Utveckling av analysmetoder och screening av växtskyddsmedel i bin och pollen

Honey bees (Apis mellifera) and pollen combs were collected from 14 bee communities in eight different regions in the south of Sweden during May/June and July 2012, resulting in 28 bee samples and 26 pollen samples in total. Analytical multimethods based on liquid chromatography connected to tandem mass spectrometry (LC-MS/MS) and gas chromatography connected to mass spectrometry (GC-MS) were developed and covered 78 and 21 different pesticides, respectively. The detection limits differed significantly between compounds and typically ranged between 0.01 and 2 ng/g bee or pollen. In total, 21 different pesticides were detected in bee samples and 26 pesticides in pollen samples. The majority of the findings were in the low analytical range close to the detection or quantification limits for the compounds. Up to 13 pesticides were detected in a single bee sample and up to 16 pesticides in a single pollen sample. The highest measured concentrations were for the fungicides prochloraz with 407 ng/g in pollen and azoxystrobin with 309 ng/g in pollen and 42 ng/g in bees. The neonicotinoid insecticides acetamiprid, clothianidin and thiacloprid were detected in both bee and pollen samples at low ng/g levels. The most frequently detected neonicotinoid was thiacloprid that was found in ten bee samples and six pollen samples. With regard to both frequency and concentration levels the sampling locations in the south and central part of the Skåne region dominated. Also, the samples collected in the May/June shift dominated in these aspects over the samples collected in July. The described methods can be used to determine pesticide exposure to bee communities as well as to screen for terrestrial exposure in the agricultural environment. The methods can be adapted to single bee analysis, thus enabling analysis of wild bee populations, and to very small amounts of pollen if needed.