Quick, Easy, Cheap, Effective, Rugged, And Safe Research Articles

Analysing multi-class pesticide residues in tilapia fish: development and validation of LC-MS/MS and GC-MS/MS methods

ABSTRACT Pesticides are an integral part of increasing food production and have remarkable agricultural benefits such as an increase in crop yield. However, they have been identified as some of the most hazardous substances in food, particularly in fish, posing a risk to both ecosystems and human health. Therefore, this study focuses on the development and optimisation of an analytical technique to detect multiple pesticide residues in fish products. The method involves liquid-liquid extraction, followed by analysis using both liquid and gas chromatography coupled with mass spectrometry. A total of 411 pesticides were selected (e.g.: insecticides, fungicides, and herbicides) and the concentrations of their residues in tilapia (Oreochromis niloticus) were determined. The samples were processed according to the optimised QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, including extraction and clean-up procedures. Lipid co-extracts were successfully minimised before instrumental analysis using optimised cleanup. Matrix-matched calibrations were performed at two different levels (0.05,0.01 mg/kg) in tilapia fish to compensate for signal enhancement/suppression. The validation procedure was performed to assess accuracy, precision, limit of quantification (LOQ), and uncertainty according to the SANTE guidelines. The LOQs of this method were 0.01 mg/kg for all selected pesticides except Cyazofamid, Dodine, Fenpyrazamine, Methomyl, Oxadiargyl, Parathion ethyl, Parathion methyl, Prothioconazole Desthio, and Tolylfluanid were 0.05 mg/kg. The suggested method was implemented to investigate the levels of pesticide residues in fresh fish samples (n = 15) procured from local markets in Egypt. Only two samples had residues of the targeted analytes. In light of our findings, the devised methodology was effectively utilised for the detecting and measurement of pesticide residues present in fish samples.

Ecological risk assessment of organochlorine pesticide residues in sediment samples from Lake Tana and Hayqe in Northwest Ethiopia

In most developing countries, including Ethiopia, the excessive use of toxic and persistent pesticides for agricultural and malaria control purposes poses a significant challenge. This study focuses on evaluating the concentration and ecological risks associated with organochlorine pesticides (OCPs) in the sediments of Lake Tana and Hayqe. Employing a laboratory-based cross-sectional approach, the residues of OCPs in sediment samples were extracted using the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method, followed by dispersive solid phase extraction cleanup (d-SPE) techniques and analyzed for 18 OCPs by gas chromatography coupled to tandem mass spectrometry (GC-MS). The risk Quotient (RQ) method was adopted for ecological risk assessments by using fish, daphnia, and algae as indicators. The concentration of OCPs ranged from 10.11 to 125.65 μg/kg and 10.96–45.17 μg/kg in Lake Tana and Hayqe, respectively. There was a statistically significant difference in the mean concentration of OCPs across the sampling sites in Lake Tana. Deltamethrin and lindane exhibit comparatively lower concentrations among the OCPs, whereas endrin, DDT, and their metabolites were the predominant pesticides in the study area, exceeding WHO and USEPA residue limits, except for endosulfan. Risk Quotient values ranged from 0.006 to 865.4 in Lake Tana and 0.005 to 729.9 in Lake Hayqe, indicating potential low to high ecological risks for aquatic organisms. High ecological risks are particularly evident in fish, daphnia, and algae species exposed to α and β-Endosulfan, DDT, and their metabolites, while specifically in daphnia, endrin poses high ecological risks. The ANOVA test revealed there were statistically significant differences (p-value <0.05) among sampling sites in Lake Tana and the mean values between Lake Tana and Lake Hayqe, underscoring the importance of addressing pesticide-related ecological concerns in the region.

