Methylene chloride acetone solvent

The solvent used to form the dope is evaporated during the extrusion process and must be recovered. This is usually done by adsorption on activated carbon or condensation by refrigeration. For final purification, the solvent is distilled. Approximately 3 kg of acetone, over 99%, is recovered per kg of acetate yam produced. Recovery of solvent from triacetate extmsion is similar, but ca 4 kg of methylene chloride solvent is needed per kg of triacetate yam extmded. 

No. Modifying Agent Chloroform Methylene Chloride Solvent DMF DMSO DMAC THF Acetone... 

Another approach to processable bismaleimide resins via Michael addition chain extension, is the reaction of bismaleimide, or a low melting mixture of bismaleimides, with aminobenzoic hydrazide to provide a resin which is soluble in various solvents, such as acetone, methylene chloride and DMF (49). The idealized chemical structure for a 2 1 BMI-aminobenzoic hydrazide resin is... 

A mixture of 290 mg of the 16,21-diacetate of 6a,9a-difluoro-16a-hydroxy-hydrocortisone, 30 cc of t-butanol, 0.5 cc of pyridine and 150 mg of selenium dioxide was refluxed for 53 hours under an atmosphere of nitrogen and cooled ethyl acetate was added and filtered through celite the solvent was evaporated to dryness under reduced pressure, the residue was triturated with water, the solid was collected by filtration, washed with water and dried. The product was then chromatographed on 10 grams of silica gel. The solid fractions eluted with acetone-methylene chloride (1 19) were recrystallized from methylene chloride, thus affording 68 mg of the 16,21-diacetate of 6a,9a-difluoro-16a-hydroxy-prednisolone MP 212° to 215°C. 

Some experiments show traces of acetone, methylene chloride, chloroform, benzene, and dioxane in the air. Only in one instance (chloroform) was a TLV exceeded. However, pump error may have caused this result. When many solvents or air contaminants coexist in the environment, a total or equivalent exposure must be calculated. The equivalent exposure reflects the contribution of each contaminant to the total exposure. In these studies this value was very low and can be noted in the next to last column of Table II. Solvents like benzene, chloroform, and dioxane are presently suspected carcinogens (j>) and laboratory instructors should replace these compounds with safe substitutes whenever possible. 

The nonhygroscopic compound is found to be very stable and very insoluble, even with boiling, in common solvents such as water, acetone, methylene chloride, hexane, and acetonitrile. However, the compound is found to be soluble in a stoichiometric amount of aqueous potassium hydroxide, in which the 3ip nmr spectrum shows a sharp singlet at —29.3 ppm relative to 85% phosphoric acid. 

With a twofold to threefold excess in trifluoroacetic anhydride, reaction (1) is quantitative within 1 day at room temperature. The A-trifluoroacetylated polyamides (NTFA-PA) are soluble in many ordinary organic solvents, such as acetone, methylene chloride, chloroform, and tetrahydrofuran. In addition to the... 

This class of protic ionic liquids resulted miscible with polar molecular solvents such as acetonitrile, acetone, methylene chloride and ethyl acetate, remaining immiscible with hydrocarbon solvents. Two different applications have been reported by the same authors as solvents in the Heck reaction and as supports for homogeneous supported-phase synthesis. 

When trace quantities of materials are extracted, it is necessary to evaporate most of the solvent to concentrate the desired compound for further analysis. This can be difficult to do without losing the desired compound as well. The two most common ways of removing large volumes of solvent without appreciable loss of the desired compound are a Kudema-Danish concentrator and a rotary evaporator. The former is preferred for low-boiling solvents (< 100 "C, acetonitrile, acetone, methylene chloride), and the latter for higher-boiling solvents. A Kuderna-Danish concentrator is shown in Figure 9-6. 

Eight micro liter of octane extraction solvent was placed inside a porous, polypropylene fiber following an 8 min analyte preconcentration step, 4 fil of extract was injected into a gas chromatograph Static subcritical water extraction was coupled with styrene-DVB (SDB-XC) extraction discs soil, water, and the SDB-XC disc are placed in a sealed extraction cell, heated to 250°C for 15 to 60 min, cooled, and the PAHs recovered from the disc with acetone/methylene chloride With a Soxhlet apparatus (18 h), by PLE (50 min at 100°C), SEE (1 h at 150°C with pure CO2), and subcritical water (1 h at 250°C, or 30 min at 300°C)... 

Handling of the dry samples usually requires the addition of water to moisten the sample, along with the organic solvents. Sonication of the blended mixture expedites the extraction of target compounds. However, it is not recommended for OPs fSW-846 method 8141A U.S. Environmental Protection Agency (EPA, 1994)]. Acetone, methylene chloride, hexane, petroleum ether, acetonitrile, and methanol are some of the. solvents used for extraction of pesticides depending on the sample matrix and the nature of the pe.sticidc(s). 

Isohexane Methylcyclopentane solvent, extraction fats/oils Perchloroethylene Trichloroethylene solvent, extraction food Acetone Alcohol Ethyl acetate Ethylene dichloride Methyl alcohol Methylene chloride solvent, extraction food processing Methyl ethyl ketone solvent, extraction fragrances Methyl carbonate solvent, extraction hops extract Hexane Methyl alcohol Methylene chloride solvent, extraction hydrocarbon Acetonitrile... 

Solubility in solvents at20°C chloroform, acetone methylene chloride, ethyl acetate, toluene... 

Note to the instructor Possible pairs of compounds are given in the following list. The two compounds to be resolved are given first, followed by the three developing solvents to try (1) benzoin and benzil acetone, methylene chloride, hexane (2) vanillin and vanillyl alcohol acetone, 50% toluene-50% ethyl acetate, hexane (3) diphenylmethanol and benzophenone acetone, 70% hexane-30% acetone, hexane. Each compound in a pair should be prepared individually and as a mixture of the two compounds. Prepare all of them as 1% solutions in acetone. 

