Acetonitrile-Ethyl acetate based method for the residue analysis of 373 pesticides in beeswax using LC-MS/MS and GC-MS/MS

Evaluation of environmental contamination in beeswax products

Beeswaxes are used as a coating agent or as a wrapping material for food products making them potentially ingested by consumers. There is no regulation yet in Europe giving maximum levels of contaminants in this type of product. Nevertheless, being a natural product, they are exposed to environmental pollution, thus it appears necessary to establish their contamination rate in order to evaluate potential human exposure. In this study, a method of extraction of different environmental contaminants including pesticides, phthalates, PAHs and phenols was developed. Based on a hot Soxhlet extraction, followed by cleaning steps, the method was validated for the quantitation of the cited contaminants by LC-MS/MS and GC-(MS)/MS. Three different types of waxes were analyzed including typical white waxes (Cera Alba) and yellow waxes (Cera Flava). It was shown that all waxes had the presence of at least one contaminant and that phthalates, in particular DEHP, was present in all beeswax samples. Insecticides were found in majority among all the classes of pesticides screened. The yellow waxes were found to be contaminated with the highest rates of PAHs (60%), pesticides (75%) and phenols (40%). The detection frequency of PAHs, in contrast to phthalates, was the lowest for all the types of waxes combined.

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.

Establishment of a modified QuEChERS extraction and liquid chromatography-tandem mass spectrometry method for multiple pesticide residues followed by determination of the residue levels and exposure assessment in livestock urine

The establishment of an analytical method for pesticide residues in livestock urine can realize the real-time monitoring of pesticide pollution in livestock breeding. In this study, a novel method was developed for the determination of 106 pesticide residues in livestock urine based on a modified QuEChERS extraction and liquid chromatography-tandem mass spectrometry. Acetonitrile was used to extract target analytes through acidic and alkaline switching of the sample environment. The purification effect of captiva EMR-Lipid on samples was investigated. Three kinds of materials, C18, polar enhanced polymer (PEP), N-propylethylenediamine (PSA), were selected from 20 kinds of materials as adsorbents for QuEChERS. A mass analysis was carried out using simultaneous scanning in both positive and negative ion mode and multiple reaction monitoring mode. All analytes showed good linearity, with correlation coefficients (R2) greater than 0.9923; their limits of quantification were 0.02-1.95 ng/mL. The average recoveries at low, medium, and high spiked levels were in the range of 70.1 %-117.3 %, with intra-day precision ranging from 3.4 % to 16.9 % and inter-day precision ranging from 4.0 % to 19.3 %. The established analytical method was used to analyze the pesticide residue in swine urine and bovine urine collected from farms in Yining, Xinjiang, China. A total of 8 pesticides were detected, and the residue ranged from less than the limit of quantitation to 22.4 ng/mL. The top three pesticides with the highest detection frequency were clothianidin, thiamethoxam, and dinotefuran. The exposure assessment based on the monitored pesticide residue concentration levels showed that the detected pesticides could pose little risk to cattle and pigs.

Ternary solvent based homogeneous liquid-liquid microextraction for the preconcentration of organochlorine pesticides from water and apple juice samples

In the present study, the optimal experimental conditions were determined by optimizing the effect of extraction solvent types and volume, salt types and concentration, centrifugation speed and time using one variable at a time. Under optimal experimental conditions, calibration curves were constructed separately using water and apple juice samples as representative matrices, and good linearities were achieved over a wide concentration range of 0.2-1600 ng L-1 with a coefficient of determination (r2) ≥ 0.998. The limits of detection (LOD) and limits of quantification (LOQ), determined to be 3 and 10 times the signal-to-noise ratios (S/N), were between 0.07-3.9 and 0.2-12.0 ng L-1 for water samples and 2.6-10.0 and 8.0-30.0 ng L-1 for the apple juice sample respectively. The precisions study showed %RSD values of ≤6% for both matrices, indicating satisfactory precisions. The enrichment factors and recoveries of the proposed method ranged from 41.4-74.5 and 86-109% respectively. The proposed method could be used as a simple and environmentally friendly alternative for the analysis of OCPs from environmental and food matrices. This method potentially offers a more sustainable and effective approach to monitoring OCPs in environmental and food products. Its use in the analysis of apple juice samples is particularly novel and can provide valuable insights into pesticide contamination in fruit juices.

