6533b859fe1ef96bd12b834c

RESEARCH PRODUCT

Flow-Injection Spectrophotometric Determination of Phenolic Drugs and Carbamate Pesticides by Coupling with Diazotized 2,4,6-Trimethylaniline

Escrig-tena IGarcia Alvarez-coque McAlvarez-rodriguez LJosep Esteve-romero

subject

InsecticidesCarbamateEpinephrineMethiocarbmedicine.medical_treatmentAnalytical Chemistrychemistry.chemical_compoundPhenolsmedicineEnvironmental ChemistryPhenolsSodium dodecyl sulfateAcetaminophenPharmacologyFlow injection analysisAniline CompoundsChromatographyAqueous solutionHerbicidesGuaiacolWaterDiazonium CompoundsHydrogen-Ion ConcentrationPharmaceutical PreparationschemistrySpectrophotometryReagentFlow Injection AnalysisPromecarbIndicators and ReagentsCarbamatesAgronomy and Crop ScienceFood Science

description

Abstract A flow-injection (FI) spectrophotometric system is proposed for the determination of phenols and carbamates. In the FI manifolds, the solutions of phenols or carbamates (the latter after hydrolysis with NaOH) were injected into a diazonium ion carrier stream at pH 9.5 (buffered with tetrahydroborate), which was formed by mixing 2,4,6-trimethylaniline (TMA) with nitrate in a sodium dodecyl sulfate aqueous micellar medium. Absorbance was measured at 550 nm. The system combines the advantages derived from the use of TMA for the coupling of phenols in basic micellar media, because of the inhibition of the self-coupling reaction of the reagent, with the precision and speed of the FI procedures. Other diazotized reagents produced excessive blank signals. The procedures were successfully applied to the determination of phenolic drugs (epinephrine, acetaminophen, and guaiacol) in pharmaceuticals and carbamates (bendiocarb, benfuracarb, carbaryl, carbofuran, methiocarb, promecarb, and propoxur) in pesticide products and water samples.

https://doi.org/10.1093/jaoac/82.4.937