Extraction method for sample preparation from apples for gas chromatographic determination of tebufenpyrad residues
Distribution of tebufenpyrad between n-hexane and aqueous solutions of organic solvents has been studied at 20 ± 1 °С in systems hexane - acetonitrile - water and hexane - methanol - water. Based on the obtained experimental data on tebufen-pyrad distribution, the sample preparation extraction method has been and proposed for tebufenpyrad determination in apples by gas chromatography. This method provides chromatograms without interfering peaks, is characterized by 95% extraction of tebufenpyrad and 4% standard deviation. The gas chromatographic protocol for determination tebufenpyrad has been developed for application. The protocol allows to determine tebufenpyrad at concentrations 6 times below the maximum residue level in apples for EU countries and provides high accuracy and reproducibility.