FATTY ACIDS AND THEIR ESTERS: III. IODINE VALUES BY THE BROMINE VAPOR METHOD

1936 ◽  
Vol 14b (6) ◽  
pp. 237-242 ◽  
Author(s):  
H. N. Brocklesby ◽  
K. F. Harding
Keyword(s):  
Fatty Acids ◽  
Iodine Value ◽  
Close Agreement ◽  
Wijs Method ◽  
Iodine Values ◽  
Bromine Vapor ◽  
Value Determination ◽  
Vapor Method

A modified bromine vapor method for iodine value determination that allows of the determination of substitution is described. For non-conjugated unsaturated oils free from oxidation or polymerization products, values are obtained that are in close agreement with those found by Wijs' method. The unsaturation of conjugated esters can be determined satisfactorily. Owing to substitution, the unsaturation of oxidized or polymerized esters cannot be determined by this method.

scholarly journals Analysis of physical, mechanical and chemical properties of seeds and kernels of Jatropha curcas  

2016 ◽  
Vol 61 (No. 3) ◽  
pp. 99-105 ◽  
Author(s):  
M. Müller ◽  
Š. Horníčková ◽  
P. Hrabě ◽  
J. Mařík
Keyword(s):  
Fatty Acids ◽  
Vitamin E ◽  
Jatropha Curcas ◽  
Unsaturated Fatty Acids ◽  
Chemical Properties ◽  
Acid Value ◽  
Chromatography Method ◽  
Value Determination ◽  
And Chemical Properties

The research was performed to examine the physical, mechanical and chemical properties of seeds and kernels of Jatropha curcas. The test parameters were the dimensions of the seeds and kernels, required energy for oil extraction, determination of fatty acids in the oil by gas chromatography method, determination of the iodine value, determination of the acid value, determination of total polyphenols by the Folin & Ciocault reagent and determination of tocopherols and tocotrienols (vitamin E) by High-performance liquid chromatography. It was ascertained that the size of the seed and kernel varies considerably. Pressing of whole seeds needs more energy (50%) than pressing of kernels. From a chemical point of view it seems to be very appropriate for a production of biofuels. Jatropha curcas contains more polyphenols and vitamin E, which act as antioxidants, than the rape. Due to the low content of unsaturated fatty acids it is chemically suitable to replace the rape-seed oil with Jatropha curcas oil.

Determination of the Iodine Value of Oils and Fats: Summary of Collaborative Study

1994 ◽  
Vol 77 (3) ◽  
pp. 674-676 ◽  
Author(s):  
David Firestone
Keyword(s):  
Acetic Acid ◽  
Iodine Value ◽  
Collaborative Study ◽  
Solvent Mixture ◽  
Acid Mixture ◽  
Collaborative Studies ◽  
Wide Range ◽  
Aoac Method ◽  
Iodine Values

Abstract Two collaborative studies were conducted using the Wijs method for determining the iodine value in a wide range of vegetable and animal oils and fats. The results obtained when using carbon tetrachlo-ride were compared to those obtained when using a substitute solvent mixture of cyclohexane and glacial acetic acid. The values reported for the iodine values indicate that the cyclohexane and acetic acid mixture can be used in place of carbon tetrachloride without loss of precision. The method has been adopted first action by AOAC INTERNATIONAL as an IUPAC/AOCS/AOAC method.

Determination of iodine value fatty acids by a flow-injection method

1984 ◽  
Vol 158 ◽  
pp. 157-167 ◽  
Author(s):  
Cheng-chih Lee ◽  
Bruce D. Pollard
Keyword(s):  
Fatty Acids ◽  
Iodine Value ◽  
Flow Injection ◽  
Injection Method

631. Variations in iodine value of milk fats

1956 ◽  
Vol 23 (2) ◽  
pp. 238-247 ◽  
Author(s):  
J. W. Mayhead ◽  
C. R. Barnicoat
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Iodine Value ◽  
Milk Fat ◽  
The Body ◽  
Oleic Acid Content ◽  
Stage Of Lactation ◽  
Breed Differences ◽  
Iodine Values ◽  
Long Chain

Iodine values of milk fats of grazing cows show wide variations which are chiefly determined by differences in oleic acid content. Among the factors promoting the variations are: individuality of the cow, stage of lactation, breed differences, diurnal and incidental (irregular) day-to-day effects, nature of the food and plane of nutrition.Results of experiments with feeding an unsaturated vegetable oil indicate that considerable proportions of the unsaturated long chain acids of milk fat were derived from the ingested oil. It is deduced that herbage lipids may contribute materially to the production of milk fat of grazing cows.From comparisons of the extents to which dietary long chain unsaturated acids are incorporated into milk fats of grazing and semi-fasting cows, it would appear that the rise in iodine value following partial inanition does not result from increased uptake of fatty acids withdrawn from the more highly unsaturated glycerides of the body reserves.

scholarly journals On the Determination of Iodine Value by the Wijs' Method

1975 ◽  
Vol 24 (12) ◽  
pp. 876-878
Author(s):  
Shin-ichi KIKUNO ◽  
Yukinobu MURASE ◽  
Shouji MARUZENI ◽  
Minoru OKAMOTO
Keyword(s):  
Iodine Value ◽  
Wijs Method

The Dissolution of Vulcanized Rubbers and Its Bearing on Problems of Rubber Analysis

1954 ◽  
Vol 27 (2) ◽  
pp. 535-541
Author(s):  
W. C. Wake
Keyword(s):  
Iodine Value ◽  
Transmission Spectra ◽  
Infrared Transmission ◽  
Roller Mill ◽  
Vulcanized Rubber ◽  
Synthetic Rubber ◽  
Determining Factors ◽  
Analytical Procedures ◽  
Value Determination

Abstract Dissolution of a sample of vulcanized rubber is a necessary preliminary to several analytical procedures, e.g., the determination of iodine value or total fillers. If an infallible and convenient agent were available for this process, then doubtless other analytical procedures would be possible of development or improvement and examination of infrared transmission spectra of vulcanized samples would prove a feasible means of identification. Although decalin and nitrobenzene have been widely and satisfactorily used for natural rubber (polyisoprene), there have been several references in the literature to difficulties encountered with the most widely used synthetic rubber, GR-S. Devices to overcome these difficulties include comminution on a roller mill, swelling the sample in strong swelling agents before transferring to the solvent to be used for the dissolution, and grinding on a rubber mill with a plasticizer. All these must be regarded as being of the nature of palliatives, knowledge of the nature of the dissolution process being the real need before the best condition for carrying it out can be decided on. It is shown in this paper that the process is essentially oxidative in nature and, provided that the solvent and rubber are miscible at the temperature of the dissolution, temperature and efficient aeration are the most important rate-determining factors. The nature of the solvent is, of course, of importance with respect to the analytic procedure attempted as all solvents are not suitable for iodine value determination.

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