Identification of pesticide poisoning in wildlife

Admission Causes, Morbidity, and Outcomes in Scavenger Birds in the North of Portugal (2005-2022)

Portugal is the habitat of three species of vultures. According to the IUCN Red List of Threatened Species, Neophron percnopterus is an Endangered species, Aegypius monachus is nearly Threatened, and Gyps fulvus is of Least Concern. This study aims to investigate the admission causes, morbidity, and outcomes of vultures admitted to a wildlife rehabilitation centre and necropsy service in Northern Portugal. Over 17 years (2005-2022), 84 animals were admitted: 10 A. monachus, 69 G. fulvus, and 5 N. percnopterus. The main causes of admission to the centre were 80% (n = 63) unknown cause, 13% (n = 10) found debilitated, 6 % (n = 5) vehicle collision, 4% (n = 3) captivity, 1% (n = 1) gunshot, and 1% (n = 1) electrocution. Most animals were admitted during the summer (45.2%) and autumn (36.9%). Analysis of outcome data showed that 73% (n = 58) of the animals that arrived alive at the centre could be rehabilitated and released back into the wild. Thirteen animals died during treatment and five were found dead. This is the first time that such a lengthy study of results and mortality has been carried out for these species in Portugal. Although the data are limited, they can already provide some information about these populations, particularly for the endangered species that are so rare to observe.

Use of poisoned baits against wildlife. A retrospective 17-year study in the natural environment of Extremadura (Spain)

This study reports the results obtained from toxicological analyses of different types of baits referred to the laboratory of the Toxicology Area (Faculty of Veterinary Medicine, Cáceres, Spain) over a 17-year period (2002-2018). These baits were suspicious materials found in the environment of the region of Extremadura (Western Spain), where such malpractices are a problem to be addressed, as wide livestock farming and hunting activities are combined with a significant wealth of wildlife (especially birds of prey). A total of 246 baits, including 32 commercial chemical products to be used in baits, were analysed. Samples from 183 cases were received and classified according to the material used for their preparation and the toxic substance found. Overall, the most common bait consisted of meat preparations (56.3% of cases) intended to eliminate predators considered 'annoying' for livestock and hunting practices, such as carnivores and scavengers. It should be noted that contact baits (as fenthion-impregnated perches) were also detected (7.6%). Regarding the substances detected, anticholinesterase compounds (organophosphates and carbamates) were the most commonly used substances for the preparation of baits (detected in 85.3% of positive baits). Moreover, 8% of the positive baits presented more than one toxic substance in their composition. Due to the types of toxic compounds and the methods used to prepare the baits, this study shows that the malicious use of highly toxic substances in the environment to kill wildlife is a common and current issue and poses a serious risk to different species.

Increasing incidence of barbiturate intoxication in avian scavengers and mammals in Spain

Pharmaceuticals are considered emerging contaminants in terms of impacts on wildlife. One chemical group of concern is euthanasia agents used in veterinary medicine. Here we present data on the occurrence of barbiturate intoxication using samples collected from 2004 to 2020 of suspected wildlife and domestic animal poisoning cases in Spain (n = 3210). Barbiturate intoxication was seen in 3.4% (45/1334) of the total number of confirmed intoxicated animals. Barbiturates were detected in 0.2% (1/448) of baits containing detectable poisons. The most frequently detected barbiturate was pentobarbital (42/45, 93.3%), but we also detected phenobarbital, barbital, and thiopental (2.2% prevalence for each). Avian scavengers were most frequently affected by barbiturate intoxication (n = 36), especially Eurasian griffon vultures (Gyps fulvus) (n = 28). Median pentobarbital concentrations detected in intoxicated griffon vultures was 27.3 mg kg^-1 in gastric content and 38.1 mg kg^-1 in liver, which highlights the acute effect of the chemical soon after ingestion. At least two large intoxication events affecting griffon vultures were related to the consumption of carcasses from euthanized livestock. We also found phenobarbital in a prepared bait linked to the intoxication of one Eurasian buzzard (Buteo buteo). This study highlights the need for stronger regulation of barbiturates to avoid secondary intoxications due to improper disposal of euthanized livestock.

