Sodium dodecyl sulfate INDEX

Sodium dodecyl sulfate present in hydrophilic ointments has been determined by TLC on silica gel with flame ionization detection, which was considered better than the colorimetric method. TLC is preferred to HPLC in this case due to the low sensitivity of the refractive index detector that makes difficult the analysis of small amounts of sodium dodecyl sulfate [284]. 

FIG. 8.4 Determination of the microenvironment of a molecule (a) a portion of the ultraviolet spectrum of benzene in (1) heptane, (2) water, and (3) 0.4 M sodium dodecyl sulfate and (b) ratio of the intensity of the solvent-induced peak to that of the major peak for benzene versus the index of solvent polarity. The relative dielectric constant is also shown versus the index of polarity. (Redrawn, with permission, from P. Mukerjee, J. R. Cardinal, and N. R. Desai, In Micellization, Solubilization and Microemulsions, Vols. 1 and 2 (K. L. Mittal, Ed.), Plenum, New York, 1976.)... 

SD standard deviation SDE simultaneous distillation extraction SDS sodium dodecyl sulfate SFC solid fat content SFI solid fat index SHAM salicylhydroxamic acid SIM selected ion monitoring SNIF-NMR site-specific natural isotope fractionation measured by nuclear magnetic resonance spectroscopy SP-HPLC straight-phase high-performance liquid chromatography... 

Fig. 11. (a) Far ultraviolet rotatory dispersion of ribonuclease. Corrected mean residue specific rotation vs. wavelength [to R = [aLAf/100 [3/(n2 + 2)l where a — specific rotation, M mean residue weight, and n = solvent refractive index. Bars give maximal deviation at peaks. Reproduced from Jirgensons (311). (b) Near ultraviolet rotatory dispersion of 0.48% pancreatic ribonuclease in a 1-mm cell, in (a) 0.15 M phosphate buffer at pH 62 (b) 0.15 M glycine-NaOH buffer at pH 11.5 (c) 0.1 N HC1 (d) 15% sodium dodecyl sulfate. Reproduced from Glazer and Simmons (313). (c) Far ultraviolet circular dichroic spectra of RNase-A, RNase-S, and S-protein at 25° and 3°. Reproduced from Pflumm and Beychok (313). (d) Near ultraviolet circular dichroic spectra of RNase-A as a function of pH. Reproduced from Pflumm and Beychok (313). 

The most popular method of electrophoretic separation by gels employs sodium dodecyl sulfate (SDS). This method not only gives an index of protein purity but yields an estimate of the protein subunit molecular weights. The mixture of proteins to be characterized is first completely denatured by adding SDS (a detergent) and mercaptoethanol and by briefly heating the mixture. Denaturation is caused by the association of the apolar tails of the SDS molecules with protein hydrophobic groups. Any cystine disulfide... 

A reactor was charged with water (490 g), sodium dodecyl sulfate (0.56 g), acrylonitrile (8.8 g), and cumenyl thiobenzoic acid (1.09) and then heated to 80°C for 20 minutes. This solution was treated with 4,4 -azobis(4-cyanovaleric acid) (0.93 g) and additional water (25 g) and then stirred for 30 minutes. Thereafter additional acrylonitrile (45.0 g) was added dropwise over 1 hour, and the mixture heated for approximately 5 hours. A sample was taken that indicated thepolymer had aMwOf 13,700daltonsandM of 10,300daltons with a polydispersity index of 1.33. The mixture was then treated with n-butyl acrylate (20.0 g), 4,4 -azobis(4-cyanovaleric acid) (0.40 g), and water (10 g) and stirred 1 hour at 80°C. The mixture was further treated with n-butyl acrylate (80.0 g) over 2 hours and... 

Figure 1 Relationships of S with interfacial tension and emulsifying activity of proteins. I, bovine serum albumin 2, /3-lactoglobulin 3. trypsin 4, ovalbumin 5, conalbuntin 6, lysozyme 7, K-casein 8, 9, I0, II, and 12, denatured ovalbumin by heating at 85°C for l, 2, 3, 4, and 5 min respectively 13, 14, 15, 16. 17, and 18. denatured lysozyme by heating at 85"C for l, 2, 3, 4, 5, and 6 min respectively 19, 20, 21, 22, and 23, ovalbumin bound with 0.2, 0.3, 1.7, 5.7, and 7.9 mol of sodium dodecyl sulfate/mol of protein respectively 24, 25, 26, 27, and 28, ovalbumin bound with 0.3, 0.9, 3.1,4.8, and 8.2 mol of linoleate/mol of protein respectively. Interfacial tension measured at corn oil/0.20c protein interface with a Fisher Surface Tensiontat Model 21. Emulsifying activity index calculated from the absorbance at 500 nm of the supernatant after centrifuging blended mixtures of 2 ml of corn oil and 6 ml of 0.5% protein in 0.01 M phosphate buffer, pH 7.4 S initial slope of fluorescence intensity (FI) vs. percent protein plot. 10 /al of 3.6 mM m-parinaric acid solution was added to 2 ml of 0.002 to 0.1% protein in 0.01 M phosphate buffer, pH 7.4, containing 0.002% SDS. FI was measured at 420 nm by exciting at 325 nm. (From Ref. 2. Reprinted by permission.)...

Picomole (10 mol) Polyaromatic hydrocarbon Refractive index Reversed phase Sodium dodecyl sulfate Signal-to-noise ratio Solute retention time Void volume of system Triethylamine Trifluoroacetic acid Tetrahydrofuran Ultraviolet... 

Figure 4.6. Variation of the sodium dodecyl sulfate CMC at temperatures between 20 and 30 C as obtained by various experimental methods. a, specific conductivity b, equivalent conductivity c, other conductance d, surface tension versus logarithm of concentration e, other relationships between surface tension and concentration f, absorbance g, solubilization h, light scattering i, other methods such as refractive index, emf, vapor pressure, sound velocity, and viscosity.

Ethylhexyl acrylate and 2-ethylhexyl methacrylate from Huka, Switzerland and the synthesized Ce-12 alkyl acrylates and methacrylates were distilled under reduced pressme to remove the inhibitor. Potassium persulfate (KPS) from Sisco Chemicals, Mumbai, India and sodium dodecyl sulfate (SDS) from Qualigens, Mmnbai, India were used as received. The paraffin base oil SN 500 with a viscosity index of 90 was received from Savita Chemicals, Mumbai, India. Commercial VI improver ORTHOLEUM, which is a product of Associated Octel Ltd., U.K. was obtained from Prashant Hydrocarbon Pvt. Ltd., Baroda, India. All solvents were distilled before use and double-distilled deionized water was used throughout the work. 

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