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

Filik H. , Aksu D., Giray D., Apak R.

DRUG TESTING AND ANALYSIS, cilt.4, ss.493-499, 2012 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 4 Konu: 6
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1002/dta.267
  • Sayfa Sayıları: ss.493-499


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 similar to 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. Copyright (c) 2011 John Wiley & Sons, Ltd.