Ion chromatography coupled to Q-Orbitrap for the analysis of formic and oxalic acid in beehive matrices: a field study.

There is an increasing concern about the use of synthetic acaricides to fight the ectoparasitic mite Varroa destructor. Natural products such as formic acid (FA) and oxalic acid (OA) have emerged as a possible alternative control strategy. However, given the difficulty of analysing these highly polar compounds and the lack of robust and reliable methods, there are very few studies of the concentration and distribution of these natural acaricides in the beehive compartments. We present a reliable and simple analytical methodology, based on sample extraction with modified quick polar pesticide (QuPPe) methods followed by ion chromatography coupled to a quadrupole Orbitrap mass analyser for the analysis of FA and OA in honeybees, honey, beeswax, and beebread. The developed methods have been used in a field study for the evaluation of the presence and distribution of FA and OA in the beehive products, as well as in adult bees and bee brood samples, before, during, and up to 3 months after the application of the treatments by the beekeeper. Beebread and honey samples presented the highest concentration levels of OA and FA, respectively, mainly due to their natural presence. As expected, the organic acids showed low persistence in wax after the treatments. The natural acaricides were found in adult and developing bees at concentration levels below the reported LD50 in all the cases; however, residue levels of OA in larvae during the treatment application were very close to the reported LD50.

Multi-residue screening of non-polar hazardous chemicals in green turtle blood from different foraging regions of the Great Barrier Reef.

Green turtles spend a large part of their lifecycle foraging in nearshore seagrass habitats, which are often in close proximity to sources of anthropogenic contaminants. As most biomonitoring studies focus on a limited number of targeted chemical groups, this study was designed to screen for a wider range of hazardous chemicals that may not have been considered in prior studies. Whole blood of sub-adult green turtles (Chelonia mydas) were sampled from three different locations, a remote, offshore 'control' site; and two coastal 'case' sites influenced by urban and agricultural activities on the Great Barrier Reef in North Queensland, Australia. In order to screen blood samples for chemicals across a wide range of KOW's, a modified QuEChER's extraction method was used. The samples were analysed using a multi-residue gas chromatography with tandem mass spectrometry system (GC-MS/MS method that allowed simultaneous quantification of polychlorinated biphenyls (PCBs), polychlorinated diphenyl ethers (PBDES), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs). While PBDEs, PCBs and OCPS were below the limits of quantification, PAHs were detected in all turtle blood samples. However, PAH levels were relatively low (maximum ΣPAH = 13 ng/mL ww) and comparable to or less than those reported from other green turtles globally. The present study provides the first baseline PAH levels in blood samples from green turtles from nearshore and offshore locations in the Southern Hemisphere.