Abstract

Chloroanisoles can migrate from the cork stopper in wine bottles to the wine and give it a musty taint so it is important to find a method by which they can be determined. The aim of this paper is to develop a method for quantifying 2,4-dichloroanisole, 2,6-dichloroanisole, 2,4,6-trichloroanisole, 2,3,4,6-tetrachloroanisole and 2,3,4,5,6-pentachloroanisole in cork using headspace solid-phase microextraction and gas chromatography with electron capture detection. After we had prepared the cork standards that were so essential to the work we optimised the parameters that most influence headspace solid-phase microextraction: fibre coating, vial volume, cork, kind and volume of solvent to help the extraction, extraction temperature and time, ionic strength and stirring. The method quantifies the total amount of chloroanisoles in cork stoppers (natural, agglomerated, agglomerated with disks and sparkling wine stoppers), at suitable concentrations so that the capacity of these compounds to give wine a musty taint can be evaluated. The quantification limits are: 2,6-dichloroanisole (8.6 ng/g), 2,4,6-trichloroanisole (0.8 ng/g), 2,4-dichloroanisole (3.5 ng/g), 2,3,4,6-tetrachloroanisole (0.6 ng/g), 2,3,4,5,6-pentachloroanisole (0.8 ng/g). The other quality parameters are: recoveries (90.3–105.8%), repeatability (4–13% (RSD expressed)) and intermediate precision (5–14% (RSD expressed)).

Keywords: Cork; Chloroanisoles; 2,4-Dichloroanisole; 2,6-Dichloroanisole; 2,4,6-Trichloroanisole; 2,3,4,6-Tetrachloroanisole; 2,3,4,5,6-Pentachloroanisole; Solid-phase microextraction; Headspace analysis; Gas chromatography and electron capture detection; Cork taint

Article Outline

1. Introduction

2. Methods and materials

2.1. Chemicals and reagents

2.2. Cork sample preparation

2.3. SPME fibres

2.4. HS-SPME procedure

2.5. Statistical analysis

2.6. Instrumental analysis

3. Results and discussion

3.1. HS-SPME parameters optimisation

3.2. Preparation of cork standards

3.2.1. Cork blanks

3.2.2. Ground or unground cork

3.2.3. Addition of chloroanisoles

3.3. Analytical performance parameters

3.3.1. Calibration curves

3.3.2. Recoveries

3.3.3. Repeatability and intermediate precision

4. Conclusions

Acknowledgements

References