UHPLC-DAD method for the determination of neonicotinoid insecticides in single bees and its relevance in honeybee colony loss investigations

Abstract

In the understanding of colony loss phenomena, a worldwide crisis of honeybee colonies which has serious consequences for both apiculture and bee-pollination-dependent farm production, analytical chemistry can play an important role. For instance, rapid and accurate analytical procedures are currently required to better assess the effects of neonicotinoid insecticides on honeybee health. Since their introduction in agriculture, neonicotinoid insecticides have been blamed for being highly toxic to honeybees, possibly at the nanogram per bee level or lower. As a consequence, most of the analytical methods recently optimized have focused on the analysis of ultratraces of neonicotinoids using liquid chromatography-mass spectrometry techniques to study the effects of sublethal doses. However, recent evidences on two novel routes-seedling guttations and seed coating particulate, both associated with corn crops-that may expose honeybees to huge amounts of neonicotinoids in the field, with instantly lethal effects, suggest that selected procedures need optimizing. In the present work, a simplified ultra-high-performance liquid chromatography-diode-array detection method for the determination of neonicotinoids in single bees has been optimized and validated. The method ensures good selectivity, good accuracy, and adequate detection limits, which make it suitable for the purpose, while maintaining its ability to evaluate exposure variability of individual bees. It has been successfully applied to the analysis of bees in free flight over an experimental sowing field, with the bees therefore being exposed to seed coating particulate released by the pneumatic drilling machine.

Study on Soil Mobility of Two Neonicotinoid Insecticides

“…High performance liquid chromatographic (HPLC) applications are preferred especially for aqueous samples, as removal of water (i.e., extraction of target compounds with an organic solvent) and/or chemical transformation can be omitted prior to measurement. For detection of neonicotinoids UV [22], diode array detector (DAD) [23,24] or mass spectrometry [25,26] are suitable. Determination of these ingredients from complex matrices (e.g., foods) requires more complicated sample preparation, as the coextracted substances often interfere with target compounds; thus clean-up cannot be omitted and selective detection mode (e.g., LCMS/MS) is necessary.…”

Methiocarb metabolites are systemically distributed throughout corn plants grown from coated seeds

“…Large-scale worldwide use of neonicotinoid insecticides in recent decades (Bonmatin et al 2015;Giorio et al 2017) was found to impact the health of honeybees and wild pollinators (Tapparo et al 2012(Tapparo et al , 2013Wood and Goulson 2017;Pisa et al 2017), aquatic species (Gibbons et al 2015;Pisa et al 2015), birds, and mammals (Gibbons et al 2015) including humans (Ichikawa et al 2019). Despite being introduced as a safe and more environmentally friendly approach, the seed coating application of these systemic insecticides did not prevent their release into soil, ground and surface waters, in guttation drops, and into the air (through dust emitted during sowing) (Tapparo et al 2012;Bonmatin et al 2015;Giorio et al 2017;Hitaj et al 2020).…”

Fast Determination of Thiacloprid by Photoinduced Chemiluminescence

“…It is a relatively new pesticide (patent 1985) 1 , which is a disruptor of the nervous system by acting as an inhibitor at nicotinic acetylcholine receptors found in many insects 2 . The possible relationship between neonicotinoid pesticides and massive disappearance of honeybees from the hive is a topic of great interest nowadays [3][4] .…”