Sodium dodecylsulphate

The aim of this work is the development of pyrene determination in gasoline and contaminated soils. For this purpose we used room temperature phosphorescence (RTP) in micellar solutions of sodium dodecylsulphate (SDS). For pyrene extraction from contaminated soils hexane was used. Then exttacts earned in glass and dried. After that remains was dissolved in SDS solution in the presence of sodium sulphite as deoxygenation agent and thallium (I) nitrate as heavy atom . For pyrene RTP excitation 337 nm wavelength was used. To check the accuracy of the procedures proposed for pyrene determining by RTP, the pyrene concentrations in the same gasoline samples were also measured by GC-MS. 

Sodium dodecylsulphate was selected as an anionic surfactant Factors affecting acid-induced cloud point extraction including surfactant, hydrochloric acid, PAHs, and electrolyte concentration, centrifugation have been examined. Finally, we applied the optimized acid-induced CPE system for combination of the extraction and preconcentration steps with fluorimetric determination of some representatives of PAHs. Suggested means was used for PAHs determination in tap water. 

The Water Unextractable Solids were isolated from dehulled, defatted, untoasted soy bean meal (particle size < 0.5 mm) by removal of cold water solubles, proteins and starch. The soy bean meal was extracted with cold water, a solution containing sodium dodecylsulphate and 1,4-dithiothreitol, and incubated with a-amylase, to yield the CWS, SDSS and HWS... 

JH DeSmidt, JCA Offringa, DJA Crommelin. Dissolution kinetics of griseofulvin in sodium dodecylsulphate solutions. J Pharm Sci 76 711-714, 1987. 

Polystyrene latexes were similarly prepared by Ruckenstein and Kim [157]. Highly concentrated emulsions of styrene in aqueous solutions of sodium dodecylsulphate, on polymerisation, yielded uncrosslinked polystyrene particles, polyhedral in shape and of relative size monodispersity. Interestingly, Ruckenstein and coworker found that both conversions and molecular weights were higher compared to bulk polymerisation. This was attributed to a gel effect, where the mobility of the growing polymer chains inside the droplets is reduced, due to increased viscosity. Therefore, the termination rate decreases. 

Human biotinidase is a monomeric glycoprotein with a molecular mass of 76 kDa when analysed by sodium dodecylsulphate-polyacrylamide gel electrophoresis [7]. The cDNA for human biotinidase was isolated and sequenced in 1994 by Cole and coworkers [6]. The deduced protein contains 502 amino acids, has a molecular mass of 57 kDa and contains 6 potential N-linked glycosylation sites. The biotinidase gene... 

Table 8.2.3 Common loading buffer (5 x solution). EDTA Ethylenediaminetetraacetic acid, SDS sodium dodecylsulphate...

Sodium dodecylsulphate (SDS, sodium laurylsulphate) [151-21-3] M 288.4, m 204-207°. Purified by Soxhlet extraction with pet ether for 24h, followed by dissolution in acetone MeOH H20 90 5 5(v/v) and recrystn [Politi et al. JPC 89 2345 1985], Also purified by two recrystns from absolute EtOH, aqueous 95% EtOH, MeOH, isopropanol or a 1 1 mixture of EtOH isopropanol to remove dodecanol, and dried under vacuum [Ramesh and Labes JACS 109 3228 1987. Also purified by foaming [see Cockbain and McMullen TFS 47 322 7957] or by liquid-liquid extraction [see Harrold J Colloid Sci 15 280 I960]. Dried over silica gel. For DNA work it should be dissolved in excess MeOH passed through an activated charcoal column and evaporated until it crystallises out. 

This technique is a variant of CZE. A cationic or anionic surfactant compound, such as sodium dodecylsulphate, is added to the mobile phase to form charged micelles. These small spherical species, whose core is essentially immiscible with the solution, trap neutral compounds efficiently by hydrophylic/hydrophobic affinity interactions (Fig. 8.7). Using this type of electrophoresis, optical purity analysis can be conducted by adding cyclodextrins instead of micelles to the electrolyte. This is useful for separating molecules that are not otherwise separable. Under such conditions, the enantiomers form inclusion complexes of different stability with cyclodextrin (cf. 3.6). 

