Pendimethalin residues in onion

By using capillary gas chromatography we checked the amount of pendimethalin residues in a new onion and a ripe onion bulb, after its application in the recommended quantity on four various agro-ecological localities. The experiment was set on the following localities: Subotica (soil type carbonate chernozem on less plate), Novi Knezevac (swampy greasy black soil), Kisac (average carbonate chemozem) and Srbobran (carbonate chernozem). For the onion bulb production seeding was performed in optimal time, during March, with 80 kg of seed/ha (variety Stutgarter Riesen), with the application of the preparation Stomp 330 E in the quantity of 5 dm(3)/ha. Samples for the analysis were taken twice from a new onion and a ripe onion bulb. After the extraction and cleaning up, using SPLC Si column, the pendimethalin content was determined by gas chromatography with ECD, while the presence was proved through mass spectrometry. The least average pendimethalin residues were found in the onion bred in Kisac (0.095 mg/kg), and the greatest in the onion from Srbobran (0.296 mg/kg).