Pesticide determination in rose concrete and rose absolute using dispersive‐solid phase extraction followed by gas chromatography‐tandem mass spectrometry

Abstract The rose species Rosa damascena and Rosa centifolia are cultivated for their use as perfume raw materials. The solvent extract of rose petals provides the concrete that is further transformed into the absolute. Both, concrete and absolute contain a variety of organic molecules. As a result of the lack of an adequate analytical procedure and the complexity of the matrices, the accurate quantification of pesticides in concrete and absolute remains challenging. Here we describe the first analytical method to quantify 57 pesticide residues in rose concrete and 56 pesticide residues in rose absolute. The method uses a multistep dispersive‐solid phase extraction (d‐SPE) cleanup followed by injection in a gas chromatography‐tandem mass spectrometer. Sample preparation includes the extraction of analytes from the matrix using acetonitrile and a mixture of salts and a double clean‐up step using sorbents in the form of primary and secondary amines (PSA), magnesium sulphate, C18 and graphitized carbon black (GCB). Two fortification levels, 0.025 to 0.15 and 0.5 mg/kg, were assessed. For 56 pesticides, the obtained recoveries were within the range of 70% to 120 % with a relative standard deviation (RSD) lower than 20% at each spiked level. The validation parameters proved that the developed method can be used for the quantification of 57 pesticide residues in rose concrete and 56 pesticide residues in rose absolute with a limit of quantification (LOQ) ranging from 0.025 to 0.1 mg/kg in concrete and from 0.05 to 0.15 mg/kg in absolute, depending on the active substance. Copyright © 2015 John Wiley & Sons, Ltd.