Application and Evaluation of Novel Chromatographic Techniques to Detect and Quantitate 108 Pesticides and Metabolites in Muscle Samples From Wild Birds of Prey

The application and evaluation of highly efficient chromatographic techniques with tandem mass spectrometry for the detection and quantitation of 108 pesticides and metabolites, some considered persistent organic pollutants, was performed in muscle samples obtained from 25 birds of prey belonging to the families Accipitridae, Falconidae, and Strigidae presented dead in 2013 to Grupo de Rehabilitación de la Fauna Autóctona y su Hábitat, in Madrid, Spain. Pesticides with prohibited use were detected at high concentrations in the muscle samples analyzed. Based on its high sensitivity to detect pesticides in muscle, the described chromatographic techniques with tandem mass spectrometry should be considered an alternative testing methodology to those commonly used for routine application in ecotoxicological forensic research.

Micro QuEChERS-based method for the simultaneous biomonitoring in whole blood of 360 toxicologically relevant pollutants for wildlife

This work presents the optimization, validation, and verification of a miniaturized method for the determination of 360 environmental pollutants that are of toxicological concern for wildlife. The method implies a one-step QuEChERS-based extraction of 250 μl whole blood using acidified acetonitrile, followed by two complementary analyses by LC-MS/MS and GC-MS/MS. The optimized conditions allow the simultaneous determination of the major persistent organic pollutants, a wide range of plant protection products, rodenticides, pharmaceuticals, and a suite of metabolites that can be used as biomarkers of exposure. The method is very sensitive, and 95% of the pollutants can be detected at concentrations below 1.5 ng/ml. The method was applied to a series of 148 samples of nocturnal and diurnal wild raptors collected during field ecological studies in 2018 and 2019. Fifty-one different contaminants were found in these samples, with a median value of 7 contaminants per sample. As expected, five of the six contaminants that were detected in >50% of the samples were persistent or semi-persistent organic pollutants. However, it is striking the high frequency of detection of some non-persistent pollutants, such as 2-phenylphenol, benalaxyl, metaflumizone, diphenylamine, brodifacoum or levamisole, indicating the penetration of these chemicals into the food chains. The toxicological significance of all these findings should be studied in depth in future research. However, the results clearly demonstrated that the approach developed provides reliable, simple, and rapid determination of a wide range of pollutants in wildlife and makes it very useful to obtain valuable data in biomonitoring studies with only small amounts of sample.

The Usefulness of MS3 to Confirm Poisoning on the Example of Dog Poisoning with Strychnine

Strychnine is an alkaloid with strong toxic properties. Poisoning results in muscular contractions and death through asphyxiation. Intentional or accidental poisonings with strychnine occur mainly in small animals, especially dogs and occasionally cats. Strychnine can be detected in the liver or stomach contents. Unfortunately, the determination of strychnine in these matrices, especially in postmortem examination, is subject to a significant matrix effect that makes it difficult to confirm the presence of the substance being determined. Therefore, we developed a new liquid chromatography method combined with mass spectrometry. One-gram homogenized samples were extracted and partitioned after adding acetonitrile and 5-mol solution of ammonium acetate. After extraction, the samples were analyzed using high-pressure liquid chromatography-MS/MS/MS. The results of validation fulfil the requirement of the confirmatory criteria according to SANTE/11945/2015 regarding apparent recoveries (98.97% to 104.0%), repeatability (2.9%-4.1%), and within-laboratory reproducibility (3.3%-4.6%). The method can be successfully applied to confirm strychnine poisoning cases.

Plant-mediated RNAi of grain aphid CHS1 gene confers common wheat resistance against aphids

BACKGROUND

Chitin is an important component of the insect exoskeleton and peritrophic membrane. Chitin synthase 1 (CHS1) is a key enzyme in the chitin synthesis pathway, and has a role in insect molting and growth. Plant-mediated RNA interference (RNAi) has been used as a more target-specific and environmentally safe approach to prevent and control agricultural insects. The aims of this study were to use grain aphid (Sitobion avanae) CHS1 as the target gene and to produce transgenic wheat lines for aphid control via plant-mediated RNAi.