Nakahori, C. and Nakai, S. 1972. Fractionation of caseins directly from skim milk by gel chromatography. I. Elution with sodium dodecylsulphate. J. Dairy Sci. 55, 25-29. 

At higher concentration of other cationic surfactants, cetylammonium chloride and bromide, the anionic surfactant sodium dodecylsulphate or the nonionic surfactant nonylphenol(ethoxylate)28(propoxylate)i3... 

Figure 5. Volume fraction of polystyrene (PS) particles in zinc against the concentration of various surfactants at j = 0.5 kA til 2, 4 PS = 0.02 54 76 (a) Cetylpyrridinium chloride (A) Sodium dodecylsulphate (o) and Nonylphenol(etho ylate>28(pFopoxylate)i3 ( ) (b) ...

The edges of this dodecahedron sized a - 8.5 cm. When the volume of the rubber balloon at inflation became bigger than the volume of the sphere inscribed in the dodecahedron, the balloon was deformed by the dedecahedron faces and took a shape close to the respective shape of a bubble in a monodisperse dodecahedral foam with a definite expansion ratio. The expansion ratio of the foam was determined by the volume of liquid (surfactant solution or black ink in the presence of sodium dodecylsulphate) poured into the dodecahedron. An electric bulb fixed in the centre of the balloon was used to take pictures of the model of the foam cell obtained. The film shape and the projection of the borders and vertexes on the dodecahedron face are clearly seen in Fig. 1.10. 

The fructosyltransferase from A. aculeatus displayed activity without the addition of any metal ions. However, some effects were observed in its susceptibUity to mono- and divalent cations [33]. For ejample, Mn, K, and Co caused a 1.4—1.9-fold increase in the activity, whereas low concentrations of Hg and Zn produced 35-60% inhibition. It was also found that the enzyme was slightly activated by several non-ionic and anionic surfactants such as sodium dodecylsulphate (1.5-fold at lOmM), sodium deoxycholate (1.4-fold at ImM), and Triton X-100 (1.4-fold at 5% w/v). Moreover, it was resistant to low concentrations (1-lOmM) of reducing agents such as dithiothreitol and P-mercaptoethanol. 

Measurements of the fluorescence and cheml1uminescence spectra of IRu(bpy)3] in aqueous sodium dodecylsulphate show that the ruthenium complex is bonded to the stir f actant micelle. Chemiluminescent reactions of fRu(bpy)3] and (Ru(bpy)3with solvent acetonitrile and also of r.MogCl 4l and [llOgCl ] " under the same conditions have been reported. 

Precipitate flotation is applied in the analysis of natural waters. Trace ions in an aqueous solution are co-precipitated with colloidal metal hydroxide collectors and floated with the aid of a gas stream [94-96]. Tiny gas bubbles are trapped in the interstitial spaces and on the surfaces of the precipitates to give sufficient buoyancy. Surfactant ions having the charge opposite to the precipitate surfaces are used to make the surface hydrophobic. Another important role of the surfactants e.g., sodium oleate, sodium dodecylsulphate) is to form a stable froth layer to support the precipitate on the solution surface, which is important for complete separation of the precipitate. 

FIGURE 2.9. Migration boundary map obtained by the migration behavior of three components. The feasible experimental region is indicated. SDS = sodium dodecylsulphate. 

CuS has also been prepared [ 36 ] by using Cu-ammonia complex and thiourea in alkaline pH in a water/cyclohexane/Triton X100/methylpropane-l-ol microemulsion. Other nonionic surfactants as well as ionic sodium dodecylsulphate were also used. Biswas et al. [29] synthesised CuS nanoparticles in water/cyclohexanone/Triton X100/i-propanol w/o microemulsion. The band gap of the material and the particle growth were determined from spectral and DLS measurements along with their general characterisation. 

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