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Octyl sulfate

In the author s group, much lower-melting benzenesulfonate, tosylate, or octyl-sulfate ionic liquids have recently been obtained in combination with imidazolium ions. These systems have been successfully applied as catalyst media for the biphasic, Rh-catalyzed hydroformylation of 1-octene [14]. The catalyst activities obtained with these systems were in all cases equal to or even higher than those found with the commonly used [BMIM][PF6]. Taking into account the much lower costs of the ionic medium, the better hydrolysis stability, and the wider disposal options relating to, for example, an octylsulfate ionic liquid in comparison to [BMIM][PF6], there is no real reason to center future hydroformylation research around hexafluorophosphate ionic liquids. [Pg.240]

The aggregation numbers of alcohol sulfates can be as low as 20 for sodium octyl sulfate in water solution but usually range from 60 to 150 for higher alcohol sulfates. [Pg.255]

High Performance Liquid Chromatographic (HPLC) Analysis. A Waters HPLC system (two Waters 501 pumps, automated gradient controller, 712 WISP, and 745 Data module) with a Shimadzu RF-535 fluorescence detector or a Waters 484 UV detector, and a 0.5 pm filter and a Rainin 30 x 4.6 mm Spheri-5 RP-18 guard column followed by a Waters 30 x 3.9 cm (10 pm particle size) p-Bondapak C18 column was used. The mobile phase consisted of a 45% aqueous solution (composed of 0.25% triethylamine, 0.9% phosphoric acid, and 0.01% sodium octyl sulfate) and 55% methanol for prazosin analysis or 40% aqueous solution and 60% methanol for naltrexone. The flow rate was 1.0 mL/min. Prazosin was measured by a fluorescence detector at 384 nm after excitation at 340 nm (8) and in vitro release samples of naltrexone were analyzed by UV detection at 254 nm. [Pg.105]

A universal eluent system was proposed for analysis of amino acids in biological fluids by IEC on the cation exchange resin Ostion LG ANB134. A study was carried out on the effect of the carrier pH on RP-HPLC of amines, using a Cs column and octyl sulfate as ion pairing reagent. Optimal results were obtained for the analysis of catecholamines... [Pg.1067]

Aspartic and glutamic acids were not retained in a buffer solution without a counter-ion however, these acids were retained by the addition of octyl sulfate to the eluent, as seen in Figure 4.12. These amino acids can form a complex with copper ions and will be retained on the stationary phase. The addition of both a counter-ion and copper ions further increased the retention and made possible... [Pg.72]

Catecholamine Octyl sulfate Cl8 silica 50 mM Citric acid + 50 pM EDTA in 50 mM Na2HP04 (2 1) 34... [Pg.76]

The addition of a surfactant counter-ion reduced the retention factor at low pH due to the surface modification of the stationary phase material. Covering the surface of the stationary phase with the surfactant reduces the hydro-phobicity of the stationary phase material. The addition of the tetrabutyl-ammonium counter-ion increased the retention factor at high pH. The pKa of the indole acetate was 5.15 without surfactant, 4.85 with octyl sulfate ion, and 5.60 with tetrabutylammonium ion. That is, the addition of a same-charged hydrophobic ion reduced the pKa value, and the addition of the counter-ion increased the pKa value. The difference in the pKa value on the addition of surfactant is not constant it is affected by the kind of ion and the concentration. It is difficult to estimate the pKa change. [Pg.79]

Figure 4.17 Selectivity of counter-ion for the retention of indoleacetic acid. Column, Hitachi 3011 (polystyrene gel), 25 cm x 4.1 mm i.d. eluent, 50 mM sodium phosphate (NaP) containing 25 mM tetrabutylammonium (TBA) or octyl sulfate (C8) ion in 20% acetonitrile solution flow rate, 1ml min-1 temperature, 40 °C detection, UV 254 nm. Figure 4.17 Selectivity of counter-ion for the retention of indoleacetic acid. Column, Hitachi 3011 (polystyrene gel), 25 cm x 4.1 mm i.d. eluent, 50 mM sodium phosphate (NaP) containing 25 mM tetrabutylammonium (TBA) or octyl sulfate (C8) ion in 20% acetonitrile solution flow rate, 1ml min-1 temperature, 40 °C detection, UV 254 nm.
Scheme 3.2 Enantioselective microbial hydrolysis of rac-2-octyl sulfate using whole resting cells of Pseudomonas spp. through inversion of configuration... Scheme 3.2 Enantioselective microbial hydrolysis of rac-2-octyl sulfate using whole resting cells of Pseudomonas spp. through inversion of configuration...
Letcher, T.M. et al.. Determination of activity coefficients at infinite dilution of solutes in the ionic liquid l-butyl-3-methylimidazolium octyl sulfate using gas-liquid chromatography at the temperature 298.15 K, 313.15 K or 328.15 K, /. Chem. Eng. Data, 50,1294, 2005. [Pg.70]

