FTIR Approaches for Diuron Determination in Commercial Pesticide Formulations

Abstract

Two strategies have been developed for Diuron determination by FTIR spectrometry, an off-line extraction and stopped-flow determination and a fully mechanized procedure, based on the on-line extraction of Diuron and FIA-FTIR measurement of the extracts. The aforementioned procedures have been compared with a reference chromatographic method. The off-line FTIR spectra were obtained at a nominal resolution of 4 cm(-1) from 4000 to 900 cm(-1) by accumulating 25 scans. Diuron was determined using peak height measurements at 1582 cm(-1) corrected using a baseline defined between 1562 and 1614 cm(-1). The waste generation of the off-line procedure was 3.4 mL chloroform for each sample, and the method provided a LOD of 40 microg g(-1), corresponding to 0.8% (w/w) Diuron in the original sample. The fully mechanized FIA method provided a LOD of 35 microg g(-1), which corresponds to 0.7% (w/w) in the solid sample and a maximum sampling frequency of the whole procedure of 30 h(-1), with a waste generation of 9.3 mL per sample, taking into account the volume of CHCl(3) required for sample dissolution and that need as a carrier. All those methods consume less organic solvent than a HPLC method, which involves the use of 39 mL of acetonitrile per sample and a sampling frequency of 12 h(-1).

Hydrothermal Carbonization of Argan Nut Shell: Functional Mesoporous Carbon with Excellent Performance in the Adsorption of Bisphenol A and Diuron

“…The strong and broadband between 4000 and 3000 cm − 1 could be assigned to N-H and O-H stretching vibration, which is overlapping after adsorption of diuron on HTC@ANS-200. For diuron, a carbonyl band at 1636 cm −1 and a benzene ring stretching band at 1521, 1469, and 1354 cm −1 were recognized [77,78]. Other bands located at 1580 cm −1 were assigned to C=C stretching vibration, while the band at 1182 cm −1 was due to the C-H in-plane bending vibration of the benzene ring.…”

Calibration of Raman Spectroscopy at 1064 nm for Beeswax Quantification

“…To obtain an absolute Raman intensity in the quantitative analysis of our hydrocarbon mixtures, we have used an external standard, as recommended by some authors. 24 The nylon plate (6 3 15 3 12 mm) from the accessory kit of the spectrometer (Bruker) was selected as the external reference to correct the Raman emission dependence on the laser beam power 25 because it presents an absorption band centered in the same frequency range where the beeswax has its characteristic identifying peak. Immediately after every measurement of a set of beeswax samples at a particular laser power, the nylon spectrum was recorded.…”

Determination of active ingredients in commercial insecticides using spectral characteristics of Fourier transform infrared spectroscopy (FTIR)

“…Cyromazine determined with FT-IR and FT-Raman procedure were found statistically compared with reference liquid chromatography procedure and showed the FTIR methods were appropriate for quality control in commercial pesticide formulations (Armenta et al, 2004). The waste generation in FT-IR for diuron determination was 3.4 ml CHCl 3 , in flow injection analysis 9.3ml CHCl 3 per sample and those methods consume less organic solvent than an HPLC method, which involves the use of 39 mL of acetonitrile per sample (Armenta et al, 2005b). By utilizing FTIR spectrometry, the immediate assurance of malathion in commercial pesticide formulations can be completed, with no pre-treatment of tests, with reproducibility and precision practically identical to those measured utilizing GC -FID, besides, decreasedtime and volume of chlorinated solvents utilized (from 35 ml of CHCl 3 to 2 ml) in the analysis (Quintás et al, 2004b).…”