A facile in-situ ultrasonic-assisted synthesis of terephthalic acid-layered double hydroxide/bacterial cellulose: Application for eco-friendly analysis of multi-residue pesticides in vineyard soils

A novel nanostructure biosorbent comprised of bacterial cellulose (BC) and a Cu-Cr layered double hydroxide (LDH) intercalated with terephthalic acid (TPA) was prepared using the in-situ coprecipitation method. The synthesized TPA/CuCr-LDH@BC sorbent was used in quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction of multiclass pesticides (nine insecticides, five acaricides, one herbicide, and one fungicide) followed by gas chromatography-mass spectrometry. The extraction factors such as type and volume of eluent, sorbent dosage, adsorption and desorption times, sample pH, and salt were optimized. The sorbent was analyzed with field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and adsorption/desorption isotherms to check its chemical structure, crystallinity, and porosity. Matrix effect (15.3–19.6 %), linearity (20–2000 µg/L, r2 > 0.9982), limits of quantification (6–12 µg/L), and enrichment factor (42–65) were calculated. The efficiency and accuracy of the developed method were assessed with the analysis of five vineyard soil samples and the resulting recoveries were in the range of 60–130 % (RSD%=3.5–12.9). The green aspects of the procedure were evaluated by the Complex-GAPI, the AGREE, and the Analytical Eco-Scale tools. This study describes the first-time synthesis of TPA/CuCr-LDH@BC composite and its application as sorbent material for the microextraction of multi-residue pesticides in agricultural soils.

Comprehensive analysis of contaminants in Brazilian infant formulas: Application of QuEChERS coupled with UHPLC-QqQ-MS/MS and suspect screening-unknown analysis by UHPLC-Q-Orbitrap-MS

Infant formulas (IF) can contain harmful chemical substances, such as pesticides and mycotoxins, resulting from the contamination of raw materials and inputs used in the production chain, which can cause adverse effects to infants. Therefore, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) methodology prior ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPL-QqQ-MS/MS) analysis was applied for the determination of 23 contaminants, in 30 samples of Brazilian IF. The method was validated in terms of limit of detection (0.2 to 0.4 μg/kg), limits of quantification (1 and 10 μg/kg), and recovery (64 % to 122 %); precision values, in terms of relative standard deviation (RSD), were ≤ 20 %. Fenitrothion, chlorpyrifos, and bifenthrin were the pesticides detected in the samples, but the values did not exceed the limit set by the European Union (EU), and ANVISA, and they were detected under their limits of quantification. Additionally, suspect screening and unknown analysis were conducted to tentatively identify 32 substances, including some compounds not covered in this study, such as pesticides, hormones, and veterinary drugs. Carbofuran was identified, confirmed and quantified in 10 % of the samples.

Quantitative MALDI-MS and Imaging of Fungicide Pyrimethanil in Strawberries with 2-Nitrophloroglucinol as an Effective Matrix.

This work explores the use of 2-nitrophloroglucinol (2-NPG) as a matrix for quantitative analysis of the fungicide Pyrimethanil (PYM) in strawberries using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and imaging. 2-NPG was selected for PYM analysis for optimum sensitivity and precision compared to common matrices α-cyano-4-hydroxylcinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB). PYM-sprayed strawberries were frozen 0, 1, 3, and 4 days after treatment and sectioned for MALDI imaging. The remaining part of each strawberry was processed using quick easy cheap effective rugged and safe (QuEChERS) extraction and analyzed by MALDI-MS and ultraperformance liquid chromatography multireaction-monitoring (UPLC-MRM). MALDI-MS showed comparable performance to UPLC-MRM in calibration, LOD/LOQ, matrix effect, and recovery, with the benefit of fast analysis. The MALDI imaging results demonstrated that PYM progressively penetrated the interior of the strawberry over time and the PYM concentration on tissue measured by MALDI imaging correlated linearly with MALDI-MS and UPLC-MRM measurements and accounts for 79% MALDI-MS and 85% UPLC-MRM values on average. Additionally, quartz crystal microbalance (QCM) was introduced as a new approach to determine strawberry tissue mass per area for MALDI imaging absolute quantitation with sensitive, direct, and localized measurements. This work demonstrates the first example of absolute quantitative MALDI imaging of pesticides in a heterogeneous plant tissue. The novel use of the 2-NPG matrix in quantitative MALDI-MS and imaging could be applied to other analytes, and the new QCM tissue mass per area method is potentially useful for quantitative MALDI imaging of heterogeneous tissues in general.

Validation of a modified QuEChERS method for the quantification of residues of currently used pesticides in Cuban agricultural soils, using gas chromatography tandem mass spectrometry.

We present an analytical method to detect and quantify residues of currently used pesticides (CUPs), which include 31 active ingredients (ai) and seven transformation products (TPs) in tropical and agricultural soils of Cuba. Ten isotopically labeled analogous compounds served as internal standards (IL-IS). The novelty of this research is the inclusion of different tropical soils type scarcely studied for CUPs and TPs, based on the QuEChERS (quick, easy, cheap, effective, rugged and safe) method, followed by chromatography tandem mass spectrometry. All figures of merit proved to be satisfactory according to SANTE guidelines 2020 and 2021. Matrix effects (ME) calculated by the external standard method were significant (|ME| > 20% for almost all compounds; grand mean ± standard deviation (STD) 104 ± 108%) in all soils. The internal standard method compensated ME to non-significant levels (8 ± 50%), even for analytes with a non-structure identical IL-IS (STD, 13 ± 57%). Repeatability (relative standard deviation, RSDr) and reproducibility (RSDR) for skeletic regosol (SR) were 7.5 ± 2.8% and 11.7 ± 4.7%, respectively. Absolute (quantified for 11 analytes with structure identical IL-IS) and relative recovery from SR was 92 ± 13% (mean ± STD) and 90 ± 12%, respectively. Limits of quantification for SR ranged from 0.1 to 10 ng/g, except metalaxyl and oxyfluorfen (25 ng/g each). Linearity of matrix-matched (MM) calibration curves (5 to 100 ng/g) had an R2 of ≥ 0.99 for all soils and almost all analytes. The method was successfully applied to 30 real soil samples.

Development and validation of an analytical method based on QuEChERS followed by UHPLC–ToF-MS for the determination of tropane alkaloids in buckwheat (Fagopyrum esculentum L.) and buckwheat products

A method was developed for the determination of tropane alkaloids (TAs), including atropine, scopolamine, anisodamine and homatropine in buckwheat and related products. This work presents an optimised methodology based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction procedure followed by ultra-high performance liquid chromatography combined with time-of-flight mass spectrometry for the determination of TAs (atropine, scopolamine, anisodamine and homatropine) in buckwheat samples. The analytical methodology was successfully validated, demonstrating good linearity, low limit of quantification, repeatability (RSDr < 15%), inter-day precision (RSDR < 19%) and recovery (74–113%). Finally, 13 commercial samples of buckwheat were analysed and the results demonstrated that they were in compliance with the current European regulations regarding TAs.

Optimization of the QuEChERS Extraction of Mycotoxins in Maize Using Response Surface Methodology (RSM)

AbstractSeveral methods have been developed for the analysis and detection of mycotoxins in food; however, most do not make use of critical statistics and mathematical tools for precise optimization. This study developed, optimized, and validated a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction procedure for the extraction of multiple mycotoxins in maize and subsequent validation using liquid chromatography tandem mass spectrometry (LC–MS/MS). Central composite design (CCD) was used to optimize extraction conditions. Data analysis of full factorial screening experiments revealed that MeCN (%), FA (%), and extraction time significantly affected the mycotoxins recovery. Assessment of the statistical significance of the generated model using analysis of variance (ANOVA), coefficient tables, and surface plots showed the relative interactions of factors and the adequacy of the model. Thus, P values from the lack of fit (LOF) test ranged from 0.137– 0.467 and a composite desirability function of 0.91 was obtained. Using the optimum extraction conditions of 0.1% (v/v) FA in 80.2% MeCN for 74 min, 10 mycotoxins were effectively extracted with satisfactory recoveries (85–114%), coefficients of regression (R2 &gt; 0.98), coefficients of variation (CVs &lt; 15%), limit of quantifications (LOQs) (0.33–60.45 µg/kg), and other associated method validation parameters. The method validation was carried out according to Commission Implementing Regulation 2021/808 and Commission Regulation (EC) No 401/2006 of 23 February 2006. Application of this method to 20 maize samples collected from markets in Botswana showed detectable mycotoxins in 13 samples, with 2 exceeding the European Union (EU) maximum aflatoxin B1 (AFB1) limit, suggesting potential exposure to high levels of toxic mycotoxins in Botswana.

Development of Green and Facile Sample Preparation Method for Determination of Seven Neonicotinoids in Fresh Vegetables, and Dissipation and Risk Assessment of Imidacloprid and Dinotefuran.

A facile procedure for extracting and determining seven neonicotinoids was developed. Water was the only extraction solvent without phase separation and cleanup steps. The method was validated according to European Union standards, and the values obtained were compared with the criteria. The accuracy values were between 99.8% (thiamethoxam) and 106.8% (clothianidin) at the spiking levels of 0.01, 0.1, and 1 mg/kg in the tested matrices. The precision as pooled RSD values was ≤6.1% (intra-day) and ≤6.9% (inter-day). The limit of quantification was set and tested at 0.01 mg/kg. The matrix effect was evaluated, and all matrices had a suppressive effect. The matrix of the cucumber was the most effective, with -20.9% for dinotefuran and an average of -9.8% for all compounds, while the tomato matrix had the slightest effect. Real marketed samples were analyzed using the developed and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) methods; the results were not significantly different. A supervised field trial was conducted in the open field to study the dissipation patterns of imidacloprid and dinotefuran in tomatoes. The dissipation of both compounds followed first-order kinetics. The half-life (T½) values were 3.4 and 2.5 days, with dissipation rates k of 0.2013 and 0.2781 days, respectively. Following the EU-MRL database, the calculated pre-harvest interval (PHI) values were 7 and 14 days for imidacloprid and dinotefuran, respectively, and 3 days for both compounds following Codex Alimentarius regulations. The risk of imidacloprid and dinotefuran residues was estimated from chronic and acute perspectives. The risk factors of dinotefuran were lower than those of imidacloprid. Nonetheless, the highest expected residues of both compounds were below the tolerance limits.

Organochlorine, organophosphorus, and carbamate pesticide residues in an Ethiopian Rift Valley Lake Hawassa: occurrences and possible ecological risks.

Currently, pesticide production and use are on the rise globally. This trend is certain to continue in the coming decades with residues posing risks to the environment and human health even at low levels. Although various aspects of pesticides and their possible implications have widely been studied, such studies have mostly been carried out in developed countries leaving the rest of the world with little scientific information. We present here the results of a study on the occurrences, concentrations, and ecological risks of 30 pesticide residues (PRs) in water and sediment samples from a tropical freshwater Lake Hawassa in the Ethiopian Rift Valley. A total of 54 composite samples of water and sediment were collected from three sampling sites on three occasions. The samples were prepared by quick, easy, cheap, effective, rugged, and safe (QuEChERS) technique, and analyzed using GC-MS at Bless Agri Food Laboratory Service located in Addis Ababa, Ethiopia. The study applied the risk quotient (RQ) method to scrutinize the risks posed to aquatic biota by the detected PRs. The results showed occurrences of 18 and 20 PRs in the water and sediment samples, respectively. The majority, 78 and 75% of the detected PRs in water and sediment samples, respectively represent the organochlorine chemical class. Concentrations of heptachlor epoxide were significantly (p ≤ 0.001) higher than those of the remaining pesticides in both matrices. Of the pesticides detected, 77% were present in water and 83% in sediment samples and pose a serious risk (RQ ≥ 1) to the Lake Hawassa biota. This calls for further research to investigate the risks to human health posed by the PRs. The findings of this study can contribute to the development of global protocols, as they support the concerns raised about the ecological and public health impacts of PRs on a global level.

Determination of Pesticide Residues in Vine Leaves Using the QuEChERS Method and Liquid Chromatography-Tandem Mass Spectrometry.