As for the carboxylates, the remote site fragmentation Is much more pronounced with Increasing carbon chain length. For example, fragmentation Is seen for octyl sulfate but Is much more pronounced for longer-chained sulfates such as hexadecyl sulfate. [Pg.202]

Nevertheless, the octyl sulfate CAD spectrum yields sufficient information to allow the compound to be distinguished from isomeric 2-ethylhexyl sulfate (for a comparison, see ref. 8). The branching of the 2-ethylhexyl sulfate causes suppression of fragmentation at the branch point in a fashion analogous to that seen for the carboxylates and for the steroid (see Figure 3). [Pg.204]

S.D. Christian, E.E. Tucker and E.H. Lane, Precise vapor-pressure measurements of the solubilization of cyclohexane by sodium octyl sulfate and sodium octyl sulfate micelles, J. Colloid Interface Sci. 84 (1981) 423-432. [Pg.298]

Danielsson et al. [25] have studied the synthesis of PEDOT in ionic liquids that utilize bulky organic anions, l-butyl-3-methylimidazolium diethylene glycol monomethyl ether sulfate and l-butyl-3-methylimidazolium octyl sulfate, the latter of which is a solid at room temperature and thus requires the addition of either monomer or solvent (in this case water) to form a liquid at room temperature. Polymerization in a water-free ionic liquid was only possible in the octyl sulfate species, but the polymerization of EDOT was successful in aqueous solutions of both the ionic liquids (0.1 M). The ionic liquid anions appear to be mobile within the polymer, exchangeable with chloride ions at a polymer/KCl(aq) interface, but it is interesting that when the PEDOT is in aqueous solutions of the ionic liquid, at higher concentrations (0.01-0.1 M) the imidazolium cation can suppress this anion response. The ion mobility in both the ionic liquid and in the polymer film in contact with the solution is significantly increased by addition of water. [Pg.191]

Sodium octyl sulfate -I- H3O+ Sodium decyl sulfate + OH Sodium decyl sulfate -t- H2O... [Pg.320]

Figure 4-44. Capacity factor of tyrosinamide versus concentrations of dodecyl sulfate (upper curve), decyl sulfate (middle curve), and octyl sulfate (lower curve). (Reprinted from reference 119, with permission.)... Figure 4-44. Capacity factor of tyrosinamide versus concentrations of dodecyl sulfate (upper curve), decyl sulfate (middle curve), and octyl sulfate (lower curve). (Reprinted from reference 119, with permission.)...
The adsorption of binary mixtures of anionic surfactants of a homologous series (sodium octyl sulfate and sodium dodecyl sulfate) on alpha aluminum oxide was measured. A thermodynamic model was developed to describe ideal mixed admicelle (adsorbed surfactant bilayer) formation, for concentrations between the critical admicelle concentration and the critical micelle concentration. Specific... [Pg.205]