RESULTS

Expression levels of CHS1 changed at different developmental stages. After feeding on the representative T₃ transgenic lines Tb5-2 and Tb10-3, CHS1 expression levels in grain aphid decreased by 50.29% and 45.32%, respectively; and total and molting aphid numbers reduced significantly, compared with controls. Consistent with this, aphid numbers in mixed natural populations reduced significantly in the respective T₄ and T₅ transgenic lines under field conditions, and T5 transgenic lines had higher grain weight compared with the unsprayed insecticide wild-type and insecticide-sprayed wild-type.

CONCLUSION

These results indicate that plant-mediated RNAi of the grain aphid CHS1 gene confers common wheat resistance against aphids. © 2018 Society of Chemical Industry.

Development of an Analytical Procedure for the Determination of Multiclass Compounds for Forensic Veterinary Toxicology

Reported here is a new analytical multiclass method based on QuEChERS technique, which has proven to be effective in diagnosing fatal poisoning cases in animals. This method has been developed for the determination of analytes in liver samples comprising rodenticides, carbamate and organophosphorus pesticides, coccidiostats and mycotoxins. The procedure entails addition of acetonitrile and sodium acetate to 2 g of homogenized liver sample. The mixture was shaken intensively and centrifuged for phase separation, which was followed by an organic phase transfer into a tube containing sorbents (PSA and C18) and magnesium sulfate, then it was centrifuged, the supernatant was filtered and analyzed by liquid chromatography tandem mass spectrometry. A validation of the procedure was performed. Repeatability variation coefficients <15% have been achieved for most of the analyzed substances. Analytical conditions allowed for a successful separation of variety of poisons with the typical screening detection limit at ≤10 μg/kg levels. The method was used to investigate more than 100 animals poisoning incidents and proved that is useful to be used in animal forensic toxicology cases.

Multiresidue method for trace pesticide analysis in honeybee wax comb by GC-QqQ-MS

The aim of this analytical study is to develop an improved multi-residue methodology of high sensitivity and expanded scope for pesticide residue analysis in honeybee wax combs. The method was validated for 160 pesticide residues (including acaricides, insecticides, fungicides and herbicides) gas chromatography amenable and covering a wide variety of polarity and chemical structure. This method of analysis applied gas chromatography coupled to a triple quadrupole mass spectrometer for the quantitative analysis of pesticide residues. The extraction procedure applied was based QuEChERs method allowing acceptable recoveries for most of the pesticides (98%), within the range 60-120% with an associated precision (RSD) <20%, at concentration levels of MQL of 10µgkg^-1 for all pesticides with the exception of 3,5-dichloroaniline and chlordane (20µgkg^-1). The expanded uncertainty of the results was ±35% on average (coverage factor k=2 for a confidence level of 95%). The chromatographic multi-residue method was applied to determine levels of pesticide residues in 50 honeybee wax comb samples randomly collected from different apiaries in Spain. A total of 32 pesticide residues (14 insecticides/acaricides, 10 insecticides, 6 fungicides and 2 herbicides) were detected in the samples. The highest pesticide concentrations were found for those with insecticide-acaricide activity like acrinathrin, chlorfenvinphos, coumaphos and fluvalinate-tau, some of them are mainly applied in apiculture for controlling the honeybee parasite Varroa destructor. The total load of pesticide residues ranged from 69 to 1000µgkg^-1 for 40% of the analysed samples, 22% contained pesticide residues in the ranges of 1000-2000µgkg^-1, 24% between 2000 and 5000µgkg^-1 and 14% of the samples contained residues between 5000 and 9557µgkg^-1.

Epidemiology of animal poisoning: An overview on the features and spatio-temporal distribution of the phenomenon in the north-eastern Italian regions

In the present paper we analyze and discuss about the records referring to animal poisonings and poisoned baits cases covering the period between 2007 and 2013 and submitted for diagnostic investigations to the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), which is the public veterinary health institute competent for the north eastern Italian regions. All data were gathered by a passive surveillance system based on voluntary reporting, which became mandatory in 2009 after a decree of the Italian Ministry of Health had come into force. This prohibited the use and detention of poisoned baits and ordered to selected institutions and professionals to carry out standardized surveys to assess suspect and/or confirmed reported cases; all the necessary anatomopathological and toxicological investigations to confirm the reported cases were then performed for free by public veterinary health institutes whenever a veterinarian diagnosis or clinical suspicion were provided. Totally, 1831 suspected animals poisoning and 698 cases of supposed poisoned baits recovery episodes were registered. 642/1831 (35.1%) animal poisoning cases were confirmed and the presence of toxic agents was verified in 292/698 baits (41.8%). The most severely affected territories were the ones with the highest level of urbanization and those most densely populated in the study area. Dogs and cats seemed to be greatly affected by poisoning cases and a characteristic seasonal trend was noticed, with an increase of episodes in late Winter/early Spring and in Autumn. Carbamate insecticides resulted to be the main cause for animal poisoning, while anticoagulants rodenticides played a primary role among toxicants found in poisoned baits. The presented results emphasize that malicious animal poisoning is a widespread problem in north-eastern Italy. The still relevant number of reported poisoning events caused by some banned pesticides poses the problem of identifying where these substances come from and brings to light the popular knowledge about the high toxicity of these compounds. Moreover, the noticeable increase of the number of episodes registered in 2009 pointed out how the above mentioned decree may have contributed to reveal a number of hidden cases which had not been investigated before, probably due to economic reasons related to the costs of toxicological analyses.

Analysis of Insecticides in Dead Wild Birds in Korea from 2010 to 2013

Wild birds are exposed to insecticides in a variety of ways, at different dose levels and via multiple routes, including ingestion of contaminated food items, and dermal, inhalation, preening, and embryonic exposure. Most poisoning by insecticides occurs as a result of misuse or accidental exposure, but intentional killing of unwanted animals also occurs. In this study, we investigated insecticides in the gastric contents of dead wild birds that were suspected to have died from insecticide poisoning based on necropsy. The wild birds were found dead in various regions and locations such as in mountains, and agricultural and urban areas. A total of 182 dead wild birds of 27 species were analyzed in this study, and insecticide residue levels were determined in 60.4% of the total samples analyzed. Monocrotophos and phosphamidon were the most common insecticides identified at rates of 50.0% and 30.7% of the insecticide-positive samples, respectively. Other insecticides identified in dead wild birds included organophosphorous, organochlorine and carbamate insecticides. However, there was limited evidence to conclusively establish the cause of death related to insecticides in this study. Nevertheless, considering the level of insecticide exposure, it is speculated that the exposure was mainly a result of accidental or intentional killing, and not from environmental residue.

Risk assessment of bearded vulture (Gypaetus barbatus) exposure to topical antiparasitics used in livestock within an ecotoxicovigilance framework

Between 2004 and 2013, 486 suspected scavenger poisoning cases, including 24 bearded vultures (Gypaetus barbatus), were investigated in the Pyrenees and surrounding areas in Spain as part of a monitoring programme regarding accidental and intentional poisoning of wildlife. Poisoning was confirmed in 36% of all analysed cases where scavenger species were found dead within the distribution range of bearded vultures. Organophosphates and carbamates were the most frequently detected poisons. Four of the bearded vulture cases were positive for the presence of topical antiparasitics (3 with diazinon and 1 with permethrin). These likely represented accidental exposure due to the legal use of these veterinary pharmaceuticals. In order to confirm the risk of exposure to topical antiparasitics in bearded vultures, pig feet (n=24) and lamb feet (n=24) were analysed as these are one of the main food resources provided to bearded vultures at supplementary feeding stations. Pig feet had no detectable residues of topical antiparasitics. In contrast, 71.4% of lamb feet showed residues of antiparasitics including diazinon (64.3%), pirimiphos-methyl (25.4%), chlorpyrifos (7.1%), fenthion (1.6%), permethrin (0.8%) and cypermethrin (27.8%). Washing the feet with water significantly reduced levels of these topical antiparasitics, as such, this should be a recommended practice for lamb feet supplied at feeding stations for bearded vultures. Although the detected levels of antiparasitics were relatively low (≤1 μg/g), a risk assessment suggests that observed diazinon levels may affect brain acetylcholinesterase and thermoregulation in bearded vultures subject to chronic exposure.