Commercial viticulture necessitates regular pesticide applications to manage diseases and pests, raising significant concerns regarding pesticide residues among stakeholders. Due to health risks associated with these residues in Turkish vine leaves, the European Commission has increased the frequency of official control from 20% to 50%. Thus, the aim of this study was to determine multi-class pesticide residues in brined vine leaves from Turkey. A total of 766 samples of vine leaves were collected between May 2022 and June 2023. More than 500 residues were analyzed using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, followed by liquid chromatography-tandem mass spectrometry. In-house validation data demonstrated that the analytical method exhibits fit-for-purpose performance in terms of linearity, accuracy, precision, and measurement uncertainty. Out of 766 samples analyzed, 180 samples (23.5%) contained one (131, 17.1%) or multiple (49, 6.4%) pesticides. Both the frequencies of occurrence and the rate of maximum residue level (MRL) exceedance increased in 2023 compared to 2022, with the MRL exceedance rate rising from 9.5% to 25.2%. Forty-three different residues were found in quantifiable concentrations and eight of them were non-approved. Among the residues, the non-systemic pyrethroid insecticides, lambda-cyhalothrin (8.0%) and cypermethrin (7.2%), were the two most frequently detected, with concentrations ranging from 0.010 to 0.248 mg kg-1 and from 0.011 to 0.533 mg kg-1, respectively. Turkey is a major exporter of vine leaves and these results provide crucial information regarding pesticide occurrence and quality assessment of vine leaves. The significant increase in both pesticide occurrence and MRL exceedance rates between 2022 and 2023 underscores the urgency for regulatory bodies to reassess current pesticide usage and monitoring practices. The findings emphasize the importance of implementing more stringent rules and improving enforcement methods in order to reduce the spread of unapproved pesticides and ensure adherence to global food safety standards.

Residue behavior and consumer risk assessment of spirotetramat and chlorpyrifos on cabbage heads and cropped soil.

A field experiment following good agricultural practices was laid out to study the dissipation of spirotetramat (90 g a.i. ha-1 and 180 g a.i. ha-1) and chlorpyrifos (400 g a.i. ha-1 and 800 g a.i. ha-1) on cabbage heads and soil. Samples were processed using quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for residue estimation of spirotetramat and chlorpyrifos, which were further detected using HPLC-PDA and GC-FPD respectively. The residues of spirotetramat on cabbage heads reached below detection limit (BDL) (< 0.05 mg kg-1) on 7th and 10th day and for chlorpyrifos, BDL (< 0.01 mg kg-1) was achieved on 10th and 15th day for X and 2X dose, respectively. On 20th day after second spray, residues in soil were found to be BDL for both the pesticides. Half-life of spirotetramat and chlorpyrifos was found to be 3 and 2 days, respectively while a safe pre-harvest interval (PHI) of 9 days for spirotetramat and 10 days for chlorpyrifos is suggested on cabbage. The dietary risk assessment studies for various age groups of Indian population, ascertained safety of treated cabbage heads for consumption, as current study revealed that hazard quotient (HQ) < 1 and theoretical maximum dietary intake (TMDI) < maximum permissible intake (MPI) for both the pesticides at respective PHI.

Dissipation kinetics, residue level, and risk assessment of chlorantraniliprole in Rosa roxburghii and its residue removal using household decontamination technique

Rosa roxburghii (R. roxburghii) is edible and medicinal fruit rich in vitamin C. Residues and potentially ecological risks of chlorantraniliprole (CAP) in the R. roxburghii orchard have aroused concern considering its extensive use for controlling oriental fruit moth, aphid, and whitefly of R. roxburghii. In this study, an effective UPLC–MS/MS method was developed for quantitation of CAP in R. roxburghii and soil using modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) dispersive solid-phase extraction with average recoveries of 73.89–96.63% and a relative standard deviation of &lt;15%. Dissipation dynamics and terminal residue trials under the field conditions in 2021 and 2022 showed that half-lives of CAP in R. roxburghii (2.64–2.70 days) were shorter than those in soil (3.58–3.80 days), and its terminal residues in R. roxburghii and soil were 0.034–0.818 mg kg-1 and 0.003–0.015 mg kg-1, respectively. Long-term dietary and soil ecological risk assessments indicated that the risk quotient was significantly less than 100%, meaning that the use of CAP on R. roxburghii at the recommended dosage was safe to consumers and soil ecology system, and that maximum residue limits (MRLs) and safe pre-harvest intervals of CAP in R. roxburghii were recommended as 0.7 mg kg-1 and 14 days, respectively. Removal experiments of CAP residues from R. roxburghii using simple household processing approaches exhibit that 2% baking soda water had the highest removal efficiency (56.04–60.33%). This study provides the basic data for establishing MRL, the safe and rational use of CAP in R. roxburghii production as well as the household decontamination prior to consumption of R. roxburghii fruits.