Pesticide contamination of beeswax from managed honey bee colonies in New York State

The New York State (NYS) beekeeping industry generated >$11M worth of honey in 2020 and >$300M in pollination services to agriculture annually. Bees are frequently exposed to pesticides through foraging and husbandry practices. Lipophilic pesticides can remain in beeswax for extended periods. We analyzed for pesticides in wax comb samples collected from NYS apiaries at the end of the growing season, comparing residue numbers and concentrations among beekeepers of different operation scales: commercial beekeepers (>300 colonies), sideliners (50-299 colonies), and hobbyists (<50 colonies). We analyzed samples collected from 72 managed honey bee colonies for 92 insecticides, herbicides, and fungicides by liquid chromatography-tandem mass spectrometry. Pesticides were detected in all samples and included 34 fungicides, 33 insecticides, and 22 herbicides. Each wax sample contained 7-35 different residues (x¯ = 17.8 residues). Wax from colonies managed by commercial beekeepers contained the most residues (x¯ = 21.9 residues), hobbyists were second (x¯ = 16.3 residues), and sideliners had the fewest (x¯ = 11.7 residues). Nearly all wax samples (98.6%) contained the pesticide synergist piperonyl butoxide, most samples (86%) contained common varroacides used to control honey bee parasites, including coumaphos and amitraz breakdown products, and 93.1% contained the fungicide difenoconazole. We detected 34 fungicides, 7 of which were found in 50% or more of the samples. We detected 22 herbicides. We found pesticide contamination of beeswax to be common, with commercial beekeepers experiencing the greatest contamination.

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.

Simultaneous analytical method for 296 pesticide multiresidues in root and rhizome based herbal medicines with GC-MS/MS

A method for the simultaneous analysis of pesticide multiresidues in three root/rhizome-based herbal medicines (Cnidium officinale, Rehmannia glutinosa, and Paeonia lactiflora) was developed with GC-MS/MS. To determine the concentrations of pesticide residues, 5 g of dried samples were saturated with distilled water, extracted with 10 mL of 0.1% formic acid in acetonitrile/ethyl acetate (7:3, v/v), and then partitioned using magnesium sulfate and sodium chloride. The organic layer was purified with Oasis PRiME HLB plus light, followed by a cleanup with dispersive solid-phase extraction containing alumina. The sample was then injected into GC-MS/MS (2 μL) using a pulsed injection mode at 15 psi and analyzed using multiple reaction monitoring (MRM) modes. The limit of quantitation for the 296 target pesticides was within 0.002-0.05 mg/kg. Among them, 77.7-88.5% showed recoveries between 70% and 120% with relative standard deviations (RSDs) ≤20% at fortified levels of 0.01, and 0.05 mg/kg. The analytical method was successfully applied to real herbal samples obtained from commercial markets, and 10 pesticides were quantitatively determined from these samples.

Pesticide residues in bee bread, propolis, beeswax and royal jelly - A review of the literature and dietary risk assessment

Due to pollinator decline observed worldwide, many studies have been conducted on the pesticide residue content of apicultural products including bee bread, propolis, beeswax and royal jelly. These products are consumed for their nutraceutical properties, although, little information is available on the human health risk posed by pesticides present in them. In our research, studies dealing with the pesticide contamination of the above-mentioned hive products are reviewed. Dietary exposures were calculated based on the recommended daily intake values and concentration data reported by scientific studies. Potential acute and chronic health risk of consumers were evaluated by comparing the exposure values with health-based guidance values. Available data indicate that a wide range of pesticide residues, especially acaricides may accumulate in bee bread, propolis and beeswax, up to concentration levels of more thousand μg/kg. Based on our observations, tau-fluvalinate, coumaphos, chlorfenvinphos, chlorpyrifos and amitraz are commonly detected pesticide active substances in beehive products. Our estimates suggest that coumaphos and chlorfenvinphos can accumulate in beeswax to an extent that pose a potential health risk to the consumers of comb honey. However, it appears that pesticide residues do not transfer to royal jelly, presumably due to the filtering activity of nurse bees during secretion.

Biosensing Chlorpyrifos in Environmental Water Samples by a Newly Developed Carbon Nanoparticle-Based Indirect Lateral Flow Assay

Pesticides are used in agriculture to prevent pests. Chlorpyrifos (CHLP) is an insecticide with potentially detrimental effects on humans, bees, and the aquatic environment. Its effects have led to a total ban by the European Union (EU), but outside the EU, CHLP is still produced and used. An indirect lateral flow immunoassay (LFIA) for the detection of CHLP was developed and integrated into a cassette to create a lateral flow device (LFD). Species-specific reporter antibodies were coupled to carbon nanoparticles to create a detector conjugate. Water samples were mixed with a specific CHLP monoclonal antibody and detector conjugate and applied to the LFD. Dose-response curves elicited the detection of low concentrations of CHLP (<1 µg/L). This sensitivity was recorded through a rapid handheld digital imaging device but also visually by naked eye. The CHLP LFD was applied to a range of European surface water samples, fortified with CHLP, revealing a sensitivity in these matrices of 2 µg/L, both by digital and visual analysis. To improve the simplicity of the CHLP LFIA, the assay reagents were dried in tubes, enabling to carry out the test by simply adding water samples and inserting the LFIA strips. This CHLP LFIA is thus suited for the on-site screening of surface waters.