Silencing of an aphid carboxylesterase gene by use of plant-mediated RNAi impairs Sitobion avenae tolerance of Phoxim insecticides

RNA interference (RNAi) describes the ability of double-stranded RNA (dsRNA) to inhibit homologous gene expression at the RNA level. Its specificity is sequence-based and depends on the sequence of one strand of the dsRNA corresponding to part or all of a specific gene transcript. In this study we adopted plant-mediated RNAi technology that targets Sitobion avenae (S. avenae) to enable gene silencing in the aphid and to minimize handling of the insects during experiments. S. avenae was selected for this study because it causes serious economic losses to wheat throughout the world. The carboxylesterase (CbE E4) gene in S. avenae was homologously cloned, which increased synthesis of a protein known to be critical to the resistance (tolerance) this species has developed to a wide range of pesticides. A plant RNAi vector was constructed, and transgenic Triticum aestivum (dsCbE1-5 and dsCbE2-2 lines) expressing CbE E4 dsRNA were developed. S. avenae were fed on dsCbE1-5 and dsCbE2-2 lines stably producing the CbE E4 dsRNA. CbE E4 gene expression in S. avenae was reduced by up to 30-60%. The number of aphids raised on dsCbE1-5 and dsCbE2-2 was lower than the number raised on non-transgenic plants. A solution of CbE E4 enzyme from S. avenae fed on dsCbE1-5 and dsCbE2-2 plants hydrolyzed only up to 20-30% Phoxim solution within 40 min whereas a solution of the enzyme from CbE E4 fed on control plants hydrolyzed 60% of Phoxim solution within 40 min. CbE E4 gene silencing was achieved by our wheat-mediated RNAi approach. This plant-mediated RNAi approach for addressing degradation-based pesticide resistance mechanisms in aphids and may prove useful in pest management for diverse agro-ecosystems.

Validation and application of multi-residue analysis of eight anticoagulant rodenticides by high-performance liquid chromatography with fluorimetric detection

Poisoning of domestic animals is frequently caused by anticoagulant rodenticides. Validation and applications of a rapid and reliable method for the simultaneous determination of 8 anticoagulant rodenticides (bromadiolone, brodifacoum, coumachlor, coumafuryl, coumatetralyl, difenacoum, flocoumafen, and warfarin) in baits and animal livers using high-performance liquid chromatography with fluorescence detection are reported herein. The methodology was validated by an in-house validation model at 2.5 mg/kg, which is the level commonly found in the tissues of poisoned domestic animals. The 8 anticoagulants can be determined at the concentration range of 1.25-100 mg/kg with determination coefficients higher than 0.992. A recovery value from 70% to 109% was observed for all the studied molecules. The results of the validation process demonstrate suitability for application in official analysis and for monitoring purposes of animal poisoning by anticoagulant rodenticides.

Residues and dissipation dynamics of molluscicide metaldehyde in cabbage and soil

The dissipation of metaldehyde on cabbage and in soil was studied and half-life (DT(50)) was estimated in a field study carried out at three different locations. Metaldehyde was sprayed on cabbage at 937.5 and 1406.25 ga.i.ha(-1) for residue study and 1,875 ga.i.ha(-1) for dissipation study in cabbage and soil. Samples of cabbage and soil for dissipation experiment were collected at 0, 1, 2, 3, 5, 7, 14 and 21 days after treatment. For residue studies, cabbage and soil samples were sampled at 5, 7 and 10 days after treatment. Quantification of residues was done by LC-MS/MS. The DT(50) of metaldehyde in cabbage and soil were 0.48-1.61 days and 0.75-1.02 days, respectively, when applied at 2 times of the recommended high dosage. Residues of metaldehyde in cabbage were all below the maximum residue levels of 1.0 mg kg(-1) at both recommended high dosage and 1.5 times the recommended high dosage.