Comprehensive Characterization of Organic Light-Emitting Materials in Breast Milk by Target and Suspect Screening.

Organic light-emitting materials (OLEMs) are emerging contaminants in the environment and have been detected in various environment samples. However, limited information is available regarding their contamination within the human body. Here, we developed a novel QuEChERS (quick, easy, cheap, effective, rugged, and safe) method coupled with triple quadrupole/high-resolution mass spectrometry to determine OLEMs in breast milk samples, employing both target and suspect screening strategies. Our analysis uncovered the presence of seven out of the 39 targeted OLEMs in breast milk samples, comprising five liquid crystal monomers and two OLEMs commonly used in organic light-emitting diode displays. The cumulative concentrations of the seven OLEMs in each breast milk sample ranged from ND to 1.67 × 103 ng/g lipid weight, with a mean and median concentration of 78.76 and 0.71 ng/g lipid weight, respectively, which were higher compared to that of typical organic pollutants such as polychlorinated biphenyls and polybrominated diphenyl ethers. We calculated the estimated daily intake (EDI) rates of OLEMs for infants aged 0-12 months, and the mean EDI rates during lactation were estimated to range from 30.37 to 54.89 ng/kg bw/day. Employing a suspect screening approach, we additionally identified 66 potential OLEMs, and two of them, cholesteryl hydrogen phthalate and cholesteryl benzoate, were further confirmed using pure reference standards. These two substances belong to cholesteric liquid crystal materials and raise concerns about potential endocrine-disrupting effects, as indicated by in silico predictive models. Overall, our present study established a robust method for the identification of OLEMs in breast milk samples, shedding light on their presence in the human body. These findings indicate human exposure to OLEMs that should be further investigated, including their health risks.

Phytochemical profiling and bioactivity study of Adenia panduriformis in Zambia using UHPLC-MS/MS-MZmine3, GNPS, and METLIN Gen2

Diseases, especially degenerative illnesses, can be treated and avoided altogether, and good health can be enhanced by including health-promoting foods in the diet without side effects. Adenia panduriformis (Passifloraceae) is a wild vegetable consumed as part of the everyday diet in some communities in Zambia. The plant is also used in traditional medicine to effectively treat and manage many diseases, including degenerative diseases. Because of significant health benefits and medicinal attributes, this vegetable has very high merit to be investigated for its phytochemicals and bioactivities. Therefore, this study screened phytochemicals using qualitative chemical tests and Liquid chromatography-tandem mass spectrometry (LCMS/MS), identified metabolites using molecular networking tools and evaluated the total polyphenolic content and antioxidant activity of the methanolic leaf extract of the vegetable. Solvent extraction by maceration recovered metabolites for screening by qualitative chemical tests, extraction by QuEChERS (quick, easy, cheap, effective, rugged, and safe) was used to recover metabolites for screening by LCMS/MS, and tentative phytochemical constituents were identified using MZmine3, GNPS (global natural products social molecular networking) and METLIN. Total phenolic content (TPC) determination used the Folin-Ciocalteu (FC) method at 765 nm. Total flavonoid content (TFC) was evaluated using the aluminium chloride colorimetric assay at 510 nm. Antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay at 517 nm. Phytochemical screening by qualitative chemical tests revealed the presence of many classes of phytocompounds, such as alkaloids, polyphenols, terpenoids, and saponins. TPC was determined to be 122.30 ± 2.00 mg GAE/g, and TFC was 60.17 ± 0.25 mg QE/g. Screening by LCMS/MS revealed the presence of many metabolites, of which 23 phytocompounds were identified using MZmine3, 42 by GNPS, and 21 by METLIN. The crude extract exhibited high DPPH free radical quenching activity with a relatively low IC50 value of 53.48 µg/mL compared to the reference standard ascorbic acid IC50 of 74.47 µg/mL. The significantly lower IC50 value for the wild vegetable than that of ascorbic acid indicates a considerably high efficiency of the metabolites in the vegetable as antioxidants. The presence of many metabolites with health-promoting properties and high antioxidant activity of the leaf extract of A. panduriformis may be the science behind its remarkable health benefits and power to treat and manage a variety of diseases, including degenerative illnesses. This study presents results that indicate the potential of A. panduriformis as a rich source of metabolites with brilliant health-promoting properties and high antioxidant activity, which may open exciting opportunities for further development in the fields of pharmacology and drug development.

