Infrared spectrophotometric determination of Phthalthrin isomers: Analytical studies on pesticides by infrared spectroscopy. V

An infrared spectrophotometric method has been developed for the determination of Phthalthrin isomers. The amounts of trans-isomer and cis-isomer were determined by their absorbances at 1148 cm-1 and 1070 cm-1 respectively, with the base line technique in carbon disulfide solution. On the other hand, the total Phthalthrin content could be determined by use of the isoabsorption point of two isomers at 1132 cm-1. The impurities do not interfere at these analytical wave numbers. And the results of both the infrared spectrophotometric method and thin layer chromatographic separation-ultraviolet spectrophotometric method were in excellent agreement on technical Phthalthrin samples.