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Rapid method for the determination of ‘total pyrethrins’ by spectroscopy of their 2,4‐dinitrophenylhydrazones
Author(s) -
Head S. W.
Publication year - 1964
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740150608
Subject(s) - pyrethrum , chemistry , chromatography , molar absorptivity , optical density , pesticide , physics , optics , agronomy , biology , medicine , ophthalmology
A rapid method for the analysis of pyrethrum extract and pyrethrum formulations containing synergists and emulsifying agents has been developed. The pyrethrins are converted into their 2,4‐dinitrophenylhydrazones and, without chromatography , the optical density at 377 m p determined. The optical density is converted into pyrethrin concentration by using the value ϵ = 28,000 for the molecular extinction coefficient of the pyrethrin dinitrophenylhydrazones.