Residue distribution and risk assessment of two macrocyclic lactone insecticides in green onion using micro-liquid-liquid extraction (MLLE) technique coupled with liquid chromatography tandem mass spectrometry

Dissipation and dietary exposure risk assessment of spinosad, thiocyclam, and its metabolite nereistoxin in cucumber and groundwater for different population groups

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) technique using ultrahigh-performance liquid chromatography with tandem mass spectrometry for the analysis of spinosad (spinosyn A + spinosyn D), thiocyclam, and nereistoxin in cucumber was developed with mean recoveries of 93-104%, relative standard deviations of ≤9%, and limits of quantification of 0.01 mg/kg. Field trials of spinosad and thiocyclam were performed in 12 representative cultivating areas in China. Field trial results indicate that spinosyn A and spinosyn D easily dissipated in cucumber with half-lives of 2.48-6.24 and <3 days, respectively. Nereistoxin was produced after thiocyclam application and was more persistent than its parent. The terminal residues of spinosad were all below the maximum residue limits (0.2 mg/kg) in China, whereas the terminal concentration of nereistoxin (calculated as the stoichiometric equivalent of thiocyclam), which was much higher than that of thiocyclam, was far beyond the maximum residue limits of thiocyclam in cucumber (0.01 mg/kg) established by the European Union. The predicted no-effect concentrations of spinosyn A, spinosyn D, thiocyclam, and nereistoxin leaching into groundwater were estimated using China-PEARL (Pesticide Emission Assessment at Regional and Local scales) models after application. However, the dietary (food and water) exposure risk quotient for different populations was below 1 with a preharvest interval set at 5 days after the last application, indicating that the application of spinosad and thiocyclam in cucumber was unlikely to pose unacceptable risk for human health. This study provides data for the safe use of spinosad and thiocyclam in cucumber ecosystem.

Terminal Residues and Risk Assessment of Spiromesifen and Spirodiclofen in Tomato Fruits

Insecticides are important to increase crop yields, but their overuse has damaged the environment and endangered human health. In this study, residues of spiromesifen and spirodiclofen were determined in tomato fruit using a simple and efficient analytical procedure based on acetonitrile extraction, extract dilution, and UPLC-MS/MS. The linearity range was 1-100 µg/kg and 0.5-100 µg/kg, and the correlation coefficient (R²) and residuals were ≥0.9991 and ≤16.4%, respectively. The limit of determination (LOD) was 0.26 and 0.08 µg/kg, while the limit of quantification (LOQ) was verified at 5 µg/kg. The relative standard deviation of spiked replicates at 5 µg/kg analyzed in one day (RSDr, n = 6) was ≤8.35%, and within three different days (RSDR, n = 18) it was ≤15.85%, with recoveries exceeding 91.34%. The method recovery test showed a satisfactory value of 89.23-97.22% with an RSD of less than 12.88%. The matrix effect was determined after a 4-fold dilution of the raw extract and was -9.8% and -7.2%, respectively. The validated method was used to study the dissipation behavior of the tested analytes in tomato fruit under field conditions. First-order kinetics best described the dissipation rates. The calculated half-lives were 1.49-1.83 and 1.91-2.38 days for spiromesifen and spirodiclofen, respectively, after application of the authorized and doubled authorized doses, indicating that spiromesifen dissipated more rapidly than spirodiclofen. The final residue concentrations of spiromesifen and spirodiclofen were 0.307-0.751 mg/kg and 0.101-0.398 mg/kg, respectively, after two or three applications, and were below the European Union (EU) maximum residue limits. The chronic risk assessment indicates that both insecticides are safe for adult consumers.