An Optimized and Validated QuEChERS-Based Method for the Determination of PCBs in Edible Aquatic Species

AbstractIn the present research, a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was optimized and validated for the determination of 14 selected PCB congeners in mussel (Mytilus galloprovincialis) and fish samples (Sparus aurata). The optimization included the selection of different QuEChERS procedures, extraction solvent, sample weight, and suitable sorbents for the clean-up step to achieve high sensitivity and minimal matrix interferences simultaneously. The identification and quantification of the selected PCBs were carried out using GC–MS. The method was validated providing in all cases excellent linearity (r2 above 0.99). Recoveries were estimated at three different fortification levels (10, 50, and 100 ng g−1) and ranged from 72.5 to 109.5% and 72.1 to 88.4% for mussel and fish samples, respectively. In addition, for both matrices, the LOQs ranged from 1 to 2.5 ng g−1. The matrix effect was in all cases &lt; 29%, while the expanded uncertainty U%, which was estimated at all the fortification levels, was found below 53% in all cases. Eventually, the optimized and validated method was applied to mussel and fish samples acquired from aquacultures in NW Greece, revealing the absence of the selected congeners in all cases.

Determination of erythromycin, clarithromycin and N-desmethyl-erythromycin A residues in pork, beef and lamb based on a simple and fast extraction procedure followed by ultrahigh-performance liquid chromatography with triple quadrupole/linear ion trap mass spectrometry

A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method was developed for the simultaneous determination of erythromycin (ERY), clarithromycin (CLA) and N-desmethyl-erythromycin A (N-D-ERY) in pork, beef and lamb via ultrahigh-performance liquid chromatography with triple quadrupole/linear ion trap mass spectrometry (UHPLC-QTRAP-MS/MS). The sample preprocessing and detection conditions were optimized, and the obtained parameters of all target compounds met the EU and FDA requirements. In the sample preprocessing procedure, acetonitrile-water (80:20, v/v) was used as an extractant, and a Cleanert MAS-Q cartridge was utilized and achieved good extraction recovery. The matrix-matched calibration curves showed good linearities, with determination coefficients of 0.9983–0.9999. The recoveries ranged from 88.96% to 101.76% with relative standard deviations (RSDs) ≤5.95%, and the intraday and interday RSDs ranged from 2.64% to 6.65% and 3.08–6.38%, respectively. The limits of detection and quantification for the pork, beef and lamb samples were 0.4 μg/kg and 2.0 μg/kg, respectively. The detection limits and detection capabilities were in the range of 2.15–215.16 μg/kg and 2.26–230.32 μg/kg, respectively. This method was successfully applied to the analysis of the pork, beef and lamb samples, demonstrating its applicability and suitability for the routine analysis of ERY, CLA and N-D-ERY residues in meat samples.

Occurrence and distribution of trisiloxane ethoxylates in citrus orchard soils in China: Analytical challenges

Trisiloxane ethoxylates (TSEOn) are widely used as agricultural surfactants due to their significant synergism with the active ingredients of pesticides, generally, including three typical end groups which are hydroxyl (TSEOn-H), methoxy (TSEOn-CH3), and acetoxy (TSEOn-COCH3), respectively. However, the potential ecotoxicological and endocrine-disrupting risks of TSEOn congeners have recently attracted ever-growing concern. Above all, there is limited research on the concentration levels of TSEOn in agroecosystems. This study, simultaneous analysis of 39 TSEOn oligomers in citrus orchard soils in China was implemented by the modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method detection limits (MDLs) and the method quantification limits (MQLs) for TSEOn were 0.003–0.07 μg/kg and 0.01–0.20 μg/kg, respectively. The recoveries for TSEOn oligomers in soils ranged from 81 % ∼ 106 % with related standard deviations (RSDs) < 7 %. This newly developed UPLC-MS/MS method with high sensitivity and stability allows us to successfully trace the occurrence of TSEOn congeners in the citrus orchard soils from 3 provinces and 1 municipality in China. The detected concentrations of TSEOn-H oligomers in the sampled soils ranged from 0.02 to 0.288 μg/kg (dry weight). The congener profiles of TSEOn-H were dominated by TSEOn-H (n = 6– 8) in the soils. Additionally, the total concentrations of TSEOn-H congeners (ΣTSEOn-H) in the soils were in the range of 0.03 to 1.49 μg/kg. A comparison of ΣTSEOn-H distribution among the different citrus orchard soils indicated a higher level of ΣTSEOn-H in the soil samples collected from Zhejiang Province. Notably, TSEOn-CH3 or TSEOn-COCH3 oligomers were not detected in the tested soils. To the best of our knowledge, this is the first report on the occurrence and distribution of TSEOn congeners in agricultural soils.

