Determination of the phenoxyacid herbicides MCPA, mecoprop and 2,4-D in kidney tissue using liquid chromatography with electrospray tandem mass spectrometry.

An analytical method was developed to determine the phenoxyacid herbicides 2,4-D, MCPA and mecoprop in kidney tissue from animals where poisoning is suspected. Samples were Soxhlet extracted using diethyl ether and the extracts cleaned-up using anion exchange solid phase extraction cartridges. Analysis was performed using liquid chromatography with negative-ion electrospray tandem mass spectrometry (LC-MS/MS). The method was evaluated by analysing control kidney samples fortified at 1 and 5 mg/kg. Mean recoveries ranged from 82 to 93% with relative standard deviations from 3.2 to 19%. The limit of detection was estimated to be 0.02 mg/kg.

Incidents of bee poisoning with pesticides in the United Kingdom, 1994-2003.

For over 20 years, the UK Agriculture Departments have monitored the direct effects of pesticides on beneficial insects, mainly honeybees (Apis mellifera, L.) and bumblebees (Bombus terrestris, L.), as part of the Wildlife Incident Investigation Scheme (WIIS). The Central Science Laboratory (CSL) has contributed to WIIS by providing the required laboratory skills for the determination of bee diseases and the expert analytical experience necessary to determine low-level pesticide residues and interpret these results. The results from WIIS form part of the pesticide regulatory process coordinated by the Pesticides Safety Directorate (PSD) and are published each year. This paper has reviewed the data from WIIS over the 10 year period from 1994 to 2003. The overall trend is that suspected poisoning incidents, reported by beekeepers and the general public, have declined from 56 incidents per year to 23 incidents per year. The number of these incidents that have been attributed to pesticide poisoning has also declined, from 25 incidents to five incidents per year. The possible reasons for these changes and the circumstances involved in the bee poisoning incidents are discussed. However, the source of the pesticide in bee poisoning incidents is often uncertain and the likely cause of these incidents and any trends over time are also discussed.

Determination of imidazole and triazole fungicide residues in honeybees using gas chromatography-mass spectrometry.

An analytical method employing clean up by high-performance gel permeation chromatography (HPGPC) and solid-phase extraction (SPE) on Florisil cartridges was developed to determine residues of eleven imidazole and triazole ergosterol-biosynthesis-inhibiting (EBI) fungicides in honeybee samples. Detection was by means of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. The method was validated by fortifying control samples at levels of 0.01 and 0.05 micro g/bee. Mean recoveries for each analyte except imazalil were between 79 and 99% with relative standard deviations of 12.3% or less. Mean recoveries of imazalil were 51% at 0.01 micro g/bee and 81% at 0.05 micro g/bee. Limits of detection for the analytes investigated ranged from 0.005 to 0.001 micro g/bee.

Development of a cell culture/ELISA assay to detect anticoagulant rodenticides and its application to analysis of rodenticide treated grain.

This study describes a generic biological screening assay designed to detect anticoagulant rodenticides based on their inhibitory action on the vitamin K epoxide reductase protein complex, resulting in an accumulation of under-carboxylated prothrombin or proteins induced by vitamin K antagonism (PIVKA-II). A combined cell culture/ELISA assay was optimized to measure PIVKA-II production by the human hepatoma HepG2 cell line cultured in the presence of anticoagulant rodenticides. The specificity and sensitivity of the assay was validated using 41 grain extracts containing representative concentrations of rodenticide or appropriate nonrodenticide control compounds. In all cases, PIVKA-II produced by HepG2 cells in response to grain extracts spiked with rodenticides was detected by ELISA, while PIVKA-II was not detected in supernatants collected from cells exposed to nonrodenticide controls. This represents a novel, class-specific biological assay for the detection of anticoagulant rodenticides present in contaminated grain.

Analytical methods used in the United Kingdom Wildlife Incident Investigation Scheme for the detection of animal poisoning by pesticides.

The United Kingdom Wildlife Incident Investigation Scheme (WIIS) investigates cases of suspected poisoning of wildlife, honey bees, and companion animals by pesticides. Together with field inquiries and veterinary post-mortem examinations, the analytical procedures presented here provide a comprehensive approach to the investigation of these cases. The paper covers selection of animal tissues for analysis and methods suitable for the analysis of honey bees and for various types of bait. Seven multiresidue methods cover around 130 pesticides, and methods are also described for a further 8 compounds. These methods are currently used on samples submitted to the Scheme in England and Wales.

Stratospheric memory and skill of extended-range weather forecasts.

We use an empirical statistical model to demonstrate significant skill in making extended-range forecasts of the monthly-mean Arctic Oscillation (AO). Forecast skill derives from persistent circulation anomalies in the lowermost stratosphere and is greatest during boreal winter. A comparison to the Southern Hemisphere provides evidence that both the time scale and predictability of the AO depend on the presence of persistent circulation anomalies just above the tropopause. These circulation anomalies most likely affect the troposphere through changes to waves in the upper troposphere, which induce surface pressure changes that correspond to the AO.