Analysis of molluscicide metaldehyde in vegetables by dispersive solid-phase extraction and liquid chromatography-tandem mass spectrometry

This paper describes the development and validation of a new reverse-phase liquid chromatography-electrospray ionisation tandem mass spectrometric method (RP-HPLC-ESI-MS/MS) for the determination of metaldehyde in different kinds of vegetables. Metaldehyde was extracted with 20 ml acetonitrile from 10 g vegetable and followed by dispersive solid-phase extraction (Bondesil-primary secondary amine, PSA). The identification of metaldehyde was established by chromatographic retention times, analyte-specific fragmentation patterns and relative peak area ratios of two precursor/product ion pairs. The limit of detection of this method was 0.01 mg kg(-1) using an injection volume of 5 µl. The repeatability of this method is excellent and the relative standard deviation (RSD) is less than 4%.

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.

Pesticides and the intoxication of wild animals

Pesticides are widely used to control agricultural pests. Unfortunately, because of their biological activity, they may have detrimental effects on nontarget species. Acute toxicity, resulting in death, is reported worldwide. Although chronic and indirect effects may be even more hazardous for animal populations on a long-term basis, they are usually evaluated as parts of research programs. The purpose of this paper was to review the wildlife-poisoning surveillance systems and their results regarding the circumstances of exposure of wild animals, the pesticides involved and the species exposed. Most data are retrieved from the British and French pesticide poisoning surveillance systems in wildlife, with some data from other European structures.

Comparison study of the extraction methods of paraquat in post-mortem human blood samples

The most important step for Paraquat analysis in post-mortem human blood (PMB) is its extraction from the specimens, as Paraquat is insoluble in organic solvents due to its ionic form. The most common extraction method, solid phase extraction (SPE), has been used for the extraction of Paraquat from PMB. However, SPE procedures are somewhat time-consuming, and resulted in unsatisfactory recovery in our laboratory. Therefore, SPE procedures, with five extraction solvents for the liquid-liquid extraction (LLE) of paraquat in PMB, were compared using HPLC, and the chloroform-ethanol (7:3, v/v) solvent mixture was found to be the most effective. The recoveries of Paraquat using the 7:3 solvent mixture in human whole blood samples, which were already spiked with paraquat standards (1.05, 2.10 and 4.21 microg/mL) averaged 98.20, 105.71 and 99.40%, but the recoveries from the SPE were about 74.29, 78.50 and 80.10%, respectively. Linearity was obtained for the range of Paraquat standards, with a correlation coefficient; r2 > 0.999. The limit of detection (LOD, with S/N > or =3) and limit of quantitation (LOQ, with S/N > or =10) were 0.01 and 0.05 microg/mL, respectively. The extraction method was successfully applied to seven real post-mortem cases involving paraquat poisoning.

Expression and characterization of carboxylesterase E4 gene from peach-potato aphid (Myzus persicae) for degradation of carbaryl and malathion

An abridged carboxylesterase E4 (CbE E4) gene was cloned from the peach-potato aphid, Myzus persicae, by reverse transcription-PCR and subcloned into the expression vector pET28b. The abridged CbE E4 gene was successfully expressed in E. coli BL21 (DE3). The recombinant CbE E4 hydrolyzed beta-naphthyl acetate and Carbaryl by 64% within 2.5 h, Malathion by 80% within 1.25 h. However, the hydrolysis of other pesticides (Dichlorovos, Parathion, Pirimicarb and Deltamethrin) was not detected.

Mortality of globally threatened Sarus cranes Grus antigon from monocrotophos poisoning in India

Globally threatened Sarus cranes Grus antigon are resident at Keoladeo National Park World Heritage site and the surrounding area near Bharatpur, Western Rajasthan, India. In winter, they are joined by c. 200 wintering common cranes Grus grus. On 23 November 2000, 15 Sarus cranes and three common cranes were found dead in a field adjacent to the park, where wheat seed had been sown the previous day. Chemical analyses of seed samples from the field and the cranes' alimentary tract contents identified residues of the organophosphate insecticide monocrotophos. Monocrotophos concentrations of 0.8 and 1.8 ppm were found in wheat samples, and 0.2-0.74 ppm (x=0.33) in the alimentary tract contents of five of the seven cranes examined. No other organophosphate or organochlorine pesticides were detected. We conclude that the cranes died from monocrotophos poisoning after eating treated seed. We discuss similar incidents of avian mortality, and recommend that measures be taken to reduce these.