Sephadex LH-20 has been developed for nonaqueous solvents. Some of the hydroxyl groups have been alkylated, and thus the material can swell under both aqueous and nonaqueous conditions (it now has "organic" character). This material can be used with several organic solvents, such as alcohol, acetone, methylene chloride, and aromatic hydrocarbons. 

Figure 2. (A) Composite TLC of phytotoxins from root extracts of sorghum on normal silica gel plate showing elution of 1 - 10, developing solvent hexane isopropyl alcohol (90 10) (B) representative TLC of congeners of on silica gel impregnated with 5% AgNOs showing separation of 1, and 4-7, developing solvent hexane acetone methylene chloride (7 2 1). O, origin SF, solvent front.

To reduce the possibility of solute-solvent interaction non-polar solvents should be used. This is not always practicable and the more common solvents are carbon disulphide, chloroform, carbon tetrachloride and acetone. Methylene chloride, bromoform, dimethylformamide and pyridine are less commonly used. All organic materials have infra-red absorption and no solvent is completely transparent it is usual therefore to select one... 

Ultrasonic degreasing is known to produce excellent results for small components. Trichloroethylene, acetone, methylene chloride, tetrachloroethylene, and so on are among good solvents for ultrasonic degreasing. Alcohol, gasoline, and paint thinners are not recommended. An effective solvent is 1,1,1-tri-chloroethane because of its low toxicity and flammability. To verify the cleanliness of a surface that has been degreased, water or dyne liquids are used. If a drop of water forms a film of the surface, then it is free from contamination. If a drop retains its shape, degreasing of the surface must be repeated. 

Stabaxol I is soluble in selected organic solvents such as acetone, methylene chloride, toluene, and polyester. 

Chemicals and solvents used in biological manufacturing include alcohol, acetone, methylene chloride and numerous other aggressive materials. Filters required for chemical and solvent filtration include coarse prefllters, line prefillers, membrane prefllters, final sterile filters and tank vent filters. 

Selection of solvents. The choice of solvent will naturally depend in the first place upon the solubility relations of the substance. If this is already in solution, for example, as an extract, it is usually evaporated to dryness under reduced pressure and then dissolved in a suitable medium the solution must be dilute since crystallisation in the column must be avoided. The solvents generally employed possess boiling points between 40° and 85°. The most widely used medium is light petroleum (b.p. not above 80°) others are cycZohexane, carbon disulphide, benzene, chloroform, carbon tetrachloride, methylene chloride, ethyl acetate, ethyl alcohol, acetone, ether and acetic acid. 

CeUulose triacetate is insoluble in acetone, and other solvent systems are used for dry extmsion, such as chlorinated hydrocarbons (eg, methylene chloride), methyl acetate, acetic acid, dimethylformamide, and dimethyl sulfoxide. Methylene chloride containing 5—15% methanol or ethanol is most often employed. Concerns with the oral toxicity of methylene chloride have led to the recent termination of the only triacetate fiber preparation faciHty in the United States, although manufacture stiH exists elsewhere in the world (49). 

Although most of the installed solvent dehydration systems have been for ethanol dehydration, dehydration of other solvents including 2-propanol, ethylene glycol, acetone, and methylene chloride, has been considered. 

Solubility and Solvent Resistance. The majority of polycarbonates are prepared in methylene chloride solution. Chloroform, i7j -l,2-dichloroethylene, yy -tetrachloroethane, and methylene chloride are the preferred solvents for polycarbonates. The polymer is soluble in chlorobenzene or o-dichlorobenzene when warm, but crystallization may occur at lower temperatures. Methylene chloride is most commonly used because of the high solubiUty of the polymer (350 g/L at 25°C), and because this solvent has low flammabiUty and toxicity. Nonhalogenated solvents include tetrahydrofuran, dioxane, pyridine, and cresols. Hydrocarbons (qv) and aUphatic alcohols, esters (see Esters, organic), or ketones (qv) do not dissolve polycarbonates. Acetone (qv) promotes rapid crystallization of the normally amorphous polymer, and causes catastrophic failure of stressed polycarbonate parts. 

Stability. Avermectins are highly lipophilic substances and dissolve in most organic solvents such as chloroform, methylene chloride, acetone, alcohols, toluene, cyclohexane, dimethylformamide, dimethyl sulfoxide, and tetrahydrofiiran. Thek solubiUty in water is correspondingly low, only 0.006-0.009 ppm (= mg/L). 

The physical properties of methylene chloride are Hsted in Table 1 and the binary a2eotropes in Table 2. Methylene chloride is a volatile Hquid. Although methylene chloride is only slightly soluble in water, it is completely miscible with other grades of chlorinated solvents, diethyl ether, and ethyl alcohol. It dissolves in most other common organic solvents. Methylene chloride is also an excellent solvent for many resins, waxes, and fats, and hence is well suited to a wide variety of industrial uses. Methylene chloride alone exhibits no dash or fire point. However, as Htde as 10 vol % acetone or methyl alcohol is capable of producing a dash point. 

Paprika oleoresin (EEC No. E 160c) is the combination of davor and color principles obtained by extracting paprika with any one or a combination of approved solvents acetone, ethyl alcohol, ethylene dichloride, hexane, isopropyl alcohol, methyl alcohol, methylene chloride, and trichloroethylene. Depending on their source, paprika oleoresins are brown—red, slightly viscous, homogeneous Hquids, pourable at room temperature, and containing 2—5% sediment. 

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