In this study, we have applied, for the first time, dissociation
extraction in a water-free medium as a sample treatment strategy
for high-effective complete extraction of pesticide residues of
conazole group class from rapeseed oil. The proposed methodology
was combined with gas chromatography with electron capture
detection for quantitation of pesticide residues at limits of quantitation
ranged from 3.0 to 300 lg kg1
. The obtained detection limits
are below the maximum residue levels (MRLs) set by the
European Union for the majority of pesticides. Dissociation extraction
offers various attractive advantages compared with ordinary
solvent extraction. It provides remarkably higher recoveries while
using the same amount of extractant or allows consuming much
less volume of solvent to achieve the same recoveries of azole pesticides.
The clean-up procedure by hexane from acidified water–
acetonitrile mixture with following neutralization and purification
step with aqueous solution of dipotassium hydrogen orthophosphate
provides removing of acids and hydrophilic substances from
extract. The application of this sample preparation strategy,
undoubtedly, could be extended to other kinds of vegetable oils
and other pesticides with basic properties.