Acid ether extract

The sodium hydroxide solution should be added slowly, since the reaction with the acidic ether extract is exothermic and may cause boiling of the ether. The ether extract should be washed with aqueous sodium hydroxide until the aqueous layer remains basic to litmus. This extraction is self-indicating the ether turns from a bright yellow to a light brown and color appears in the aqueous phase. 

Acid Ether Extract Add 5 mL of 3 A hydrochloric acid to the extracted colorant solution set aside in the alkaline ether extract procedure above, mix, and extract with ether as directed above. Wash the ether extract with two 25-mL portions of 0.1 N hydrochloric acid and water. Transfer the washed ether in portions to the flask containing the evaporated alkaline extract, and carefully remove all the ether by distillation. Dry the residue in an oven at 85° for 20 min. Then allow the flask... 

Further studies showed that, in fact, two volatile fatty acids present in rumen fiuid were essential for growth of strain Ml (23). One of these was acetate, and relatively large amounts were required for optimal growth. In the complex assay medium indicated above, but containing the residue of acid-ether extracted rumen fiuid, the optimal concentration of acetate was about 16 to 20 mM. Equimolar additions of NaCl or NaHCOa to the medium would not replace acetate. 

From the above-mentioned degradation, UV and 1H-NMR studies, and the bio-genetic considerations, PHM was imagined to have a partial structure containing a thiazoline-thiazole chromophore shown in Fig. 8 in the place of VI in BLM. If PHM has this partial structure, its acid hydrolysis gives 2-acetylthiazole-4-carboxylic acid in addition to /3-alanine (Fig. 8). Actually, 2-acetylthiazole-4-carboxylic acid has been isolated from the acidic ether extract of the acid hydrolyzate of PHM. 

The paraffinic carbon composition is similar for both groups of acid/ether extracted organics as is the presence of mono- and diaromatic compounds. No significant pH effects are observed, although the basic HC1 extract has a lower aromatic content than either the pH 1 or 6.5 fraction. The NMR data for the first bitumen fraction indicate that it is also predominantly paraffinic, in agreement with the earlier results of Spiro. (2 )... 

It was determined that approximately four times more bitumen-free organic matter is associated with silicate minerals than with carbonate minerals. The major structural constituent of the various filtrate fractions was paraffinic compounds. However, spectroscopic analysis indicated relatively larger concentrations of olefins and branched paraffins with the acid/ether extracted... 

The acid-ether extract is shaken with a solution of sodium bicarbonate to remove the strong acids such as aspirin, then with sodium hydroxide solution to remove the weak acids, such as the barbiturates, neutral drugs such as the carbamates, and a few weak bases such as calFeine, remaining in the ether layer. 

The acid ether extract may be subdivided to give the strong acid, weak acid, and neutral fractions as described previously. The method is not particularly satisfactory for bases, but will often given an indication as to what is present. 

Fatty acids / ether extract % of total fatty acids in the ether extract This coefficient can be used to calculate an individual fatty acid content from the percentage of this fatty acid relative to the total fatty acids. 

Acid detergent fibre (%) 5.5 0.9 Fatty acids/ether extract (%) 75 ... 

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