Compendium of International Methods of Analysis for Spirituous Beverages and alcohols

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OIV-MA-BS-21 UV absorption of rectified alcohols of vitivinicultural origin

Method OIV-MA-BS-21 : R2009

Type IV method

UV absorption of rectified alcohols of vitiviniculture origin

(OENO 6/94;

OIV/OENO 382A/2009)

1.                Purpose and scope

This method can be used to determine the optical permeability of neutral alcohol liable to enter into the composition of certain alcoholic beverages.

2.                Principle

The optical permeability of the sample in the wavelength range from 220 to 270 nm is measured against a defined reference substance with high optical permeability.

3.                Apparatus

3.1.      UV-visible spectrophotometer.

3.2.      Quartz cells 10 mm thick, with identical spectral transmission.

4.                Reagents

Hexane for spectroscopy.

5.                Procedure

  • Rinse the tanks clean beforehand with a sample solution and then fill with the sample, dry the tanks outside,
  • treat the reference cell (n) with hexane in the same way and fill it,
  • determine the absorbance value and build the graph.

6.                Expression of results

The absorbance values recorded at 270, 240, 230 and 220 nm should not exceed the following values: 0.02, 0.08, 0.18 and 0.3. The absorbance curve must be smooth and regular.

7.                Bibliography

  1. Methods of analysis of neutral alcohol applicable in the wine sector. EEC Regulation No. 1238/92 (May 8, 1992), EEC Regulation No. 2009/92 (July 20, 1992).