Dioctadecyl

Octadecyl ether (dioctadecyl ether) [6297-03-6] M 523.0, m 59.4°. Vacuum distd, then crystd from MeOH/ benzene. 

NMR spectroscopy is most effective in qualitative analysis when the samples examinated are substantially pure compounds and has been used to confirm the theoretically predicted low-energy conformations of the Af-acylated hindered amine light stabiliser Tinuvin 440 [210]. Trace amounts of PDMS (quantification limit 0.1 ppm) in plastic additives, dyes and pigments were determined by 111 NMR after Soxhlet extraction [211]. ll NMR was also used for the detection of octadecanol, an impurity in Irganox PS 802 (3,3 -dioctadecyl thiodipropionate). NMR has identified the nature of a supposedly UV stabiliser of empirical formula C17H18N3CIO [44] (Scheme 5.2). 

It is also possible to separate and detect antioxidants by SEC. This can be useful for the antioxidants that are strongly retained on Ci8 HLPC columns such as Irganox PS802 (thiodipropionic acid, dioctadecyl ester). 

PM 49840 02500-88-1 Hostanox SE10 Dioctadecyl disulfide 3 570.52 Not examined Unlikely to readily ionise. Best examined by GC-MS ... 

PM 93280 00693-36-7 Irganox PS802 Thiodipropionic acid, dioctadecyl ester 5 682.59 Not examined but after Irganox 1076 (Note 1) 683.6 (+ve) Not examined... 

By immobilizing Mn(III)-tetrakis(4-sulfonatophenyl)-porphyrin on dioctadecyl-dimethyl ammonium chloride bilayer membranes incorporated into a PVC film, Kuniyoshi et al. [65] developed an epinephrine CL sensor, which allowed determination of epinephrine down to 3 pM with an RSD of 1.0% for 50 pM of this biological compound. Compared with the previously reported epinephrine CL sensor [66], the present authors noted that the alkaline carrier solution, at high concentration levels, caused gradual deterioration of the immobilized catalyst, and this problem could be solved by the use of immobilization techniques other than ion exchange, e.g., solubilization of the catalyst that has octadecyl groups in the bilayer molecules. 

The mixed mode of sorption of the dye l,l -dioctadecyl-3,3,3, 3 -tetramethylindocar-bocyanine pechlorate (Dil) at the interface of an ODS stationary phase and ACN-water mobile phase was studied by single-molecule resolution and fluorescence imaging techniques. The measurements indicated that minimally four types of adsorption sites are present on the surface of the ODS stationary phase. The desorption times of the dye are different at the different adsorption sites resulting in a deformed peak shape [152],... 

DJ. Swinton and M.J. Wirth, Lateral diffusion of l,l -dioctadecyl-3,3,3, 3 -tetramethylindo-carbocyanine perchlorate at the interfaces of C-18 and chromatographic solvents. Anal. Chem., 72 (2000) 3725-3730. 

Takafuji, M., Rahman, A.M., Ansarian, H.R., Derakhshan, M., Sakurai, T., and Ihara, H., Dioctadecyl L-glntamide-derived lipid-grafted silica as a novel organic stationary-phase for RP-HPLC, J. Chrvmatogr. A, 1074, 223, 2005. 

Investigation of thermodynamic behavior of monolayers formed from mixtures of bis[2-(n-hexadecanoyl)ethyl]methyl(4-vinylbenzyl) ammonium chloride (1) and dioctadecyl-dimethylammonium bromide (5) serves as the second example [116]. The determined surface-pressure/surface-area isotherms of mono-layers prepared from (1) and (5) and from their mixtures are given in Fig. 8. The isotherms showed the expected behavior following the liquid state there was a transition to the solid state in the region of 20-36 mNm 1. This transition was characterized by a pressure, and by a corresponding area, Aj. All isotherms intersected in the vicinity of 30 mNm-1 and, at surface-pressure/surface-area... 

Cast multibilayers prepared from N-(co-(trimethyl-ammonio)undecanoyl) dioctadecyl-L-glutamate bromide dispersions Fe304 particles generated in situ Magnetic anisotropy of particles was retained in cast multibilayer films 797... 

Fig. 133. Artist s conception of colloidal Fe304 particles incorporated in dioctadecyl-dimethylam-monium cation vesicles containing benzophenone ( ). Positions and dimensions of Fe304 particles need not be taken literally [789]...

In the present study, therefore, lipid membranes were used as transducers of taste information. Artificial lipid materials, such as dioleyl phosphate (DOPH) or dioctadecyl-dimethyl-ammonium, were used to construct a lipid membrane and responses of electrical potential and resistance of the membranes were measured [9-15]. It was confirmed that the lipid membranes could discriminate five primary taste substances. Moreover, they could detect the interactions between taste substances observed in biological systems. The response properties were different in different types of lipids. If a hydrophobic part of a lipid was different, taste substances which can be detected were different. These facts indicate that the taste sensor can be realized by the use of various kinds of lipid membranes as transducers. 

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