Comparison of Two Methods for the Determination of Selected Pesticides in Honey and Honeybee Samples

Enhancing knowledge of chemical exposures and fate in honey bee hives: Insights from colony structure and interactions

Honey bees are unintentionally exposed to a wide range of chemicals through various routes in their natural environment, yet research on the cumulative effects of multi-chemical and sublethal exposures on important caste members, including the queen bee and brood, is still in its infancy. The hive's social structure and food-sharing (trophallaxis) practices are important aspects to consider when identifying primary and secondary exposure pathways for residential hive members and possible chemical reservoirs within the colony. Secondary exposures may also occur through chemical transfer (maternal offloading) to the brood and by contact through possible chemical diffusion from wax cells to all hive members. The lack of research on peer-to-peer exposures to contaminants and their metabolites may be in part due to the limitations in sensitive analytical techniques for monitoring chemical fate and dispersion. Combined application of automated honey bee monitoring and modern chemical trace analysis techniques could offer rapid progress in quantifying chemical transfer and accumulation within the hive environment and developing effective mitigation strategies for toxic chemical co-exposures. To enhance the understanding of chemical fate and toxicity within the entire colony, it is crucial to consider both the intricate interactions among hive members and the potential synergistic effects arising from combinations of chemical and their metabolites.

The role of the veterinary diagnostic toxicologist in apiary health

Susceptibility of individuals and groups to toxicants depends on complex interactions involving the host, environment, and other exposures. Apiary diagnostic investigation and honey bee health are truly population medicine: the colony is the patient. Here we provide basic information on the application of toxicology to the testing of domestic honey bees, and, in light of recent research, expand on some of the challenges of interpreting analytical chemistry findings as they pertain to hive health. The hive is an efficiently organized system of wax cells used to store brood, honey, and bee bread, and is protected by the bee-procured antimicrobial compound propolis. Toxicants can affect individual workers outside or inside the hive, with disease processes that range from acute to chronic and subclinical to lethal. Toxicants can impact brood and contaminate honey, bee bread, and structural wax. We provide an overview of important natural and synthetic toxicants to which honey bees are exposed; behavioral, husbandry, and external environmental factors influencing exposure; short- and long-term impacts of toxicant exposure on individual bee and colony health; and the convergent impacts of stress, nutrition, infectious disease, and toxicant exposures on colony health. Current and potential future toxicology testing options are included. Common contaminants in apiary products consumed or used by humans (honey, wax, pollen), their sources, and the potential need for product testing are also noted.

Contamination of Honeybee (Apis mellifera L.) Royal Jelly by Pesticides and Sample Preparation Methods for Its Determination: A Critical Appraisal

Pesticides can easily enter the food chain, harming bee populations and ecosystems. Exposure of beehive products to various contaminants has been identified as one of the factors contributing to the decline in bee populations, and multiple food alerts have been reported. Despite this fact, royal jelly, a valuable bee product with nutritional and functional properties, has received less attention in this context. Pesticide residues of different chemical class can contaminate royal jelly when foraging bees collect pollen or nectar from pesticide-treated flowers, or in some cases, due to its frequent and inappropriate use in the treatment of mites in beehives. To monitor this issue and also make it more reliable, it is crucial to develop effective sample preparation methods for extracting pesticides from royal jelly for subsequent analysis. In this context, this review provides information about sample preparation methods (solid-phase extraction, solvent extraction, and QuEChERS-quick, easy, cheap, effective, rugged and safe) and analytical methods that have been validated or improved to extract and analyze pesticides, respectively, in royal jelly samples of different origins. Finally, future perspectives are discussed. With this background, we aim to provide data that can guide future research related to this topic.

A global study of pesticides in bees: QuEChERS as a sample preparation methodology for their analysis - Critical review and perspective

To this day, it remains unknown what the cause of decline of honey bee populations is and how to prevent this phenomenon efficiently. Poisonings with pesticides are assumed to be among the main causes for the decline of the honey bee population. Despite the significant progress observed in analytics over recent years, research aimed at improving methods applied in diagnostics of bee poisoning is still in progress. This is no easy task, since determination of the content of trace amounts (often equal to sublethal doses) of a wide range of compounds with diverse physico-chemical properties in honey bee samples with a complex matrix composition poses a serious challenge to modern analytics. This overview is the first to include a comprehensive critical assessment of analytical methods proposed for quantification of pesticides in honey bees over the last decade. Since the QuEChERS method is currently of great significance to ensuring accurate and reliable results of pesticide quantification in honey bees, the present overview focuses on the major aspects of this method, which will provide a comprehensive reference for scientists. The review focuses on the limitations of methods and on potential future prospects. It also contains information on the detection of pesticides in honey bees between 2010 and 2020 and characterizes the pesticide classes which are most toxic to these insects. This is extremely important, not just in the context of understanding the potential adverse impact of pesticides, manifesting as losses in bee colonies; it is also intended to facilitate decision-making in future research related to this difficult yet very important subject.

