Glycerol solutions

On rapid heating, oxaUc acid decomposes to formic acid, carbon monoxide, carbon dioxide, and water (qv). When it is heated ia 96 wt % glycerol solution at 88—121°C, the presence of formic acid ia the decomposed product tends to accelerate the decomposition reaction. Formic acid is thus... 

The solubihty of the Rhovanil vanillin in water—ethanol, water—propylene glycol, and water—glycerol solutions are shown in Eigure 1. In addition, the influence of temperature and solvent concentration are important in maximizing the vanillin concentration. 

Fig. 1. Solubility of vanillin in (a) ethanol solutions, (b) propylene glycol solutions, and (c) glycerol solutions, where A is 40°C B, 30°C C, 20°C D, 10°C ...

Op into aqueous glycerol solutions. Op into aqueous millet jelly solutions. Same definitions as 5-26-M. 

The strong interactions between the water molecules also become obvious from NMR measurements by Tsujii et al..57) 13C-NMR experiments were used for determining the microviscosity of water in reversed micelles of dodecylammonium-propionate with 13C glycine cosolubilized. It was found that the apparent viscosity of the water-pool corresponds to the viscosity of a 78 % aqueous glycerol solution, obviously as a consequence of the extended network formation by strong hydrogen bonding. 

Where membrane storage is required after cleaning, a 5% glycerol solution containing 0.5 to 1.0% weightformaldehyde often is employed. The membranes should be totally immersed, with all inlet and outlet valves closed. This solution should be changed every 30 days. 

Table 3.1 gives a set of pressure versus temperature data of equilibrium C02 hydrate formation conditions that were obtained from a series of experiments in a 20 wt % aqueous glycerol solution. The objective is to fit a function of the form... 

Table 3.1 Incipient Equilibrium Data on CO2 Hydrate Formation in 20 (wt%) Aqueous Glycerol Solutions...

Brelland, E. and P. Englezos, "Equilibrium Hydrate Formation Data for carbon Dioxide in Aqueous Glycerol Solutions", J. Chem. Eng. Data, 41, 11-13 (1996). 

Wronski [55] described a method to separate and resolve penicillamine from physiological fluids. To urine (100 mL) was added 60 g of (NH4)2S04, the solution was filtered, mixed with 2 g of Na2S03, and 1 mL of 0.1 M EDTA in 20% triethanolamine, and shaken with 5-20 mL of 0.01-0.06 M tributyltin hydroxide in octane for 5 min. A portion (5-8 mL) of the organic phase was shaken with 0.2 mL of HC1 in 20% glycerol solution. A portion of the aqueous phase (5-10 pL per cm of the strip width) was applied to cellulose gel, and electrophoretic separation was performed by the technique described previously. The thiol spots were visualized with o-hydroxymercuri benzoic acid-dithiofluorescein and densitometry with a 588-nm filter. 

Photosensitization of diaryliodonium salts by anthracene occurs by a photoredox reaction in which an electron is transferred from an excited singlet or triplet state of the anthracene to the diaryliodonium initiator.13"15,17 The lifetimes of the anthracene singlet and triplet states are on the order of nanoseconds and microseconds respectively, and the bimolecular electron transfer reactions between the anthracene and the initiator are limited by the rate of diffusion of reactants, which in turn depends upon the system viscosity. In this contribution, we have studied the effects of viscosity on the rate of the photosensitization reaction of diaryliodonium salts by anthracene. Using steady-state fluorescence spectroscopy, we have characterized the photosensitization rate in propanol/glycerol solutions of varying viscosities. The results were analyzed using numerical solutions of the photophysical kinetic equations in conjunction with the mathematical relationships provided by the Smoluchowski16 theory for the rate constants of the diffusion-controlled bimolecular reactions. 

Glycerol is a non-insulin-dependent source of carbohydrate that can be used to avoid stress-related hyperglycemia in critically ill patients. A major disadvantage of the available glycerol solution is the dilute concentration... 

The non equilibrium status can be seen during a slow cooling of a water-glycerine solution Starting with a 20 % glycerol solution pure ice crystals will first be formed until at -46.5 °C when the glycerol concentration has reached 66.7 %. At this temperature, the eutectic should solidify. Howevere it is possible to reduce the temperature to -58 °C with a glycerol concentration of 73 %. A further decrease of the temperature does not crystallize... 

Fast librational motions of the fluorophore within the solvation shell should also be consideredd). The estimated characteristic time for perylene in paraffin is about 1 ps, which is not detectable by time-resolved anisotropy decay measurement. An apparent value of the emission anisotropy is thus measured, which is smaller than in the absence of libration. Such an explanation is consistent with the fact that fluorescein bound to a large molecule (e.g. polyacrylamide or monoglucoronide) exhibits a larger limiting anisotropy than free fluorescein in aqueous glycerolic solutions. However, the absorption and fluorescence spectra are different for free and bound fluorescein the question then arises as to whether r0 could be an intrinsic property of the fluorophore. 

The known information regarding the influence of various factors is given below. Most of the investigators have tried to study the effect of one variable at a time, but often minor variations of other variables also occur alongside. For example, variation of viscosity by the use of glycerol solution varies the surface tension by a few dynes per centimeter. 

The above equations were verified by using aqueous glycerol solutions (D8). The model gives results which agree reasonably well with the experimental data. 

Todd, P.J. Solution Chemistry and Secondary Ion Emission From Amine-Glycerol Solutions. J. Am. Soc. Mass Spectrom. 

The plates were incubated for 8 days at 28 °C. Then Tween-glycerol solution (7 mL) was filled onto each plate and the spores/mycehum were suspended by rigorous scraping of the agar surface again with a sterile plastic L-shaped spreader. The spore/mycehum suspension was stored in two sterile 50 mL polypropylene tubes at —80 °C until use. 

Figure Y shows the H NMRD profiles of water solutions of Fe(H20)g in 1 M perchloric acid at 298 K and in a glyceroTwater mixture (36). Only one dispersion is observed at about Y MHz. It corresponds to a correlation time Tc 3 X 10 s. The small increase of relaxivity above 20 MHz indicates that a field dependent is influential in the determination of at high field (see also Section II. C). From the fit to the SBM theory, is estimated to be around 5 x 10 s at room temperature, a value commonly found for small complexes in water solution and of the order expected for the mean lifetime between collisions with solvent molecules. The fit also provides a value for A = 0.095 cm , so that t o is calculated to be 9 x 10 s at room temperature. By increasing the viscosity through glycerol water mixture, it is shown that the relative influence of tb on with respect to becomes lower and lower with the increase in relaxivity in the high-field region being more and more evident. The fit of the profile acquired in the glycerol solution, performed by assuming that r, Ag, and A are not affected by the presence...

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