Organic liquids methanol

In order to obtain any temperature between + 40°C and — 80°C, to induce heating cooling cycles with precision and sufficient flexibility, and to avoid temperature variation and unequal temperature distribution in the samples, special devices were built. These consist of three main parts (1) a cryogenic temperature-production unit capable of delivering either cooled nitrogen gas or cooled organic liquid (methanol) (2) a temperature-regulation device and (3) special ther-mostatted, double-walled measurement cells, as well as cell holders adapted to each particular type of determination. These various devices will be described in detail in Section III. 

Air-organic liquids (methanol, ethanol, n-butanol, ethyl acetate, glycol, methy lethy Iketone, C2H4CI2)... 

A student studies the In P versus /T plots for two organic liquids methanol (CH3OH) and dimethyl ether (CH3OCH3), such as those shown in Figure 11.36. 

No mechanism for cracking in N2O4 has been established . In organic media crack velocities are similar to those obtained in distilled water. Lowering the water content results in lower velocities. Not all authors attribute failures in organic liquids to the residual moisture . Furthermore, part of the fracture may be transgranular . Water additions to methanol increase crack velocities as do halide additions. In oils velocities are similar to those in organic liquids and distilled water. 

It is difficult to estimate the magnitude of the error due to insufficiently low humidity when distillation methods are used with organic liquids such as toluene (6, 28), xylene (6, 28), or chloroform (12). With organic liquids essentially immiscible with water and of high boiling point the error is probably very small. When methanol is used as an extraction solvent, as in the Fischer reagent method, the amount of unextracted water is undoubtedly some function of the concentration of water in the alcohol, but the error might be small because of substitution of adsorbed water by adsorbed alcohol (23, 34). This seems to be borne out by experiments of Schroeder and Nair (31), who deliberately added water to the alcohol to form a 0.5% water solution and found that the results of their moisture determinations were essentially the same as with anhydrous methanol, which contained about 0.05% water. 

Structure of luciferin (Ohtsuka et al., 1976). The luciferin of Diplocardia longa is a colorless liquid, and fairly stable at room temperature. It is soluble in polar organic solvents (methanol, ethanol, acetone, and methyl acetate) but insoluble in nonpolar solvents like hexane and carbon tetrachloride. Based on the chemical properties and spectroscopic data, the following chemical structure was assigned to the luciferin. 

Obtain samples of the following 11 organic liquids contained in individual small dropper bottles n-hexane (or other alkane), acetonitrile, methylene chloride, acetone, toluene, methanol, diethyl ether, ethyl acetate, ethylbenzene, ethanol, and chloroform. Then label each of the test tubes from step 1 with the names, or an abbreviation of the names, of these liquids. 

A few LNG spill tests on organic liquids carried out at Conoco by Yang (1973) led to reproducible explosions. When saturated hydrocarbons from Cj through Cg (including many isomers) were used, immediate explosions were noted. Delays of 5 sec or longer were recorded before they occurred on methanol, acetone, or methyl ethyl ketone. Few or none were recorded for higher alcohols or for hydrocarbons above Cg (or benzene). 

Figure 7. SFE of coal gasification wastewater organics extracted from "Empore" discs using pure C02 (Figure 7a) followed by a second extraction of the same disc with liquid methanol for 16 hours (Figure 7b). The SFE extract obtained using methanol-modified...

The organic liquids in Table 1 include ethanol (ethyl alcohol), which is a common solvent and chemical reagent. During normal exposure in the laboratory such a small amount of ethanol is inhaled or absorbed through the skin that it would correspond to only a miniscule taste of the liquid. However, denaturants in "lab alcohol" can modify its toxicity. Denatured alcohol often contains about 5% of an additive such as benzene or methanol. Of the twenty lab manuals examined, eighteen use ethanol. The other two specified methanol instead. In general, methanol is considerably more toxic than ethanol. 

Variation of the fluorine-19 chemical shift on association has been used to determine solvent effects and basicities28. Muller29 has examined the chemical shifts of 6,6,6-trifluoro-l-hexanol (TFH) in mixtures of water and organic liquids such as acetone, dioxane, THF, ethylene glycol, 2-methoxyethane, 1,2-dimethoxyethane, methanol, r-butanol, dimethyl-formamide and dimethyl sulphoxide. Typical plots are shown in Figures 2 and 3. Solvents... 

It was estimated that the chemicals stored in the room on the mezzanine fell down and and broke, releasing strong acids which then generated heat. When ethanol, methanol, benzene, and other flammable organic liquids mixed in, they caught fire. The chemicals stored there at that time were reported and are listed in Table 2.5... 

