Simultaneous determination of Folpet and Metalaxyl in pesticide formulations by flow injection Fourier transform infrared spectrometry Original Research Article

Fourier transform infrared (FTIR) spectrometric methodology has been developed for the simultaneous determination of Folpet and Metalaxyl in pesticide formulations. The method involves the extraction of both active principles by sonication of the sample with CHCl3 and direct measurement of the absorbance using peak height values at 1798 cm−1 corrected with a baseline defined at 1810 cm−1 for Folpet, and peak area data established from 1677 to 1667 cm−1 corrected using a baseline from 1692 to 1628 cm−1 for Metalaxyl. Limits of detection (3 s) values of 17 and 16 μg g−1 were found for Folpet and Metalaxyl, respectively, with results comparable with those found by liquid chromatography with UV detection. The new method involves a considerable decrease in solvent consumption. The automation of the procedure by incorporating on-line dissolution and filtration of the samples allows complete mechanisation of the method and improves the safety of operation.