Chloro form

H NMR spectrum of chloro form (HCCI3) Chemical shifts are measured along the X axis in parts per million (ppm) from tetramethylsi lane as the reference which IS assigned a value of zero... 

For twice-distilled material infrared (liquid film) cm." 1745 strong, 1565 strong, 1430 medium strong proton magnetic resonance (chloro-form-d) (number of protons, multiplicity, coupling constant J in Hz) 3.14-3.45 (1, multiplet), 3.76 (3, singlet), 3,86 (3, singlet), 5.6 (1, doublet of doublets, J = 6 and 8). 

Normally, the hydrogenation of a readily hydrogenated double bond occurs over palladium-on-charcoal in ethanol at room temperature and atmospheric pressure. The more difficultly reduced olefins require elevated reaction temperatures and/or pressures for the reaction to proceed at a reasonable rate. The saturation of an 8(14)-double bond is virtually impossible under normal hydrogenation conditions. In order to remove unsaturation at this position it is necessary to first isomerize the double bond to the readily hydrogenated 14 position by treatment with dry hydrogen chloride in chloro-form. ° ... 

Fluorohydrin formation by epoxide opening with hydrogen fluoride in chloro-form-tetrahydrofuran, 435... 

An excellent example of PLC applications in the indirect coupling version is provided by the works of Miwa et al. [12]. These researchers separated eight phospholipid standards and platelet phospholipids from the other lipids on a silica gel plate. The mobile phase was composed of methylacetate-propanol-chloro-form-methanol-0.2% (w/v) potassium chloride (25 30 20 10 10, v/v). After detection with iodine vapor (Figure 9.2), each phospholipid class was scraped off and extracted with 5 ml of methanol. The solvent was removed under a stream of nitrogen, and the fatty acids of each phospholipid class were analyzed (as their hydrazides) by HPLC. The aim of this study was to establish a standardized... 

The consumption of the oxime can be checked by thin-layer chromatography on silica gel G with the solvent system chloro-form/methanol (95/5 v/v) and a spray reagent consisting of 5% potassium dichromate in 40% sulfuric acid. The oxime appears as an immediate dark spot and the aziridine as a yellow spot. The checkers observed identical mobilities (Rf 0.8) for both compounds. 

Mobile phase composition 1 = toluene-ethyl acetate-formic acid (30 10 10, v/v) 2 = toluene-ethyl acetate-formic acid (55 20 25, v/v) 3 = toluene-acetone-formic acid (7 6 1, v/v) 4 = benzene-ethyl acetate-formic acid (30 15 5, v/v) 5 = chloroform-methanol-formic acid (15 3 2, v/v) 6 = chloro-form-methanol-formic acid (147 30 23, v/v) 7 = Toluene-chloroform-acetone-formic acid (8 4 3 3, v/v) 8 = chloroform-methanol-formic acid (37 8 5, v/v) 9 = chloroform-methanol-formic acid (36 9 5, v/v) 10 = ethyl acetate-chloroform-formic acid (24 21 5, v/v) 11 = ethyl acetate-chloro-form-formic acid (23 21 6, v/v). 

Typical procedure A mixture of the benzyl ether (0.246 g, 1 mmol) and p-phe-noxyphenyltellurium trichloride (0.403 g, 1 mmol) in anhydrous chloroform (15 ml) was stirred for 30 min at room temperature, then the solvent was evaporated and the residue was filtered through a column of silica gel eluting with chloroform. Evaporation of the solvent in a rotatory evaporator followed by recrystallization of the residue from chloro-form/petroleum ether and washing several times with petroleum ether gave 0.50 g (97%) of the product, m.p. 108-110°C. 

CCh Chloro- form Di- Pentane Heptane Cyclo- Benzene Toluene chloro- hexane methane ... 

CTAB/chloro- form/ -octanol PeniciUin G >90% extraction was achieved at pH 5-8 and the mechanism of extraction was realized to be ion-pairing electrostatic interactions [300]... 

OCH3 6-Methoxy-3-meth-oxycarbonyl-2-methyl-5-nitro-... 76 180-182 (Chloro- form/ Hexan) ... 

Temper- ature °C Water Alcohol 95% Carbon tetra- chloride Chloro- form Dichloro- ethane Carbon disul- phide Ether... 

Temper- ature °C Chloro- form Methyl acetate Ethyl acetate Cyclo- hexa- none Nitro- benzene Pyridine Mesityl oxide... 

Nous avons pu ainsi calculer la constante K du complex chloro-forme lourd-ether etkylique, complexe etudie en solution dans le tetrachlorure de carbone, et pour lequel la methode classique ne pent etre utilisee [9],... 

LXVI 6-Acetamido- 3-methyl- capronsaure- methylamid 10 20- 2 2 200,3 Chloro- form 0,46 25 589 +24,57... 

LXXIX (R)-Citronellal- diathylacetal CuPuP 228,4 Chloro- form 0,1168 25 589 +4,91 ... 

LXXXI (+)(R)-6-Meth- oxy-4-methyl- hexanal-di- athylacetal c12h26o3 218,3 Chloro- form 0,0962 25 589 +3,78 ... 

LXXVIII a (R)-3,7-Di- methyl- octanal-di- vinylacetal l34h26u2 226,4 Chloro- form 10,703 26 589 + 3,04 ... 

LXXVIII b (R) -2 [2,6-Dime-thyl-lieptyl]-1,3-dioxan LigHggUg 214,3 Chloro- form 19,298 25 589 +2,48 ... 

Procedures for isolation and measurement of lipids in foods include exhaustive Soxhlet extraction with hexane or petroleum ether (AOAC, 1995 see Basic Protocol 1), chloro-form/methanol (Hanson and Olley, 1963 Ambrose, 1969), chloroform/methanol/water (Folch et al., 1957 Bligh and Dyer, 1959 see Basic Protocol 2 and Alternate Protocol 2), acid digestion followed by extraction (see Basic Protocol 4), or, for starchy material, extraction with n-propanol-water (e.g., Vasanthan and Hoover, 1992 see Basic Protocol 3). Each method has its own advantages and disadvantages and successful measurement of lipid content is often dictated by the type of sample and extraction medium employed. Commercial extraction and preparation of edible oils are explained in the literature (Williams, 1997). 

For extraction of lipids, using all four protocols, approximately 35 to 40 hr is required. The time required for the Soxhlet method (see Basic Protocol 1) is up to 12 hr, the chloro-form/methanol/water extraction (Basic Protocol 2), up to 12 hr, n-propanol/water extraction (see Basic Protocol 3), 5 to 6 hr, and extraction of lipids requiring acid digestion (see Basic Protocol 4), 5 to 8 hr. 

It is important to keep the solvent ratio as close as possible to 8 4 3 (v/v/v) chloro-form/methanol/water, to prevent selective loss of lipid classes during this step (Christie, 1989a). Therefore, it is necessary to estimate the water content of the lipid sample before extraction and take this into consideration when determining the amount of 0.88% KCl needed. In addition, during filtration, a portion of the organic solution is lost due to evaporation directly from the funnel, increasing with filtration time. One should try to estimate the loss and adjust the volume of the 0.88% KCl based on empirical observation for a specific type of sample. 

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