Estimation of Micro Quantities of Pyrethroids

Abstract

Ix recent attempts to estimate small quantities of pyrethrins in flour which had been stored in pyrethrum-treated cotton bags ( 14), the extraction from cotton, paper, and other media was found to be difficult and there were apparent limitations in the accuracy of the analysis of pyrethroids-i.e., chrysanthemum esters of alkyl cyclopentenolones by the Association of Official Agricultural Chemists (AOAC) 1950 Method (1). Since then, these problems have been given further consideration in this

Infrared Spectophotometric Determination of Allethrin

“…A short while later (10) Harper and Sleep observed that chrysanthemumonitrile contains 73 % of this isomer. By means of a modified AOAC method (1), the quantity of ¿'/•cms-chrysanthemummonocarboxylic acid present in the racemic acid was found to be nearly identical with that reported in this paper (19).…”

Gas Chromatographic Analysis of Pyrethrin-Type Esters and Dimethrin Isomers.

“…In the colorimetric procedure of Schreiber and McClellan (7) suitable for pyrethroid compounds such as allethrin, dimethrin, and pyrethrins, the Denigés reagent is reduced by chrysanthemumic acid, yielding various shades of color such as the salmon red, turning to a raspberry red, in contrast to the pink to stable purple obtained for allethrin and chrysanthemumic acid (racemic mixture of the dl-cis and dltrans acids), respectively.…”