Sensitive determination of terazosin by x‐ray fluorescence spectrometry based on the formation of ion‐pair associates with zinc thiocyanate

Abstract

A new, simple and precise indirect method for the determination of terazosin through x‐ray fluorescence (XRF) is proposed. The method is based on the precipitation of an ion‐associate complex formed between terazosin and [Zn(SCN)4]2− and the formation of a thin film on a membrane filter. The optimum conditions for ion‐associate complex formation, such as pH, ionic strength, shaking time and stoichiometry of the complex, were studied. The complex was retained on the membrane filter, and the Zn Kα line was measured by XRF. The method presents the advantages of the separation of the drug from the matrix (excipients), the preconcentration of Zn, producing enhancement of XRF intensity though increased sensitivity, and the elimination of the matrix effects due to the thin film obtained. The lowest detection limit was 0.732 µg ml−1. The validation studies were realized by the related applications and the results were evaluated statistically. The method was successfully applied to terazosin determination in tablets or in bulk. Copyright © 2007 John Wiley & Sons, Ltd.

A Specific High-Performance Thin-Layer Chromatography with Fluorescence Detection for the Determination of Some α1-Blockers

“…[6,7] Recently, several analytical methods have been used for the determination of a 1 -blockers in bulk form, pharmaceutical formulations, and biological fluids. [8] These include spectrophotometry, [9][10][11] spectrofluorimetry, [12][13][14][15][16] thin-layer chromatography (TLC), [17,18] high-performance thinlayer chromatography (HPTLC), [19,20] high-performance liquid chromatography (HPLC) with UV, [21][22][23][24][25][26] fluorescence, [27][28][29][30] and mass detection. [31] Although two HPTLC methods were reported for the determination of a 1 -adrenergic blockers, this was the first HPTLC method to use fluorescence detection mode for the determination of a 1 -blockers.…”

Graphene oxide-based solid phase extraction of vitamin B12from pharmaceutical formulations and its determination by X-ray fluorescence

“…So far, only a few paper presented an indirect method for the determination XRF determination of organic compound. The method is based on the precipitation of an ion‐associate complex formed between terazosin (as target analyte) and [Zn(SCN) 4 ] 2− and the formation of a thin film on a membrane filter . To the best of our knowledge, this is the first report about the application of the XRF for the determination of vitamin B 12 which have one cobalt atom in its structure.…”