Determination of piperonyl butoxide by gas chromatography

Abstract

A gas chromatographic method has been developed for the determination of piperonyl butoxide in technical piperonyl butoxide. The sample is dissolved in a solvent containing a definite concentration of dioctyl phthalate as an internal standard, and the piperonyl butoxide is determined by relating the area of the piperonyl butoxide peak to that of dioctyl phthalate. The method is precise and results are slightly lower than those of the AOAC colorimetric method. The procedure is also applicable to common blends of pyrethrins and piperonyl butoxide.Gas chromatographic studies of insecticidal concentrates containing piperonyl butoxide (the butyl carbitol ether of 3,4-methylenedioxy-6-propylbenzyl alcohol) indicated the feasibility of a gas chromatographic method for the determination of this widely used synergist for pyrethrins and related ins.cticides.The AOAC method (1965) is the most common procedure used for determining piperonyl butoxide in the technical grade material, insecticidal concentrates, or finished formulations. Other methods applicable to pyrethrum synergists which contain the methylenedioxyphenyl group have been reported by Beroza (1956) andBlum (1955). The AOAC method was developed by Jones et al. (1952) and is based on the blue color produced by heating piperonyl butoxide with tannic acid in the presence of phosphoric and acetic acids. Interferences which have been reported are pyrethrins, allethrin, alkylated naphthalenes, cyclohexanone, and high-boiling hydrocarbons (Allen et a/., 1962; Jones et al., 1952). Jones et al. (1952),