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ID 116472
Author
Kurokawa, Yohei Tokushima University
Keywords
Flow analysis
Flow rate modulation
Fast Fourier transform
Speciation
Ferrous and ferric ions
Amplitude modulation
Content Type
Journal Article
Description
We propose a novel concept of flow-based analysis for spectrophotometric speciation based on flow rate modulation and fast Fourier transform (FFT). A redox reagent solution's and a sample solution's flow rates are varied by sinusoidal control signals with periods of T and 0.5T, respectively. Both solutions are merged with a color reagent, while the total flow rate is held constant. Downstream, the absorbance of the mixed solution is measured and acquired as the detector output voltage (Vd). The Vd is analyzed by FFT with the window's time length of T. One species that directly reacts with the color reagent contributes only to the amplitude (A2) of the second harmonic wave component in Vd. The other species that needs the redox conversion before the coloration contributes to the amplitude (A1) of the fundamental wave component, in addition to A2. The former species+' concentration can be estimated from A2 by taking the latter's contribution to A2 into account. The latter species’ concentration can be determined only from A1. The proposed concept was demonstrated by applying it to the speciation of Fe2+ and Fe3+ by an o-phenanthroline spectrophotometry, where Fe3+ was reduced to Fe2+ by L-ascorbic acid before the coloration.
Journal Title
Talanta Open
ISSN
26668319
Publisher
Elsevier
Volume
3
Start Page
100031
Published Date
2021-01-19
Rights
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
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DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher
departments
Pharmaceutical Sciences
Science and Technology