Search results for " infrared spectroscopy"
showing 10 items of 438 documents
Vibrational Spectrometry Strategies for Quality Control of Procymidone in Pesticide Formulations
2005
Abstract Two vibrational spectrometry–based methodologies were developed for procymidone determination in wettable powdered pesticide formulations. The Fourier‐transform infrared (FTIR) procedure was based on the selective extraction of procymidone by chloroform and determination by peak area measurement between 1451 and 1441 cm−1, using a baseline correction established between 1490 and 1410 cm−1, and a precision of 0.4% and a limit of detection of 0.01% w/w procymidone for a sample mass of 25 mg were obtained. For FT‐Raman determination, the selected conditions were peak area measurement between 1005 and 995 cm−1 Raman shift, with a baseline correction fixed between 1030 and 947 cm−1, and…
Quality control of Metamitron in agrochemicals using Fourier transform infrared spectroscopy in the middle and near range
2006
Abstract Two vibrational spectrometry-based methodologies were developed for Metamitron determination in pesticide formulations. Fourier transform-middle infrared (FT-MIR) procedure was based on the extraction of Metamitron by CHCl 3 and latter determination by peak area measurement between 1556 and 1533 cm −1 , corrected with a two points baseline established from 1572 to 1514 cm −1 . Fourier transform-near infrared (FT-NIR) determination was made after the extraction of Metamitron in acetonitrile and measuring the peak area between 6434 and 6394 cm −1 corrected using a two points baseline defined between 6555 and 6228 cm −1 . Repeatability, as relative standard deviation, of 5 independent…
Simultaneous determination of Folpet and Metalaxyl in pesticide formulations by flow injection Fourier transform infrared spectrometry
2003
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 gg −1 were found for Folpet and Metalaxyl, respectively, with results comparable with those found by liquid chromatography with…
Fourier transform infrared determination of Fluometuron in pesticide formulations
2003
Abstract A single method has been developed for Fourier transform infrared (FTIR) determination of Fluometuron in pesticide formulations. Samples were ultrasonically shaken with CHCl3 for 5 min and the FTIR spectra of sample extracts and standards were obtained at a nominal resolution of 4 cm−1 from 4000 to 900 cm−1 accumulating 25 scans. Fluometuron determination is based on the measure of peak area from 1342 to 1321 cm−1 corrected using a baseline defined from 1352 to 1294 cm−1. This procedure provided a limit of detection of 6.5 μg g−1, a sensitivity of 0.852 a.u. g mg−1 for a pathlength of 0.11 mm, a relative standard deviation of 1.6% for three analysis of a sample containing 50.4% (w/…
Determination of cyromazine in pesticide commercial formulations by vibrational spectrometric procedures
2004
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 FT-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 …
Novel approach for the determination of azithromycin in pharmaceutical formulations by Fourier transform infrared spectroscopy in film-through transm…
2013
Abstract This work reports the development of a new method for the determination of azithromycin in pharmaceutical formulations employing Fourier transform infrared (FTIR) technique. The measurements were performed using a novel approach based on a film-through transmission mode. Several variables that could influence the analytical performance of the method were evaluated (solvent, nominal resolution, number of scans, mode of measurement and spectral region selected for measurement). Acetonitrile was the best solvent for the determination of azithromycin, employing the absorption band of the C O group at 1729 cm− 1. The extraction of azithromycin from the formulations was made by mechanica…
Fourier transform infrared determination of imidacloprid in pesticide formulations
2004
A simple method has been developed for Fourier Transform Infrared (FTIR) determination of Imidacloprid in pesticide formulations. Samples were diluted with CHCl3 and the FTIR spectra of samples and standards were obtained at a nominal resolution of 4 cm-1 from 4000 to 900 cm-1 accumulating 25 scans. Imidacloprid determination was based on the measure of either peak area from 1577 to 1567 cm-1 or peak height at 1572 cm-1, both corrected using a horizontal baseline defined at 1900 cm-1. The limits of detection achieved, of the order of 9 µg g-1, were appropriate for the determination of Imidacloprid in commercially available formulations. FTIR results were statistically comparable to those fo…
Development of a simple and low cost device for vapour phase Fourier Transform Infrared spectrometry determination of ethanol in mouthwashes
2006
Abstract A new vapour phase manifold coupled with Fourier Transform Infrared (FTIR) spectroscopy was developed for ethanol determination in mouthwashes. Two microliters of samples were injected, without any previous pre-treatment into a reactor heated at 70 °C, and the vapour phase generated transported to the FTIR spectrometer using a carrier nitrogen flow of 6 ml min−1. FTIR spectra were continuously recorded, as a function of time, by accumulating two scans and employing 8 cm−1 nominal resolution. Analytical measurements for ethanol were made in the range from 1130 to 992 cm−1 with a baseline defined between 1158 and 957 cm−1. After ethanol measurement the carrier flow was increased to 3…
An Infrared Method, with Reduced Solvent Consumption, for the Determination of Chlorsulfuron in Pesticide Formulations
2003
A simple method has been developed for the determination of Chlorsulfuron in pesticide formulations by Fourier Transform Infrared (FTIR). Samples were diluted with CHCl3− , and the FTIR spectra of the samples and standards were obtained at a nominal resolution of 4 cm− 1 from 4000 to 900 cm− 1 with the accumulation of 25 scans. Chlorsulfuron determination was based on the measurement of peak area values from 1373 to 1363 cm− 1 which were corrected by use of a two points baseline defined from 1401 to 1302 cm− 1. The limit of detection achieved, which was of the order of 6 µg g− 1, was appropriate for the determination of Chlorsulfuron in commercially available formulations. FTIR results were…
Determination of caffeine in tea samples by Fourier transform infrared spectrometry
2002
A sustainable and environmentally friendly procedure has been developed for the FTIR determination of caffeine in tea leaf samples. The method is based on the extraction with ammonia and CHCl3 and direct determination of caffeine on the chloroform extracts using peak height absorbance measurements at 1658.5 cm(-1) and external calibration. The method provides a sensitivity of 0.2142 absorbance units mg(-1) mL and a limit of detection of 1 mg L(-1), corresponding to 0.002% m/m caffeine in tea leaves. As compared with a reference procedure, based on UV absorbance measurement at 276 nm after low pressure column chromatography, the developed procedure reduces the consume of CHCl3 by a factor of…