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The chemical evaluation of pyrethrum flowers (Chrysanthemum cinerariaefolium): A comparison of several methods

Published online by Cambridge University Press:  27 March 2009

J. T. Martin
J. T. Martin
Affiliation:
Department of Insecticides and Fungicides, Rothamsted Experimental Station, Harpenden, Herts
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Extract

1. Comparative analyses of pyrethrum flowers have been carried out by the methods of Tattersfield, Seil, Ripert, Haller & Acree and Wilcoxon.

2. The methods were of value in indicating the relative richness in pyrethrins of the samples tested, but discrepancies were seen in the absolute values of the pyrethrins I and II recorded. Under present conditions and until a standard method of analysis is agreed upon, it would appear requisite to state the method employed in the evaluation of the flowers.

3. The Wilcoxon method has given higher figures for the pyrethrin I content than the Seil method. The degree of divergence between the results depended upon the richness of the flowers, and upon the excess of acid used in distilling the volatile acid in the Seil method. The relationship between the amount of the pyrethrin I acid present and the titration recorded in the Wilcoxon method was not a linear one.

4. The question of the solvent to be used for the initial extraction of the flowers has been briefly discussed.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 28 , Issue 3 , July 1938 , pp. 456 - 471
Copyright
Copyright © Cambridge University Press 1938

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References

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