Determination of DDT in honey samples by liquid-liquid extraction with low-temperature purification (LLE-LTP) combined to HPLC-DAD

Honey is widely consumed worldwide, however, this food can be contaminated by chemical contaminants, such as the insecticide dichlorodiphenyltrichloroethane (DDT). Despite legal restrictions on DDT use, this organochlorine pesticide has been detected in honey collected in several developed and developing countries, representing risks to human health, animals, and the environment due to its high environmental persistence, potential carcinogenicity, and ecotoxicological effects. Thus, the development of an analytical method for DDT monitoring in this matrix is important to ensure food security. Therefore, this study aimed to optimize and validate a simple, low-cost, and efficient method using the liquid-liquid extraction with low-temperature purification (LLE-LTP) to determine DDT in honey samples by high-performance liquid chromatography with diode array detector (HPLC-DAD). The proposed method was validated according to SANTE guidelines, being considered selective, precise, accurate, and linear in the range of 8.0-160 μg kg^-1. The limits of detection (LOD) and quantification (LOQ) achieved were 4.0 and 8.0 μg kg^-1, respectively. This LOQ value is lower than the maximum residue limit established by the Brazilian and European Union legislation. Therefore, the LLE-LTP combined to HPLC-DAD allows the routine analysis of DDT in honey samples and can be widely applied in studies to monitor this pesticide, especially in developing countries, where DDT use is still allowed.

Optimization of Method for Pesticide Detection in Honey by Using Liquid and Gas Chromatography Coupled with Mass Spectrometric Detection

This study aimed to optimize and validate a multi-residue method for identifying and quantifying pesticides in honey by using both gas and liquid chromatographic separation followed by mass spectrometric detection. The proposed method was validated to detect 168 compounds, 127 of them by LC-MS/MS (liquid chromatography tandem mass spectrometric detection) and 41 by GC-MS/MS (gas chromatography tandem mass spectrometric detection). The limit of detection (LOD) and limit of quantification (LOQ) values for the analytes determined by LC-MS/MS were 0.0001–0.0004 mg/kg and 0.0002–0.0008 mg/kg, respectively. For GC-MS/MS analyses, the LOD and LOQ values were 0.001–0.004 mg/kg and 0.002–0.008 mg/kg. In total, 33 samples of commercial honey produced by apiaries in six Brazilian states were analyzed with the validated method. Residual amounts of 15 analytes were detected in 31 samples (93.9%). The method described in the present study was able to detect an extensive and broad range of pesticides with very high sensitivity.

Development and validation of a new method for the simultaneous determination of spinetoram J and L in honey from different botanical origins employing solid-phase extraction with a polymeric sorbent and liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

The objective of this study was to propose a novel method to determine residues of the bio-insecticide spinetoram, which is a mixture of two components (spinetoram J and L), in honey from multifloral, rosemary and heather botanical origins; liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was the technique employed. An efficient sample treatment (recoveries between 82% and 95%) involving a solid-phase extraction with a polymeric sorbent has been recommended, and no matrix effect was observed. Chromatographic analysis (4 min) was performed in reverse phase mode by using a fused-core column (Kinetex® EVO C₁₈) with acetonitrile and ammonium formate as the mobile phase components, which was applied in isocratic elution mode. Method was validated according to the current European legislation. Not only was it selective, but it also displayed a wide linear range, good precision (relative standard deviation values lower than 9%) and sensitivity (low limits of detection (spinetoram J, 0.1-0.3 μg/kg; spinetoram L, 0.1-0.2 μg/kg) and quantification (spinetoram J, 0.3-1.2 μg/kg; spinetoram L, 0.4-0.7 μg/kg)). Several honey samples were analyzed with this method and no spinetoram residues were found above the limits of detection.

Evaluation of Pesticide Residues in Vegetables from the Asir Region, Saudi Arabia

This study’s aim was to determine the pesticide residues in 10 different vegetable commodities from the Asir region, Saudi Arabia. We evaluated 211 vegetable samples, collected from supermarkets between March 2018 and September 2018, for a total of 80 different pesticides using ultrahigh-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) and gas chromatography–tandem mass spectrometry (GC-MS/MS) after extraction with a multi-residue method (the QuEChERS method). The results were assessed according to the maximum residue limit (MRL) provided by European regulations for each pesticide in each commodity. All lettuce, cauliflower, and carrot samples were found to be free from pesticide residues. A total of 145 samples (68.7%) contained detectable pesticide residues at or lower than MRLs, and 44 samples (20.9%) contained detectable pesticide residues above MRLs. MRL values were exceeded most often in chili pepper (14 samples) and cucumber (10 samples). Methomyl, imidacloprid, metalaxyl, and cyproconazole were the most frequently detected pesticides. Based on the results of this study, we recommend that a government-supported program for the monitoring of pesticide residues in vegetables be established to promote consumers’ health and achieve sustainable farming systems.