FT–Raman spectrometry determination of Malathion in pesticide formulations

A fast and environmentally friendly method has been developed for Fourier transform–Raman (FT–Raman) spectrometry determination of Malathion in pesticide emulsifiable concentrate formulations. The method is based on the measurement of intensity peak height values at 1737 cm−1 Raman shift corrected using a baseline defined at 1900 cm−1. Samples were diluted with CHCl3 and the FT–Raman spectra collected in back-scattering mode over 3.3 min at a nominal resolution of 4 cm−1 accumulating 50 scans per spectra and using a laser power of 1250 mW. The developed procedure provided a limit of detection of 1.8% w/w in the original sample. Results found by FT–Raman spectrometry were statistically comparable with those obtained by flow injection Fourier transform infrared spectrometry, FIA–FTIR, and gas chromatography (GC) and were in good agreement with those reported by the manufacturer. The FT–Raman developed procedure reduces drastically the chlorinated solvent waste generation and avoids the contact of the operator with toxic products, being a fast alternative to the CIPAC recommended GC procedure.