Determination of chloralose residues in animal tissues by liquid chromatography-electrospray ionisation tandem mass spectrometry

A relatively rapid and specific method for the determination of chloralose in animal tissues by LCMSMS was developed. Isocratic reverse phase HPLC was used to introduce samples for electrospray negative ionisation tandem mass spectrometry. Methanol extracts were diluted to approximate the mobile phase composition, then filtered prior to analysis. Residues were identified by monitoring the multiple reaction monitoring (MRM) transitions of precursor ions mass:charge (m/z) 309 and 307 to a common m/z 161 product ion. Qualitative and quantitative confirmation data were acquired simultaneously by monitoring alternative MRM transitions. Calibration was linear over a working range of 0.025-1.3 microg/ml, and the limit of quantitation (LOQ) was 0.28 mg/kg for liver. The mean recovery was 88.5% from chicken muscle tissue fortified at 198-237 mg/kg, and ranged from 81.3 to 94.3% from liver tissue fortified at 1-52 mg/kg. The method is compared to a gas chromatography (GC) procedure previously employed.

Analytical methods for pesticide residue determination in bee products

Monitoring pesticide residues in honey, wax, and bees helps to assess the potential risk of these products to consumer health and gives information on the pesticide treatments that have been used on the field crops surrounding the hives. The present review seeks to discuss the basic principles and recent developments in pesticide analysis in bee products and their application in monitoring programs. Consideration is given to extraction, cleanup, chromatographic separation, and detection techniques.

Organochlorine pesticides in wolves from Galicia

Levels of seven organochlorine pesticides (heptachlorepoxide, dieldrin, endrin, p,p'-DDE, o-p'-DDT, p,p'-DDT, and methoxychlor) and DDE/DDT ratios were determined in spleen, liver, muscle, kidney and suprarenal from 12 wolves from three provinces of Galicia (eight male and four female). Analysis was carried out by GC-ECD. Heptachlorepoxide was in found only 25% of samples, while p,p'-DDE was the most dominant of the organochlorine compounds analyzed. DDE/DDT ratios higher than 1 were found in liver and muscle.

Determination of metaldehyde in suspected cases of animal poisoning using gas chromatography-ion trap mass spectrometry

A method was developed to detect the molluscicide metaldehyde in samples of stomach contents for forensic toxicology investigations. Gas chromatography-ion trap mass spectrometry in full-scan mode was used to identify and quantify metaldehyde. The limit of detection based on mass chromatograms for the m/z 89 ion was 3 microg/g. Mean recoveries from six different spiked samples were 74% at 25 microg/g and 94% at 500 microg/g. The relative standard deviation of six replicate determinations of a sample containing 632 microg/g metaldehyde was 7.3%.

Mortality incident in northern bald ibis Geronticus eremita in Morocco in May 1996

In May 1996 there was an acute and dramatic mortality incident in the last remaining wild population of northern bald ibis Geronticus eremita. This species is Critically Endangered, comprising only about 250 wild individuals, which occur on the Atlantic coast of southern Morocco. Over a period of 10 days a total of 38 adult birds (aged 1 year or more) died or disappeared. Deaths, probably secondary to the loss of one or both parent birds, also occurred subsequently in six estlings and one recent fledgling. The incident appeared to involve no other species. This paper describes the pattern of the incident, and pathological, microbiological and toxicological investigations and findings. Several features point to a toxic aetiology but the cause of the incident has not been established.

On-line sample preparation of paraquat in human serum samples using high-performance liquid chromatography with column switching

A new ion-pair high-performance liquid chromatographic method with column-switching has been developed for the determination of paraquat in human serum samples. The diluted serum sample was injected onto a precolumn packed with LiChroprep RP-8 (25-40 microm) and polar serum components were washed out by 3% acetonitrile in 0.05 M phosphate buffer (pH 2.0) containing 5 mM sodium octanesulfonate. After valve switching to inject position, concentrated compounds were eluted in the back-flush mode and separated on an Inertsil ODS-2 column with 17% acetonitrile in 0.05 M phosphate buffer (pH 2.0) containing 10 mM sodium octanesulfonate. The total analysis time per sample was about 30 min and mean recovery was 98.5+/-2.8% with a linear range of 0.1-100 microg/ml. This method has been successfully applied to serum samples from incidents by paraquat poisoning.