HPLC-MS/MS method for analysis of isoproturon in difficult matrix: poppy seeds

Abstract

While several validated methods have been developed for analysis of phenylurea herbicides in staple food plants, analytical procedures suitable for their quantification in minor crops such as poppy seeds are not available. For the registration of isoproturon use in this crop, the documentation of dynamics of its residues following treatment was requested. To accomplish this task, HPLC-MS/MS method was developed. Extraction of residues was realised by methanol-water mixture, Supelclean LC-18 SPE cartridges were used for purification of crude extracts. For HPLC separation of isoproturon SPE fraction Lichrospher C18 column (25 cm × 4 mm, 5 μm) was employed. For detection and quantification of target analyte, mass spectrometer with ion trap analyser operated in positive atmospheric pressure chemical ionisation (APCI) and MS/MS mode was used. Following performance parameters of method were obtained: detection limit 0.01 mg/kg, recovery 84%, and repeatability 7%.