Fig. 5-38. Separation of fatty alcohol sulfates with various chain lengths. - Separator column IonPac NS1 (10 pm) eluent (A) 0.02 mol/L NH4OH / acetonitrile (80 20 v/v), (B) 0.02 mol/L NH4OH / acetonitrile (20 80 v/v) gradient linear, 100% A to 100% B in 25 min flow rate 1 mL/ min detection suppressed conductivity injection volume 50 jiL solute concentrations 1. 80 mg/ L Rewopol NLS 28 II. 80 ppm each of octyl sulfate (1), decyl sulfate (2), dodecyl sulfate (3), tetradecyl sulfate (4), and hexadecyl sulfate (5). Fig. 5-38. Separation of fatty alcohol sulfates with various chain lengths. - Separator column IonPac NS1 (10 pm) eluent (A) 0.02 mol/L NH4OH / acetonitrile (80 20 v/v), (B) 0.02 mol/L NH4OH / acetonitrile (20 80 v/v) gradient linear, 100% A to 100% B in 25 min flow rate 1 mL/ min detection suppressed conductivity injection volume 50 jiL solute concentrations 1. 80 mg/ L Rewopol NLS 28 II. 80 ppm each of octyl sulfate (1), decyl sulfate (2), dodecyl sulfate (3), tetradecyl sulfate (4), and hexadecyl sulfate (5).
Figure 13.6 Indirect detection of anions and cations. Stationary phase //-Bondapak-Phenyl. Mobile phase naphthalene-2-sulfonate 4 x 10 M in 0.05 M phosphoric acid. Sample (1) butyl sulfate, (2) pentyl amine, (3) hexane sulfonate, (4) hep-tylamine (5) octane sulfonate (6) octyl sulfate (S) system peak. Reproduced with permission from J. Crommen, G. Schill, D. West-erlund and L. Hackzell, Chromatographia, 24 (1987) 252 (Fig. 1). Figure 13.6 Indirect detection of anions and cations. Stationary phase //-Bondapak-Phenyl. Mobile phase naphthalene-2-sulfonate 4 x 10 M in 0.05 M phosphoric acid. Sample (1) butyl sulfate, (2) pentyl amine, (3) hexane sulfonate, (4) hep-tylamine (5) octane sulfonate (6) octyl sulfate (S) system peak. Reproduced with permission from J. Crommen, G. Schill, D. West-erlund and L. Hackzell, Chromatographia, 24 (1987) 252 (Fig. 1).
Figure 13.1 Analysis of catecholamines in urine (reproduced with permission of Bioanalytical Systems). Conditions stationary phase, octylsilane mobile phase, citrate-phosphate buffer (pH 4) containing 7% methanol and SOrngl" sodium octyl sulfate electrochemical detector, +700 mV for sample preparation see R.M. Riggin et a ., Anal. Chem., 49, 2109 (1977). Peaks (with concentrations in urine) 1 = norepinephrine (160ngml ) 2 = epinenphrine (31ngml ) 3 = dopamine (202ngmr ) IS —3,4-dihydroxybenzylamine (internal standard). Figure 13.1 Analysis of catecholamines in urine (reproduced with permission of Bioanalytical Systems). Conditions stationary phase, octylsilane mobile phase, citrate-phosphate buffer (pH 4) containing 7% methanol and SOrngl" sodium octyl sulfate electrochemical detector, +700 mV for sample preparation see R.M. Riggin et a ., Anal. Chem., 49, 2109 (1977). Peaks (with concentrations in urine) 1 = norepinephrine (160ngml ) 2 = epinenphrine (31ngml ) 3 = dopamine (202ngmr ) IS —3,4-dihydroxybenzylamine (internal standard).
As already mentioned, if the van der Waals force (or other attractive force) is not predominant, first a dimple forms in the thinning liquid films. Usually the dimple exists for a short period of time initially it grows, but as a result of the swift outflow of liquid it decreases and eventually disappears. The resulting plane-parallel film thins at almost constant radius R. When the electrostatic repulsion is strong, a thicker primary film forms (see point 1 in Figure 5.13). From the viewpoint of conventional DLVO theory, this film must be metastable. Indeed, the experiments with microscopic foam films, stabilized with sodium octyl sulfate or sodium dodecyl sulfate in the presence of different amount of electrolyte, show that a black spot may suddenly form and a transition to... [Pg.230]


See other pages where Octyl sulfate is mentioned: [Pg.284]    [Pg.570]    [Pg.144]    [Pg.25]    [Pg.145]    [Pg.110]    [Pg.193]    [Pg.624]    [Pg.624]    [Pg.31]    [Pg.298]    [Pg.90]    [Pg.81]    [Pg.83]    [Pg.83]    [Pg.85]    [Pg.695]    [Pg.209]    [Pg.120]    [Pg.489]    [Pg.739]    [Pg.156]    [Pg.1151]    [Pg.619]    [Pg.801]    [Pg.221]   
See also in sourсe #XX -- [ Pg.274 ]

See also in sourсe #XX -- [ Pg.2 , Pg.620 ]

See also in sourсe #XX -- [ Pg.427 ]




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