scholarly journals Spectrographic studies on the antimony trichloride reaction for vitamin A

1938 ◽  
Vol 32 (10) ◽  
pp. 1668-1674 ◽  
Author(s):  
Olav Notevarp ◽  
Harald William Weedon
Keyword(s):  
Vitamin A ◽  
Antimony Trichloride

STUDIES ON ANTIOXIDANT ACTIVITY: I. ESTIMATION OF ANTIOXIDANT ACTIVITY IN STABILIZING VITAMIN A IN OILS

1941 ◽  
Vol 19b (1) ◽  
pp. 17-23 ◽  
Author(s):  
W. E. Parker ◽  
A. C. Neish ◽  
W. D. McFarlane
Keyword(s):  
Antioxidant Activity ◽  
Vitamin A ◽  
Wheat Germ ◽  
Chloroform Solution ◽  
Ultra Violet ◽  
Antimony Trichloride ◽  
Direct Application ◽  
Wheat Germ Oil ◽  
Destructive Action ◽  
Antioxidant Potency

The efficiency of wheat-germ oil in stabilizing vitamin A against the destructive action of ultra-violet radiations was investigated. A rapid and convenient method of estimating antioxidant potency is described which is based on ultraviolet irradiation of mixtures of halibut liver oil and antioxidant in chloroform solution and estimation of vitamin A by the direct application of the antimony trichloride reaction employing photoelectric colorimetry.

A STUDY OF THE SUCCESSION OF VISUAL PIGMENTS IN PACIFIC SALMON (ONCORHYNCHUS)

1966 ◽  
Vol 44 (3) ◽  
pp. 429-455 ◽  
Author(s):  
D. D. Beatty
Keyword(s):  
Vitamin A ◽  
Sockeye Salmon ◽  
Pacific Salmon ◽  
Progressive Increase ◽  
Visual Pigments ◽  
Antimony Trichloride ◽  
The Other ◽  
Simple Function ◽  
Partial Bleaching ◽  
Colorimetric Reaction

Retinae of Pacific salmon (Oncorhynchus) have mixtures of two visual pigments, one a retinene1 (VP 5031) and the other a retinene2 pigment (VP 5272). Retinal extracts were prepared from individuals of five species collected at different times of the year. These extracts were subjected to partial bleaching experiments to determine the proportions of the two visual pigments. Liver extracts were prepared and the percentages of vitamin A1 and vitamin A2 were estimated in these extracts by means of the Carr-Price (antimony trichloride) colorimetric reaction. There was a progressive increase in the percentage of VP 5272 in retinae of adult coho, king, pink, chum, and sockeye salmon during the spawning migration. Except for the sockeye salmon, this increase resulted in a conversion from a retina having predominantly VP 5031 to one having a preponderance of VP 5272- Juvenile coho and king salmon exhibited changes in the proportions of the two visual pigments during the year, but similar changes did not occur in juvenile sockeye salmon. The percentage of VP 5272 in the retina is not a simple function of the proportion of vitamin A2 in the liver; however, there was an increase in the percentage of vitamin A2 in the liver of adult salmon which accompanied the increase in the proportion of VP 5272.

Assay of Oil-Soluble Vitamins. Part I. Vitamin A and Carotene: Suggestions for Improving Assay

1964 ◽  
Vol 47 (4) ◽  
pp. 756-762
Author(s):  
M J Deutsch ◽  
S W Jones ◽  
J B Wilkie ◽  
D Duffy ◽  
H W Loy
Keyword(s):  
Vitamin A ◽  
Internal Standard ◽  
Antimony Trichloride ◽  
Commercial Products ◽  
Time Changes

Abstract The adaptation of official methods to the assay of vitamin A in many commercial products has required modifications in the apparatus used and improvements in assay techniques. These modifications increased the number of routine samples that are screened per day from three to eight, with a corresponding increase in per cent recovery and degree of reproducibility. The most important modifications were installation of equipment to permit handling of more samples at a time, changes in volumes and concentrations of solutions to improve separations, and use of an internal standard in the antimony trichloride method for the assay of vitamin A.

ESTIMATION OF THE BIOLOGICAL POTENCY OF VARIOUS FORMS OF VITAMIN A

1961 ◽  
Vol 39 (11) ◽  
pp. 1687-1693 ◽  
Author(s):  
T. K. Murray ◽  
J. A. Campbell
Keyword(s):  
Vitamin A ◽  
Antimony Trichloride ◽  
Vaginal Smear ◽  
Biological Potency ◽  
Liver Storage

The low biological potency of 9-cis and 9,13-di-cis vitamin A, heretofore measured by growth and liver storage assays, has been confirmed by vaginal smear assays. Appreciable quantities of these isomers in pharmaceuticals would lead to overestimation of biological potency by the U.S.P. XV or the antimony trichloride methods. In an extensive series of assays the U.S.P. method accurately estimated the biological potency of most oil-soluble, water-dispersed, and dry, stabilized samples of vitamin A. The antimony trichloride method did not accurately estimate biological potency but, for many samples, correction of these values in accordance with their maleic values was not justified. Water-dispersed and dry, stabilized samples of vitamin A were not better utilized than oil solutions of the vitamin.

scholarly journals A STUDY OF THE ANTIMONY TRICHLORIDE COLOR REACTION FOR VITAMIN A

1930 ◽  
Vol 85 (2) ◽  
pp. 477-489
Author(s):  
Earl R. Norris ◽  
Anna E. Church
Keyword(s):  
Vitamin A ◽  
Antimony Trichloride ◽  
Color Reaction
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