摘要:

A reasonably simple procedure for determining the concentration of heavy water solutions, based on the comparison of the vapor pressures of these solutions with pure water, has been developed. The method is useful for samples as small as 0.5 mgm. and the sample may be recovered. Individual determinations require about two hours. In the work reported, mean determinations did not vary from the best curve through the experimental points by more than 0.2 mole % of D2O, while the spread in any group of readings was about ±0.25 mole %.

ISSN:1923-4287    

DOI:10.1139/cjr49b-001

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

A procedure has been developed for the estimation of butyric, acetic, formic, succinic, and lactic acids in fermentation solutions. The acids are extracted by ether, separated by partition chromatography on a column of silica gel using benzene–butanol mixtures, and each determined quantitatively by titration with 0.01 Nsodium hydroxide using phenol red as indicator. Recoveries are quantitative and determinations accurate within ± 2%. A method is also given for the quantitative separation and estimation of butyric, propionic, acetic, and formic acids, as well as a modified procedure for preparation of silica suitable for partition chromatography.

ISSN:1923-4287    

DOI:10.1139/cjr49b-002

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr49b-003

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

The isopiestic method has been applied to the testing of activated charcoals. The ratios of vapor adsorbed at saturation were found to agree well with the ratios of the activities obtained by a flow method. The sorptive capacities of nine different activated charcoals for carbon tetrachloride water, amyl chloride, benzene, methyl alcohol,n-hexane, mustard gas, and phosgene have been compared. A simple, rapid method for testing charcoals is suggested.

ISSN:1923-4287    

DOI:10.1139/cjr49b-004

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Natural sources ofcis-n-eicos-11-enoic acid, a convenient method of isolating the acid, and its conversion to thetrans-form are described. It was found that the principal eicosenoic acid of a sample of Atlantic cod liver oil (Gadus callarias) was the Δ11isomer, in contrast to the reports of other workers who investigated Pacific codfish and found only the Δ9isomer. The following derivatives are reported:cis-n-eicos-11-enoic anilide, N-hydroxyamide, epoxide, chlorohydrin; 11,12-dihydroxyeicosanoic acid (low-melting isomer), and its amide;trans-n-eicos-11-enoic acid, its hydrazide, and N-hydroxyamide. Some new physical constants of thecis-acid and its methyl ester are given.

ISSN:1923-4287    

DOI:10.1139/cjr49b-005

出版商:NRC Research Press    

年代:1949

数据来源: NRC