Dissipation and residues of 18% imidacloprid + buprofezin SC in citrus and soil

ABSTRACT Eighteen per cent imidacloprid + buprofezin suspension concentrate (SC) has been registered for the control of scale insect on citrus trees, but the dissipation of this pesticide mixture on citrus is still a research blank area. In order to fill the gaps and ensure the safe application of mixture formulation, field trials were conducted in Guangdong, Guangxi and Hunan Provinces of China for 2 consecutive years to evaluate the final residue and dissipation dynamic of imidacloprid and buprofezin in citrus and soil. Both pesticides were extracted by the modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method, while imidacloprid was determined by high-performance liquid chromatography (HPLC) and buprofezin was determined by gas chromatography (GC). The established method achieved a good linearity relationship (r = 0.9999) and high sensitivity, the LODs (limit of detection) of imidacloprid and buprofezin were 0.002–0.013 mg/kg, which can fully meet the need for pesticide residue detection. Average recoveries (AR) of imidacloprid and buprofezin in citrus and soil were 77.64–105.95% and 85.89–102.28%, with relative standard deviations (RSD) of 3.06–7.91% and 3.29–7.25%, respectively. Results of field trials showed that the half-lives of imidacloprid in citrus and soil were 1.90–3.97 and 2.52–16.98 days, and that of buprofezin were 1.69–9.14 and 1.21–8.56 days. On the 21st day after the last application, final residues of imidacloprid and buprofezin in all samples were below their maximum residue limits (MRL) stipulated by China, indicating that it is safe to apply 18% imidacloprid + buprofezin SC on citrus trees. In conclusion, 18% imidacloprid and buprofezin SC was recommended to be spared twice at the intervals of 7 days with dosages of 180 or 270 mg/L, and the citrus fruit can be harvested safely 21 days after the last application. These results help ensure the safe application of imidacloprid and buprofezin in citrus orchards.

Simultaneous determination of sulfonylurea herbicides in tomatoes using the QuEChERS method coupled with HPLC

The simultaneous determination of trace pesticides in complex matrices containing high concentrations of natural pigments remains challenging. In this study, quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation together with high-performance liquid chromatography with ultraviolet detection (HPLC–UV) was applied for the multi-residue analysis of seven sulfonylurea herbicides (SUHs) in tomatoes. SUH residue was extracted using the QuEChERS procedure, followed by solid-phase extraction (SPE) and dispersive SPE (d-SPE). To reduce the amount of carotenoids in tomato extracts, several d-SPE clean-up procedures were compared, and octadecylsilane (C18) provided the best color removal rate (%) of tomato extracts and recoveries (%) for all the tested SUHs. The validation results indicate good linearity (R2 > 0.9970), accuracy, and precision. Recoveries of 70–120% and relative standard deviations < 20% were achieved for all analytes at three spiked concentrations. The limits of detection and quantification for the 7 SUHs were 0.003 mg kg−1 and 0.008–0.009 mg kg−1, respectively. The developed method was subsequently used to quantify multi-residue SUHs during real sample analysis. None of the tested samples had SUH residue levels higher than the maximum residue limits established by the Korean Ministry of Food and Drug Safety. The results suggest that QuEChERS sample preparation employing a combination of C18 is a high-throughput and rapid clean-up procedure for the multi-residue analysis of SUHs in tomatoes.