Encontrados 9 documentos, a visualizar página 1 de 1
Pilot monitoring study of ibuprofen in surface waters of north of Portugal
Paíga, Paula; Santos, Lúcia; Amorim, Célia G.; Araújo, Alberto N.; Montenegro, M. Conceição B. S. M.; Pena, Angelina; Delerue-Matos, CristinaIbuprofen is amongst the most worldwide consumed pharmaceuticals. The present work presents the first data in the occurrence of ibuprofen in Portuguese surface waters, focusing in the north area of the country, which is one of the most densely populated areas of Portugal. Analysis of ibuprofen is based on pre-concentration of the analyte with solid phase extraction and subsequent determination with liquid chrom...
Development of a simple analytical method for the simultaneous determination of...
Santos, Lúcia H. M. L. M.; Paíga, Paula; Araújo, Alberto N.; Pena, Angelina; Delerue-Matos, Cristina; Montenegro, M. Conceição B. S. M.Paracetamol is among the most worldwide consumed pharmaceuticals. Although its occurrence in the environment is well documented, data about the presence of its metabolites and transformation products is very scarce. The present work describes the development of an analytical method for the simultaneous determination of paracetamol, its principal metabolite (paracetamol-glucuronide) and its main transformation p...
A multicommuted flow analysis method for the photometric determination of amoxi...
Freitas,Sueny K. B; Silva,Valdinete Lins da; Araújo,Alberto N; Montenegro,Maria Conceição B. S. M; Reis,Boaventura F; Paim,Ana Paula SA multicommuted flow analysis method for the spectrophotometric determination of amoxicillin in pharmaceutical formulations is reported. The proposed method is based on the reaction of diazotised o-nitroaniline with amoxicillin in an alkaline medium, producing a yellow compound that was monitored at 435 nm. The main features of the method were: a linear relationship with amoxicillin concentration ranging from 2...
Gran method for end point anticipation in monosegmented flow titration
Aquino,Emerson V; Pasquini,Celio; Rohwedder,Jarbas J. R; Raimundo Jr,Ivo M; Montenegro,M. Conceição B. S. M; Araújo,Alberto NAn automatic potentiometric monosegmented flow titration procedure based on Gran linearisation approach has been developed. The controlling program can estimate the end point of the titration after the addition of three or four aliquots of titrant. Alternatively, the end point can be determined by the second derivative procedure. In this case, additional volumes of titrant are added until the vicinity of the en...
Determination of gibberellic acid by sequential injection analysis using a pote...
Santos,Emília M. G.; Couto,Cristina M. C. M.; Araújo,Alberto N.; Montenegro,M. Conceição B. S. M.; Reis,Boaventura F.This work describes the determination of gibberellic acid in growth promoters formulations used in agriculture by sequential injection analysis and potentiometric detection. The potentiometric detectors with improved characteristics used a PVC membrane prepared with Mn(III)tetraphenylporphyrin-Cl as electroactive specie. Different membranes formulated with several ionic additives were compared in order to selec...
Determinação potenciométrica em fluxo de cloreto de cetilpiridinio em desinfect...
Baptista,Paula C. S.; Araújo,Alberto N.; Montenegro,Maria da Conceição B. S. M.The work describes a new procedure for cetylpyridinium chloride determination in oral disinfectants, based on a flow-injection system with potentiometric detection. The determination was based on the measurement of picrate concentration decrease as result of ion-pair reaction with the analyte present in the injected sample. In the optimised set-up the sample injection volume was kept at 400 µL and merged downst...
Monosegemented flow potentiometric titration for the determination of chloride ...
Vieira,Jonas A.; Raimundo Jr.,Ivo M.; Reis,Boaventura F.; Montenegro,M. Conceição B.S.M.; Araújo,Alberto N.An automated flow potentiometric titration procedure for the determination of chloride in milk and wine exploiting the monosegmented flow approach is described. The flow network was designed based on a six-way solenoid valve, controlled by a microcomputer running software written in VisualBasic 3.0, allowing selection of the titration conditions. An Ag2S tubular electrode selective for Cl- and a conventional Ag...
Potentiometric determination of cetylpyridinium chloride in oral desinfectants ...
Baptista, Paula; Araújo, Alberto N.; Montenegro, Maria da Conceição B. S. M.The work describes a new procedure for cetylpyridinium chloride determination in oral disinfectants, based on a flow-injection system with potentiometric detection. The determination was based on the measurement of picrate concentration decrease as result of ion-pair reaction with the analyte present in the injected sample. In the optimised set-up the sample injection volume was kept at 400 µL and merged downst...
Sequential injection system for the spectrophotometric determination of reducin...
Araújo, Alberto N.; Lima, José L. F. C.; Rangel, António O. S. S.A sequential injection system for the spectrophotometric determination of reducing sugars in wines is described. The methodology is based on the formation of a coloured complex produced by the reaction of copper (I) with 2,9-dimethyl-1,10-phenanthroline (neocuproine), after reduction of copper (II) to copper (I) by reducing sugars. In the present SI system, a dialysis unit was incorporated not only to allow the...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||