Improving accuracy and reproducibility of vibrational spectra for diluted solutions

Dušan Kojić, Roumiana Tsenkova, Masato Yasui

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

In what appears to be a trivial operation in which the averaged spectrum of solvent is subtracted from the spectra of solutions, can be a misleading step in improving reproducibility of vibrational spectra. Near-infrared spectra of pure water and glycine solutions were used to quantify instrumental and spectral variations, and examine its influence on the reproducibility of difference spectra over a wide concentration range. Significant improvements were observed (fourfold), in comparison with the most commonly applied technique that uses an averaged spectrum of solvent. We propose a new technique, in which subtraction of the closest spectrum of solvent involves calculating the smallest area under the subtracted curve, to extract the optimal outcome. These results reveal that, contrary to common practice, reproducibility for spectra of diluted solutions can bypass even instrumental baseline shifts and render results that are limited only by the noise originating from the instrument's sensor.

Original languageEnglish
Pages (from-to)86-97
Number of pages12
JournalAnalytica Chimica Acta
Volume955
DOIs
Publication statusPublished - 2017 Feb 22

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Keywords

  • Hydrogen bonding
  • Near infrared spectroscopy
  • Spectral pre-processing
  • Spectral subtraction
  • Water

ASJC Scopus subject areas

  • Analytical Chemistry
  • Environmental Chemistry
  • Biochemistry
  • Spectroscopy

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