Room temperature and sensitive analysis of haloanisoles in wine using Vacuum-assisted headspace SPME with GC/ECD

Haloanisole contamination causes a musty/moldy off-aroma in affected wines, and results in significant economic loss for the wine and allied industries every year. The extremely low human sensory thresholds for these compounds require the use of highly sensitive analytical methods to detect them at odour threshold concentrations or lower. Using vacuum-assisted headspace solidphase microextraction (Vac-HS-SPME) sampling at room temperature followed by GC–ECD we developed a quick and sensitive procedure for the analysis of haloanisoles from wine. A comparative study between Vac–HS–SPME and regular HS–SPME was carried out and their greenness was evaluated using AGREEprep metric tool.

Introduction

Haloanisoles are well-known for creating a musty/moldy off-aroma in wines that is rejected by consumers, causing important economic losses for the wine industry. The defect is known as “cork taint” and is attributed to the cork stopper; though the problem can be widespread and affect the barrels, pipes and beams of a whole cellar. The main compounds responsible for the musty odor in wines are 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), pentachloroanisole (PCA) and 2,4,6-tribromoanisole (TBA), with TCA being detected in close to 80% of the positive samples. Because of the extremely low human sensory thresholds for these compounds (ppt level), highly sensitive analytical methods are needed to detect the haloanisoles at threshold concentrations or lower.

Headspace solid-phase microextraction (HS–SPME) followed by gas chromatography (GC) coupled - mass spectrometry or electron capture detection (ECD) is widely used for the detection and quantification of haloanisoles in wine. Reported methods require long extraction times or elevated SPME sampling temperatures to address the problem of low headspace concentrations. An alternative way to improve HS-SPME extraction efficiencies is to sample the headspace under reduced pressure conditions using the vacuum-assisted HS-SPME (Vac-HS-SPME) approach.