Abstract
| Language | English |
|---|---|
| Pages | 148-158 |
| Number of pages | 11 |
| Journal | Analytica Chimica Acta |
| Volume | 548 |
| Early online date | 11 Jul 2005 |
| DOIs | |
| Publication status | Published - 29 Aug 2005 |
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Keywords
- alcoholic beverages
- ethanol
- derivative spectrometry;
- NIR spectrometry
- raman spectrometry
- non-invasive analysis;
Cite this
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Comparison of non-invasive NIR and Raman spectrometries for determination of alcohol content of spirits. / Nordon, A.; Mills, A.; Burn, R.T.; Cusick, F.M.; Littlejohn, D.
In: Analytica Chimica Acta, Vol. 548, 29.08.2005, p. 148-158.Research output: Contribution to journal › Article
TY - JOUR
T1 - Comparison of non-invasive NIR and Raman spectrometries for determination of alcohol content of spirits
AU - Nordon, A.
AU - Mills, A.
AU - Burn, R.T.
AU - Cusick, F.M.
AU - Littlejohn, D.
PY - 2005/8/29
Y1 - 2005/8/29
N2 - The suitability of non-invasive NIR and Raman spectrometries for determination of % ethanol content has been investigated. Samples of whisky, vodka and sugary alcoholic drinks were analysed in 200 mL (flat) and 700 mL (round) glass bottles. The NIR spectrometer used double transmission measurements and was limited mainly to analysis of the signal produced at about 10,000 cm−1 by water and ethanol in the samples. The Raman measurements, produced using a 785 nm laser, were based on a sharp signal from ethanol at 880 cm−1. A multivariate calibration model, based on a combined PCA–PLS algorithm, was required for analysis by NIR spectrometry, whereas a univariate calibration model was suitable for Raman spectrometry. Both techniques were limited to measurements in clear glass bottles as strong absorption/fluorescence occurred with coloured glass bottles. Bottle-to-bottle variations contributed the largest uncertainty to the measurements obtained for a 20% (v/v) ethanol solution in flat bottles: 2.3% R.S.D. for NIR spectrometry and 2.2% R.S.D. for Raman spectrometry. For 700 mL round bottles, which have stricter manufacturing tolerances on glass thickness, the bottle-to-bottle variability for Raman spectrometry was 1.4% R.S.D. When spirit samples with ethanol concentrations in the range 19.9–61.7% (v/v) were analysed, the precision (average R.S.D.) was 0.4 and 0.5% for NIR (flat bottles) and Raman (round bottles) spectrometries, respectively, and the average accuracy was 2.1 and 2.9%, respectively. When a calibration model constructed from NIR data acquired on 1 day was applied to data sets collected over a 15-day period, the average error was 3.9%.
AB - The suitability of non-invasive NIR and Raman spectrometries for determination of % ethanol content has been investigated. Samples of whisky, vodka and sugary alcoholic drinks were analysed in 200 mL (flat) and 700 mL (round) glass bottles. The NIR spectrometer used double transmission measurements and was limited mainly to analysis of the signal produced at about 10,000 cm−1 by water and ethanol in the samples. The Raman measurements, produced using a 785 nm laser, were based on a sharp signal from ethanol at 880 cm−1. A multivariate calibration model, based on a combined PCA–PLS algorithm, was required for analysis by NIR spectrometry, whereas a univariate calibration model was suitable for Raman spectrometry. Both techniques were limited to measurements in clear glass bottles as strong absorption/fluorescence occurred with coloured glass bottles. Bottle-to-bottle variations contributed the largest uncertainty to the measurements obtained for a 20% (v/v) ethanol solution in flat bottles: 2.3% R.S.D. for NIR spectrometry and 2.2% R.S.D. for Raman spectrometry. For 700 mL round bottles, which have stricter manufacturing tolerances on glass thickness, the bottle-to-bottle variability for Raman spectrometry was 1.4% R.S.D. When spirit samples with ethanol concentrations in the range 19.9–61.7% (v/v) were analysed, the precision (average R.S.D.) was 0.4 and 0.5% for NIR (flat bottles) and Raman (round bottles) spectrometries, respectively, and the average accuracy was 2.1 and 2.9%, respectively. When a calibration model constructed from NIR data acquired on 1 day was applied to data sets collected over a 15-day period, the average error was 3.9%.
KW - alcoholic beverages
KW - ethanol
KW - derivative spectrometry;
KW - NIR spectrometry
KW - raman spectrometry
KW - non-invasive analysis;
U2 - 10.1016/j.aca.2005.05.067
DO - 10.1016/j.aca.2005.05.067
M3 - Article
VL - 548
SP - 148
EP - 158
JO - Analytica Chimica Acta
T2 - Analytica Chimica Acta
JF - Analytica Chimica Acta
SN - 0003-2670
ER -