Dissipation kinetics and exposure of spirotetramat and pymetrozine in open fields, a prelude to risk assessment of green bean consumption

Determination and dissipation kinetics of pymetrozine and spirotetramat in green bean were studied using a QuEChERS method coupled to high-performance liquid chromatography-tandem mass spectrometry. Pymetrozine recoveries ranged between 88.4-93.7%, with relative standard deviation (RSD) of 5.5-14.4%. For spirotetramat the recoveries ranged between 91.7-103.4%, and the RSD were in the range of 3.2 to 12.4%. The limits of quantification (LOQs) were 0.01 mg/kg and 0.005 mg/kg for pymetrozine and spirotetramat, respectively.The developed analytical method was used to study the degradation rates of pymetrozine and spirotetramat in green bean grown in open field. Results showed that pymetrozine and spirotetramat followed the first-order kinetics model with half-lives of 3.3 days and 4.2 days, respectively. Furthermore, risk assessment was carried out which showed that, the chronic risk quotient (RQc) values for pymetrozine and spirotetramat were much lower than 100%. The present results indicated that the health risks posed for consumers by the pymetrozine and spirotetramat residues were negligible at the recommended dosages.

Health-promoting foods and food crops of West-Africa origin: The bioactive compounds and immunomodulating potential

The rural communities of the sub-Sahara regions in Africa are rich in diverse indigenous culinary knowledge and foods, food crops, and condiments such as roots/tubers, cereal, legumes/pulses, locust beans, and green leafy vegetables. These food crops are rich in micronutrients and phytochemicals, which have the potentials to address hidden hunger as well as promote health when consumed. Some examples of these are fermented foods such as ogi and plants such as Vernonia amygdalina (bitter leaf), Zingiber officinales (garlic), Hibiscus sabdariffa (Roselle), and condiments. Food crops from West Africa contain numerous bioactive substances such as saponins, alkaloids, tannins, phenolics, flavonoids, and monoterpenoid chemicals among others. These bioresources have proven biological and pharmacological activities due to diverse mechanisms of action such as immunomodulatory, anti-inflammatory, antipyretic, and antioxidant activities which made them suitable as candidates for nutraceuticals and pharma foods. This review seeks to explore the different processes such as fermentation applied during food preparation and food crops of West-African origin with health-promoting benefits. The different bioactive compounds present in such food or food crops are discussed extensively as well as the diverse application, especially regarding respiratory diseases. PRACTICAL APPLICATIONS: The plants and herbs summarized here are more easily accessible and affordable by therapists and others having a passion for promising medicinal properties of African-origin plants.The mechanisms and unique metabolic potentials of African food crops discussed in this article will promote their applicability as a template molecule for novel drug discoveries in treatment strategies for emerging diseases. This compilation of antiviral plants will help clinicians and researchers bring new preventive strategies in combating COVID-19 like viral diseases, ultimately saving millions of affected people.

Quantitative and rapid detection of spinosad and spinetoram by a gold nanoparticle-based immunostrip

Spinosad (SPI) and spinetoram (Et-SPI) are currently among the most popular new insecticides because of their high efficiency and low toxicity. However, excessive residues in food still pose a potential risk to public health. Therefore, it is necessary to strengthen residue monitoring of the two insecticides based on a simple and rapid method. In this study, a highly sensitive mAb (6G9) against SPI and Et-SPI was prepared using the hapten SPI-HS and used to develop a colloidal gold nanoparticle-based immunochromatographic strip for the detection of SPI and Et-SPI in samples. The quantitative ranges of the developed strip for SPI and Et-SPI were 8.93-1633 ng g^-1 and 20.3-3555 ng g^-1 in rice, 32.6-785 ng g^-1 and 79.3-1862 ng g^-1 in tea, and 9.66-360 ng g^-1 and 23.9-931 ng g^-1 in onions, respectively. In addition, recovery rates ranged from 85.7% to 112.7% with a coefficient of variation <9.5%. Therefore, our developed method was sensitive and valid as a quantitative tool for the rapid monitoring of SPI and Et-SPI in foods.

