摘要:

AbstractImpure iron oxide, which is a by‐product in the extraction of alumina from bauxite, is valueless as an absorbent for hydrogen sulphide. Attempts to activate the waste oxide by simple chemical treatments were unsuccessful. Partial reduction in coal gas, followed by oxidation with air, gave three groups of oxides showing high activity, high capacity and rapid revivability. Study of the absorption and reactivation reactions showed that sulphidation occurred in two stages: first, a rapid logarithmic reaction, followed by a slower autocatalytic absorption. If the reaction were stopped on completion of the first stage, and the material then revivified, the resultant oxide showed the second autocatalytic stage. Suggestions for the mechanism of the changes involved are advanced.The activated oxide was shown to be better than all of a number of commercial absorbents examined, except for bog ore admixed with peat, and even with this high‐grade material the comparison was not too unfavoura

ISSN:0368-4075    

DOI:10.1002/jctb.5000650801

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractA new design of apparatus for analyses involving the quantitative distillation of ammonia, e.g., in the Devarda procedure, it described. To remove entrained non‐volatile alkali from the vapour, the latter is passed through water at the boiling‐point in a special scrubber. Strict tests, which have been made by reducing samples of a nitric, acid solution and titrating the resultant asonia with the same nitric solution, have demonstrated the quantitative reliability of the appara

ISSN:0368-4075    

DOI:10.1002/jctb.5000650802

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractThis survey of the changes in the analytical values of meat during cooking was undertaken in order to contribute towards an explanation of the changes in nutritive value, flavour, texture and appearance. A knowledge of these accurately determinable quantities is an essential preliminary to a study, which is contemplated, of the subjective characters enumerated. Some, interesting points of fundamental importance emerge: the nature of the soluble phosphorus compounds in meat, reflecting the degradation of the more complex molecules present in living tissue: the case of hydrolysis of the proteins by acid in the cold, but their relative stability to boiling for 1 hour in aqueous solution; the partial breakdown of the proteins on pressure‐cooking to give amino.acids and peptides; the destruction of creatino or creatinine at 120°c.; and the interesting relation, ships between concentration of protein and change in pH due to coagulation by he

ISSN:0368-4075    

DOI:10.1002/jctb.5000650803

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractThe writer has adapted the Dead‐Stop End Point method of titration evolved by C. W. Foulk and A. T. Bawden in 1926 to the volumetric estimation of reducing sugars with Fehling's Solution without previous clarification of the sugar solutions. The end point is detected by the polarization effect at two plain copper electrodes dipping into the solution being titrated, to which an E.M.F. of 10 millivolts is applied. With impure sugar solutions, the impurities act as depolarizing agents, but the writer has overcome this effect by adding 0.3 gram of purified animal charcoal to the solution at the start of the titration. A number of examples is give

ISSN:0368-4075    

DOI:10.1002/jctb.5000650804

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractNew specific or very selective organic reagents are described: acid solutions of thionine for thiosulphates; acid solutions of α‐diketones for ureas, guanidines and nitrates, and mineral acid solutions of resorcinol for nitroso compounds. The resorcinol sugar reaction being interfered with by nitrates and nitrites, attention is drawn to hydrochloric acid solutions of urea and tryptophane for the detection of carbohydrates. New reactions of anionic and cationic wetting agents for earth alkalis and metal acids (e.g. of molybdenum and tungsten) respectively show again the analytical value of soaps and wetting agents. Instead of wetting agents special preparations of anionic and cationic “gelatines” may be of value. ϵ‐Bensylthiuronium chloride in hot ammoniacal solutions, i. e. benzyl mercaptan, was found to be a sensitive and very selective cobalt and nicke

ISSN:0368-4075    

DOI:10.1002/jctb.5000650805

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractThe baking quality, germination vitality and phosphatase activity of a wheat were examined after heat treatment at moisture contents ranging from 5.5 to 35%. Curves relating the percentage of phosphatase inactivation to temperature of treatment are presented. The correlation between phosphatase inactivation and damage to either vitality or baking quality varies with moisture content and is less than that between vitality and baking quality in the important region above 15% moisture. The detection and uset of an ezyme system of greater heat lability than phosphatase is desirable for the unequivocal diagnosis of mild damage to either vitality or baking quality of wheat.

ISSN:0368-4075    

DOI:10.1002/jctb.5000650806

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractThe extraction method for the purification and concentration of penicillin is reviewed. The theoretical basis underlying the extraction process is examined. A simple distribution formula reproduces the results well and in used to examine the dependence of the selectivity of a solvent on pH of extraction. A number of solvents were tested, most of them show better solvent power for penicillin than the widely‐used amyl acetate. Outstanding amongst these solvents are the cyclic ketones such as methylcyclo‐hexanone and dimethylcyclohexanone.* With these solvents efficient extraction at pH4 is possible, thus avoiding contact of penicillin with solutions of greater acidity where it becomes unstable. The selectivity of these solvents is examined and found to increase with the pH of extraction. At pH4 the selectivity of methylcyclobexanone approached that of chloroform, the latter being a very selective solvent for penicil

ISSN:0368-4075    

DOI:10.1002/jctb.5000650807

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY