Application of sulphanilamides disazo dyes with Tropaeolin O for simple, rapid and sensitive spectrophotometric assay of medicines

Development and validation of the simple and sensitive spectrophotometric method of sulphanilamides determination with 4-(2-thiazolylazo)-resorcinol in veterinary preparations

“…All these effects are related to the distribution of electron density in the molecules of both the SA and TAR, as well as in the products of their interaction, and also to the availability of mesomeric and inductive effects of substituents [44,45]. The results of investigation correlate with the results obtained in the study of the interaction of SA diazonium salts with another heterocyclic azo reagent 4-(2-pyridylazo) resorcinol [39,40] and acid monoazo dye Tropaeolin O [37,38].…”

“…In particular using of alizarin and its derivatives is known [36]. At our laboratory we have previously developed the techniques of SA determination using the mono azo dye Tropaeolin O [37,38] and heterocyclic azo reagent 4-(2-pyridylazo) resorcinol [39,40] as well as o,o'-dihydroxysubstituted azo dyes eriochrom blue SE [41], eriochrom blue-black R [42] and eriochrom black T [43]. The aim of this research is to establish the conditions of SA interaction with another heterocyclic azo reagent 4-(2-thiazolilazo)-resorcinol for obtaining of maximum analytical signal and the development of method of SA quantitative determination with satisfactory validation characteristics.…”

Development and Validation of the Simple and Sensitive Spectrophotometric Method of Amoxicillin Determination in Tablets using Sulphanilamides

“…30 Besides, due to the presence of the primary aromatic amino group, the sulphanilamides enter into a diazotization reaction with the next azo-coupling with various phenolic compounds. In particular, we have previously studied the conditions for sulphanilamides diazotization and their subsequent azo copling with hydroxy-substituted azo compounds, namely, with the acid monoazo dye Tropaeolin O (TrO) 30,31 and heterocyclic azo reagents 4-(2-pyridylazo)-resorcinol 30,32 (PAR) and 4-(2-thiazolylazo)-resorcinol (TAR). 30,33 The absorbance maxima of the obtained nitroso disazo compounds at the spectrum range 590-620 nm [30][31][32][33] have been successfully used for the sulphanilamides determination in dosage forms.…”

Eriochrome Black T – a New Analytical Reagent for Spectrophotometric Determination of Sulphanilamides

“…However these reactions are characterized by a low contrast. Previously we developed techniques of spectrophotometric SA determination with application of azo reagents, such as acid mono azo dye tropaeolin O [15,16], heterocyclic azo reagents 4-(2-pyridylazo) resorcinol [17,18], and 4-(2-thiazolylazo) resorcinol [19], which are characterized by a high sensitivity and selectivity at the presence of other classes of biologically active substances. The goal of our investigation was the search of effective analytical reagents for SA determination by the examining of azo dyes; one of them is o,o'-dihydroxysubstituted azo dye eriochrom black T (EBT).…”