Supercritical fluid extraction(SFE) combined with five types of bioassay tests is extensively applied to explore some bioactive substances from thirty types of natural resources available in Korean peninsula. To evaluate comparatively the economic viability of the SFE, organic liquid solvent extraction(LSE) with n-hexane, chloroform and methanol was also performed. To characterize the extracts, GC and HPLC are employed. Also, the column chromatography is used to isolate some target compounds from the total extracts. For all the samples, the optimum SFE condition for each sample which gives maximum yield and cytotoxicity were discussed. 

To figure out comparatively whether the SFE is advantageous or not, the traditional Soxhlet organic liquid solvent extraction(LSE) with n-hexane, chloroform and methanol was carried out. Also, simple but reliable in vitro bioactivity tests were established and applied to the extracts. The bioassays... 

As noted earlier, treatment of C3S pastes with methanol leaves some of the latter strongly sorbed. The methanol is only removable on heating at temperatures at which it reacts with the C-S-H, causing carbonaiion. Flowever, the total weight of volatiles retained in a C3S paste that has been soaked in methanol and then pumped for about 1 h with a rotary pump is near to that obtained on equilibration with saturated LiCl H,0 (T14). Methanol treatment can thus be used as a rapid, though approximate, method of determining chemically bound water. Other organic liquids could possibly be used in a similar way. 

Reversed-phase high-performance liquid chromatography (RP-HPLC) is the usual method of choice for the separation of anthocyanins combined with an ultraviolet-visible (UV-Vis) or diode-array detector (DAD)(Hebrero et al., 1988 Hong et ah, 1990). With reversed-phase columns the elution pattern of anthocyanins is mainly dependent on the partition coefficients between the mobile phase and the Cjg stationary phase, and on the polarity of the analytes. The mobile phase consists normally of an aqueous solvent (water/carboxylic acid) and an organic solvent (methanol or acetonitrile/carboxylic acid). Typically the amount of carboxylic acid has been up to 10%, but with the addition of a mass spectrometer as a detector, the amount of acid has been decreased to as low as 1 % with a shift from trifluoroacetic acid to formic acid to prevent quenching of the ionization process that may occur with trifluoroacetic acid. The acidic media allows for the complete displacement of the equilibrium to the fiavylium cation, resulting in better resolution and a characteristic absorbance between 515 and 540 nm. HPLC separation methods, combined with electrochemical or DAD, are effective tools for anthocyanin analysis. The weakness of these detection methods is a lack of structural information and some nonspecificity leading to misattribution of peaks, particularly with electrochemical... 

Most research into the study of dispersion polymerization involves common vinyl monomers such as styrene, (meth)acrylates, and their copolymers with stabilizers like polyvinylpyrrolidone (PVP) [33-40], poly(acrylic acid) (PAA) [18,41],poly(methacrylicacid) [42],or hydroxypropylcellulose (HPC) [43,44] in polar media (usually alcohols). However, dispersion polymerization is also used widely to prepare functional microspheres in different media [45, 46]. Some recent examples of these preparations include the (co-)polymerization of 2-hydroxyethyl methacrylate (HEMA) [47,48],4-vinylpyridine (4VP) [49], glycidyl methacrylate (GMA) [50-53], acrylamide (AAm) [54, 55], chloro-methylstyrene (CMS) [56, 57], vinylpyrrolidone (VPy) [58], Boc-p-amino-styrene (Boc-AMST) [59],andAT-vinylcarbazole (NVC) [60] (Table 1). Dispersion polymerization is usually carried out in organic liquids such as alcohols and cyclohexane, or mixed solvent-nonsolvents such as 2-butanol-toluene, alcohol-toluene, DMF-toluene, DMF-methanol, and ethanol-DMSO. In addition to conventional PVP, PAA, and PHC as dispersant, poly(vinyl methyl ether) (PVME) [54], partially hydrolyzed poly(vinyl alcohol) (hydrolysis=35%) [61], and poly(2-(dimethylamino)ethyl methacrylate-fo-butyl methacrylate)... 

To be referred to next is the most modem diamond anvU type, generating pressures of order of 10 -100 GPa. The cell illustrated in Figure 6(e) consists of two gem diamonds with optically flat surfaces, between which a sample confined in a drilled hole of a thin metal gasket is sandwiched. To attain isostatic compression an inert gas or an organic liquid, like a 4 1 volume mixture of methanol and ethanol, is contained with the sample. The generated pressure is measured directly from the pressure shift of the fluorescence line of mby powder mixed with the sample. Temperatures to 5000 K can be obtained by laser heating. The quantity of sample confined in a typically 0.1-mm-wide hole is extremely small, just a few microcrystals. At present, research has focused on in situ observations using X-ray and other optical methods, rather... 

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