0000000000542237
AUTHOR
Z.a. De Benzo
Some observations on the determination of the methyl parathion-parathion ratio in binary mixtures by infrared spectroscopy
Abstract The determination of the methyl parathion/parathion ratio in binary mixtures has been carried out by infrared spectroscopy using a simple and easy model for the treatment of the spectra obtained from sample thin films using sodium chloride windows. The model is based on the use of two bands, one at 974 cm−1, characteristic of parathion, and other at 1348 cm−1, common to both compounds. From the spectra of pure parathion samples and mixtures of known composition of methyl parathion and parathion, two constants have been obtained. These constants relate the absorption of each compound at 1348 cm−1 to the absorption of parathion at 974 cm−1. Eighteen synthetic samples have been analyz…
Rapid hydrolysis of benzodiazepines to benzophenones in a microwave oven
Abstract A microwave oven is used to carry out the complete hydrolysis of diazepam to the corresponding benzophenone in only 10 min, at 650 W, with good recovery. The reaction yield is evaluated by first-derivative UV spectrophotometry.
Direct derivative spectrophotometric determination of carbaryl and carbofuran in water samples
Abstract Derivative absorption spectrophotometry has been applied to the direct determination of carbaryl and carbofuran in water samples. The use of the third derivative for carbaryl and the fourth derivative for carbofuran reduces the matrix effect and the seventh derivative provides, in both cases, accurate results for the determination of these pesticides, even working at low dilution levels of the samples. A limit of detection of 4 ppb and a variation coefficient of 0.1% have been obtained for the determination of carbaryl. Carbofuran can be determined with a limit of detection of 5 ppb and a variation coefficient of 0.02%.