Colourimetric solid‐phase extraction coupled with fibre optic reflectance spectroscopy for determination of ascorbic acid in pharmaceutical formulations

Abstract

A redox colourimetric solid-phase extraction (C-SPE) procedure for the determination of ascorbic acid (AA) in pharmaceutical formulations was proposed. Iron (III)-2,2'-dipyridyl (Fe(III)-Bpy) reagent solution was used as a colouring reagent for AA and the immobilization of the redox product onto Amberlite XAD-16 resin was achieved. The analyte in the sample reacted with a solid sorbent loaded with the colourimetric reagent (Fe(III)-Bpy) and then quantified directly on the sorbent surface by using a fibre optic reflectance spectrometer (FORS). The amount of AA was reflectometrically determined in a few seconds with a total sample workup and readout time of ∼10 min using only 10-ml sample volumes. The limit of detection (LOD) and quantification (LOQ) values were 0.18 and 0.6 mg L(-1), respectively, and the linear dynamic range for AA extended up to 8.8 mg L(-1). The C-SPE for different extractions (n = 5) gave a relative standard deviation (RSD) of 2.9% at 5.28 mg L(-1) AA level.

Flow-Injection Chemiluminescence Method for Sensitive Determination of Ascorbic Acid in Fruit Juices and Pharmaceutical Samples Using a Luminol-Cetyltrimethylammonium Chloride Reversed Micelle System

“…6 There have been several techniques reported so far for the quantitative determination of AA such as spectrophotometric, 7,8 fluorometric 9,10 and electrochemical 11,12 methods, high-performance liquid chromatography, 13 and solid phase analysis. 14,15 However, there are several disadvantages associated with these methods, e.g., the requirement of sophisticated infrastructure and expertise, time-consuming procedure, high operating cost, background interference in fluorometric detection, etc. For the determination of AA, a selective, automated, rapid, inexpensive and simple method is thus needed in routine analyses.…”

Nano/Mesoporous Carbon from Rice Starch for Voltammetric Detection of Ascorbic Acid

“…Different methods have been developed for determination of AA in different matrices, including by titration, UV–vis spectrophotometry, capillary electrophoresis, fiber-optic reflectance spectroscopy, HPLC, thermogravimetry, fluorometry, etc. [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Electrochemical techniques offer advantages of simplicity, selectivity, stability, and applicability in different matrices.…”

Sensitive determination of trace mercury by UV–visible diffuse reflectance spectroscopy after complexation and membrane filtration-enrichment

“…In recent years, colorimetric solid phase extraction (C-SPE) has been utilized, which is based on the extraction of analytes onto a proper support loaded with a colorimetric reagent and then quantified directly on the solid support surface using reflectance spectroscopy [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. The main advantage of C-SPE is that the elution step of SPE can be completely eliminated.…”