0000000000016786
AUTHOR
M. Llobat Estellés
Apparent content curves: new analytical applications
Analytical possibilities of apparent content curves for ternary systems are studied. The mathematical method proposed is applied to UV-Vis spectrophotometric and fluorimetric techniques. Samples containing fluoresceine/eosine/acridine and methyl red/methyl orange/cresol red are resolved by fluorimetry and UV-spectroscopy, respectively. Results obtained are in agreement with the theoretical contents in both cases.
Use of the Apparent Content Curves for the spectrophotometric identification of substances: identification of amphetamines
The possibility of identification of substances which have similar spectral behaviour by means of Apparent Content Curves has been studied. This study is carried out with absorption, excitation and emission spectra of several amphetamines of widespread pharmaceutical use. Results obtained show that amphetamine, phenylpropanolamine, pseudoephedrine, phenylephrine, epinephrine, dopamine and methoxyamphetamine can be identified with a probability of >95%.
Apparent content curves: description and analytical applications. Resolution of binary mixtures
The apparent content curves and their analytical applications are described. Basing on these curves a mathematical method, which permits the identification of the interfering component present in a binary mixture as well as the determination of the contents of both constituents, is proposed. The existence of considerable interaction coefficients is not an impediment for its application. Besides, the analyte contents in the mixture can be obtained without the use of standard interference solutions. The proposed procedure is applied to the analysis of mixtures of dyes with overlapping absorption spectra.
Determination of Caffeine in Analgesic Formulations Using the Apparent Content Curves Method
Abstract The determination of caffeine by UV spectroscopy in pharmaceutical samples, containing different compounds which provide spectral interferences as aspirin, paracetamol, chlorfeniramine or propylphenazone, is carried out. The proposed procedure is based on the apparent content curves method in order to resolve binary, ternary and multicomponent mixtures. Results obtained are, in all cases, in agreement with contents found by a HPLC procedure used as reference method.