solution at 642 nra. (a) Sultones. Connor et al. [130] first reported, in 1975, a very small amount of skin sensitizer, l-unsaturated-l,3-sultone, and 2-chloroalkane-l,3-sultone in the anionic surfactant produced by the sulfation of ethoxylated fatty alcohol. These compounds can also be found in some AOS products consequently, methods of detection are essential. [Pg.444]

Besides the above-mentioned titration methods, some special instrumentical analytical ones were established in recent years. A big advantage lies in the fact that single components can be detected even in complex mixtures by using chromatographic methods. Gas chromatography fails to analyze nonvolatile surfactant molecules. To get volatile components, chemical manipulations have to be... [Pg.515]

The alkanephosphonic acid dichlorides obtained by these methods are converted with amines, with all reactions carried out in solvents such as acetone, benzene, or diethyl ether at 10°C with triethylamine as HC1 captor. The conversion runs quantitatively followed by a purification with the help of column chromatography with chloroform/methanol in a ratio of 9 1 as mobile phase. The alkanephosphonic acid bisdiethanolamides could be obtained as pure substances with alkane residues of C8, C10, C12, and Ci4. The N-(2-hydroxyethane) alkanephosphonic acid 0,0-diethanolamide esters were also prepared in high purity. The obtained surfactants are generally stable up to 100°C. Only the alkanephosphonic acid bismonomethylamides are decomposed beneath this temperature forming cyclic compounds. [Pg.581]

The neutral surfactant is measured after fixing of the ionic substances on a combined anionic/cationic ion exchange column. Volatile substances in the eluate are determined by gas chromatography and nonvolatile substances are measured gravimetrically. In the bulk of the neutral compounds phosphoric acid triesters may be present. This part is additionally determined by atom emission spectroscopy. [Pg.617]

Di Corcia A, C Crescenzi, A Marcomini, R Samperi (1998) Liquid-chromatography-electrospray-mass spectrometry as a valuable tool for characterizing biodegradation intermediates of branched alcohol ethoxyl-ate surfactants. Environ Sci Technol 32 711-718. [Pg.271]

R., Khaledi, M. G. Quantitative structure-activity relationships studies with micellar electrokinetic chromatography. Influence of surfactant type and mixed micelles on estimation of hydrophobicity and bioavailability. J. Chromatogr. A 1996, 727, 323-335. [Pg.354]

The synergism of surfactant-polymer complex formation has been studied by gel permeation chromatography [114],... [Pg.206]

Kawase, J., Ueno, H., and Tsuji, K., Analysis of amphoteric surfactants by liquid chromatography with post-column detection. I. Mono- and dialanine surfactants, /. Chromatogr., 264, 415, 1983. [Pg.195]

Biinger, H., Kaufner, L., and Pison, U., Quantitative analysis of hydrophobic pulmonary surfactant proteins by high-performance liquid chromatography with light-scattering detection, /. Chromatogr. A, 870, 363, 2000. [Pg.381]

Capillary electrophoresis employing chiral selectors has been shown to be a useful analytical method to separate enantiomers. Conventionally, instrumental chiral separations have been achieved by gas chromatography and by high performance liquid chromatography.127 In recent years, there has been considerable activity in the separation and characterization of racemic pharmaceuticals by high performance capillary electrophoresis, with particular interest paid to using this technique in modem pharmaceutical analytical laboratories.128 130 The most frequently used chiral selectors in CE are cyclodextrins, crown ethers, chiral surfactants, bile acids, and protein-filled... [Pg.405]


See other pages where Surfactant chromatography is mentioned: [Pg.21]    [Pg.117]    [Pg.93]    [Pg.134]    [Pg.21]    [Pg.117]    [Pg.93]    [Pg.134]    [Pg.610]    [Pg.270]    [Pg.377]    [Pg.159]    [Pg.233]    [Pg.111]    [Pg.342]    [Pg.350]    [Pg.384]    [Pg.770]    [Pg.202]    [Pg.284]    [Pg.493]    [Pg.539]    [Pg.541]    [Pg.463]    [Pg.382]    [Pg.226]    [Pg.236]    [Pg.77]    [Pg.744]    [Pg.483]    [Pg.210]    [Pg.260]    [Pg.602]    [Pg.777]    [Pg.63]    [Pg.228]    [Pg.377]    [Pg.419]   
See also in sourсe #XX -- [ Pg.64 , Pg.65 ]

See also in sourсe #XX -- [ Pg.93 ]




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Cationic surfactants chromatography

Further purification of the microbubble surfactant mixture by gel-filtration column chromatography

High performance liquid chromatography anionic surfactants

High performance liquid chromatography cationic surfactants

High-performance liquid chromatography surfactants

Micellar electrokinetic chromatography surfactant

Micellar electrokinetic chromatography surfactants used

Polymeric surfactant electrokinetic chromatography

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