Comprehensive Strategy for Sample Preparation for the Analysis of Food Contaminants and Residues by GC-MS/MS: A Review of Recent Research Trends

Food safety and quality have been gaining increasing attention in recent years. Gas chromatography coupled to tandem mass spectrometry (GC-MS/MS), a highly sensitive technique, is gradually being preferred to GC-MS in food safety laboratories since it provides a greater degree of separation on contaminants. In the analysis of food contaminants, sample preparation steps are crucial. The extraction of multiple target analytes simultaneously has become a new trend. Thus, multi-residue analytical methods, such as QuEChERs and adsorption extraction, are fast, simple, cheap, effective, robust, and safe. The number of microorganic contaminants has been increasing worldwide in recent years and are considered contaminants of emerging concern. High separation in MS/MS might be, in certain cases, favored to sample preparation selectivity. The ideal sample extraction procedure and purification method should take into account the contaminants of interest. Moreover, these methods should cooperate with high-resolution MS, and other sensitive full scan MSs that can produce a more comprehensive detection of contaminants in foods. In this review, we discuss the most recent trends in preparation methods for highly effective detection and analysis of food contaminants, which can be considered tools in the control of food quality and safety.

A Complementary, Quantitative and Confirmatory Method to UHPLC/ESI Q-Orbitrap Screening based on UPHLC/ESI-MS/MS for Analysis of 416 Pesticides in Fruits and Vegetables

BACKGROUND

Triple quadrupole (MS/MS) and high-resolution mass spectrometer (HRMS), coupled with ultra-high performance liquid chromatography (UHPLC) or gas chromatography (GC), are technologies used to analyse pesticide residues in fruits and vegetables. LC-MS/MS has been the gold standard for analysis of pesticides, offering reliable performance and sensitivity, while LC-HRMS is expanding in applications to serve as another benchmark. Method development and testing scope expansion are constantly required with new generation mass spectrometers.

OBJECTIVE

This paper discusses the development and validation of a quantitative and confirmatory method that can analyse over 400 pesticide residues using state-of-the-art UHPLC/ESI-MS/MS system.

METHOD

Homogenized fruit and vegetable samples were fortified with pesticides and were extracted using a modified QuEChERS method. Samples were injected onto a UHPLC/ESI-MS/MS system, and data were acquired in multiple reaction monitoring mode. The method was validated using a nested experimental design, and was able to quantify and confirm 416 pesticide in fruits and vegetables. It was also complimentary to the UHPLC/ESI Q-Orbitrap quantitative and screening methods previously developed in the authors' laboratory.

RESULTS

The method demonstrated good performance. In all matrices, 92% of pesticides yielded recoveries between 81-110%, more than 95% of pesticides yielded intermediate precision ≤ 20%, and about 65% of pesticides yielded measurement uncertainties ≤ 20%, and 96% of pesticides yielded measurement uncertainties ≤ 50%.

HIGHLIGHTS

This method was developed using the same mobile phases, analytical columns, and extraction procedure, as UHPLC/ESI Q-Orbitrap methods. Extracts can be run on either system, streamlining monitoring programs and offering high sample throughput.

Highly-selective complex matrices removal via a modified QuEChERS for determination of triazine herbicide residues and risk assessment in bivalves

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERs) method for determining triazine herbicide residues in bivalves (Mussels, Scallops, Cockles) was developed. The use of molecularly imprinted polymers (MIPs) as a selective purification material during dispersive-solid phase extraction (d-SPE) increased the removal rate of pigments interference. With 4% acidic acetonitrile as the organic modifier, the modified QuEChERs method achieved good extraction rate of herbicide residues. The satisfactory recoveries (80%-118%) and RSDs (1.0%-11.6%) of herbicide residues were obtained at three spiked levels. The limits of quantification of herbicide residues ranged from 0.10 μg/kg to 1.59 μg/kg. Further, the herbicide residues in bivalves collected in the eastern coasts of China was analyzed. The developed QuEChERs procedure coupled with GC-MS/MS was successfully applied to the herbicide residues detection in bivalves, and due to the extensive use of herbicides and the large consumption of bivalves in globally, the ongoing risk evaluation is needed.