Determination of cyromazine in pesticide commercial formulations by vibrational spectrometric procedures

Two vibrational spectrometry-based methodologies were developed for Cyromazine determination in solid pesticide formulations: a Fourier transform infrared (FTIR) procedure, based on the extraction of Cyromazine by CH3OH and direct determination in the extracts by peak height measurement at 1622 cm(-1) corrected using a baseline defined at 1900 cm(-1), and a RT-Raman determination, made directly on the powdered solid products using standard chromatographic glass vials as sample cells and measuring the Raman intensity between 633 and 623 cm(-1) for a baseline established between 663 and 601 cm(-1). The sensitivity obtained was 0.01631 absorbance g-(1) mg for FTIR determination and 2.23 area values g(-1) g for FT-Raman. A repeatability of 0.2 and 0.4% as relative standard deviation (R.S.D.) and a limit of detection of 0.2 and 0.8% (w/w) were obtained for FTIR and FT-Raman determination, respectively. FTIR determination provides a sampling frequency of 60 h(-1), higher than the FT-Raman and LC ones, which were 25 and 6 h(-1), respectively. On the contrary FT-Raman reduces to the minimum the reagents consumption and waste generation, also avoiding sample handling and contact of the operator with the pesticide. Results obtained by both developed procedures were statistically comparable with those found by a reference liquid chromatography procedure. It can be concluded that the proposed methods are appropriate for quality control in pesticide commercial formulations. (C) 2004 Elsevier B.V. All rights reserved.