A simple, rapid and effective method was successfully developed for the determination of pesticide residues in red wine samples.
Sample preparation involved extraction of pesticide residues into acetonitrile by QuEChERS (quick, easy, cheap, effective,
rugged and safe) and cleanup with a rapid pushthrough mini-cartridge filter instead of dispersive solid-phase extraction (dSPE).
The limit of detection (LOD) and limit of quantification (LOQ) were in the range of 0.01–0.40 and 0.05–1.33 ng/mL, respectively.
Six commercially available red wine samples were tested in this study, three of which were found to be positive for the presence
of pesticides.
KEY POINTS
|
Approximately, 26 billion litres of wine were produced worldwide and about 24 billion litres were consumed, according to the
International Organization of Vine and Wine, in 2010 (1). Wine, especially red wine, is a rich source of polyphenols such
as resveratrol, catechin and epicatechin. These polyphenolic compounds are antioxidants that protect cells from oxidative
damage caused by free radicals. Research on antioxidants found in red wine has shown that they may inhibit the development
of certain cancers such as prostate cancer (2). In addition, consumption of red wines has been believed to have heart-healthy
benefits (2). The application of pesticides such as fungicides and insecticides to improve grape yields is a common practice
in vineyards. However, the applied pesticides may permeate through plant tissues and remain in the harvested grapes and subsequent
processed products, such as grape juice and wine. Because pesticide residues are a potential source of toxic substances that
are harmful to human beings, it is important to test for the levels of pesticide residues in grapes, juice and wine. Although
the European Union (EU) has set maximum residue levels (MRLs) for pesticide residues in wine grapes of 0.01–10 mg/kg (3,4),
it has not yet established MRLs for wine. A study of 40 bottles of wine bought within the EU revealed that 34 of the 40 bottles
contained at least one pesticide. The average number of pesticides per bottle was more than four, while the highest number
of pesticides found in a single bottle was 10 (5).
The analysis of pesticide residues in red wine is challenging because of the complexity of the matrix, which contains alcohol,
organic acids, sugars, phenols and pigments (such as anthocyanins). Traditional red wine sample preparation methods include
liquid–liquid extraction (LLE) with different organic solvents (6,7) and solid-phase extraction (SPE) with reversed-phase
C18 and polymeric sorbents (8–10). However, LLE is labourintensive, consumes large amounts of organic solvents and sometimes
forms emulsions, making it difficult to separate the organic and aqueous phases. In contrast, SPE uses less solvent without
emulsion formation, but demands more effort for method development. Other methods such as solid-phase microextraction (SPME)
(11,12), hollow-fibre liquid-phase microextraction (13) and stir-bar sorptive extraction (SBSE) (14) use little or no organic
solvent but are less reproducible. Typical instrumental detections systems include gas chromatography (GC), GC coupled to
mass spectrometry (GC–MS) and liquid chromatography coupled to tandem mass spectrometry (LC–MS–MS) (6–14).
RSS
Bookstore