Dissipation and residue analysis of novel nematicide trifluorocide in ginseng and soil using modified QuEChERS method coupled with HPLC-MS/MS

In the present study, an analytical method that combined a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method and high-performance liquid chromatography coupled with tandem mass spectrometry was developed to determine trifluorocide in fresh and dried ginseng roots, plants (stems and leaves), and soil. At three spiked levels (0.01, 0.1, and 1.0 mg kg^-1), the mean recoveries (n = 15) of trifluorocide from fresh and dried ginseng roots, plants, and soil were in the range of 95.6 - 109.7%, with relative standard deviations less than 10.0%. The limits of quantitation of different matrices were determined to be 0.01 mg kg^-1. Dissipation and residue study of trifluorocide was conducted in ginseng cultivation ecosystems in Northeast China. The t_1/2 (half-life) of trifluorocide in ginseng fresh roots, plants, and soil were 8.3-13.1 days, 7.4-10.9 days, and 8.8-10.6 days, respectively. The terminal residues of trifluorocide in ginseng fresh roots were less than 0.01 mg kg^-1 after 35 days of trifluorocide application. This study could be beneficial in residue analysis and assist in the scientific application of trifluorocide during ginseng cultivation.

Recent Advances in Bioactive Compounds, Health Functions, and Safety Concerns of Onion (Allium cepa L.)

Onion (Allium cepa L.) is a common vegetable, widely consumed all over the world. Onion contains diverse phytochemicals, including organosulfur compounds, phenolic compounds, polysaccharides, and saponins. The phenolic and sulfur-containing compounds, including onionin A, cysteine sulfoxides, quercetin, and quercetin glucosides, are the major bioactive constituents of onion. Accumulated studies have revealed that onion and its bioactive compounds possess various health functions, such as antioxidant, antimicrobial, anti-inflammatory, anti-obesity, anti-diabetic, anticancer, cardiovascular protective, neuroprotective, hepatorenal protective, respiratory protective, digestive system protective, reproductive protective, and immunomodulatory properties. Herein, the main bioactive compounds in onion are summarized, followed by intensively discussing its major health functions as well as relevant molecular mechanisms. Moreover, the potential safety concerns about onion contamination and the ways to mitigate these issues are also discussed. We hope that this paper can attract broader attention to onion and its bioactive compounds, which are promising ingredients in the development of functional foods and nutraceuticals for preventing and managing certain chronic diseases.

Residue behavior and dietary risk assessment of spinetoram (XDE-175-J/L) and its two metabolites in cauliflower using QuEChERS method coupled with UPLC-MS/MS

Spinetoram (XDE-175-J/L), a new spinosyn-based insecticide, is one of the most widely used bio-pesticide worldwide and its registration for direct application on cauliflower to control Plutella xylostella is currently under review in China. In this study, an accredited method for simultaneous determination of spinetoram and its two metabolites in cauliflower was established and validated using QuEChERS (quick, easy, cheap, effective, rugged, and safe) preparation coupled with ultra-liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The average recoveries using this method were ranged from 74 to 99% with relative standard deviations (RSDs) of 2.4-10.5%. The dissipation kinetics and terminal residues of spinetoram and its two metabolites in cauliflower were studied in Tianjin and Guizhou over two years under open field conditions. The dissipation experiments revealed that spinetoram was swiftly degraded in cauliflower, with the half-lives less than or equal to 4.85 days. The terminal residues of total spinetoram (sum of spinetoram and its two metabolites) detected in cauliflower samples were in the range of 0.009 mg/kg-0.337 mg/kg. Dietary risk assessment study was implemented based on the scientific data of field trials, food consumption and acceptable daily intake (ADI). The estimated long-term dietary risk probability (RQ) of total spinetoram from cauliflower was between 5.79% and 5.91%, indicating that spinetoram was associated with acceptable risk for dietary cauliflower consumption. The results would provide scientific guidance for proper usage of spinetoram in cauliflower field ecosystem.

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.