Determination Of Pesticide Residues Research Articles

Effectiveness of Water Hyacinth Biochar as a Potential Adsorbent in Solid-Phase Extraction Together with Liquid Chromatography-Mass Spectrometry for Determination of Pesticide Residues in Lager Beer

Effectiveness of Water Hyacinth Biochar as a Potential Adsorbent in Solid-Phase Extraction Together with Liquid Chromatography-Mass Spectrometry for Determination of Pesticide Residues in Lager Beer

Quantitative determination of residue amounts of pesticide active ingredients used in grapes by LC-MS/MS and GC-MS/MS devices and evaluation of these pesticides in terms of public health.

The aim of this study was to quantitatively determine pesticide residues in grapes, one of the most produced and consumed fruits in Turkey and in the world. A total of 226 active ingredients were analyzed in 21 samples collected from Southeastern and Eastern Anatolia regions using QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction method and multiple residue analysis technique and LC-MS/MS and GC-MS/MS devices. In 11 out of 21 samples (52.4%), no active ingredient was detected, while at least one active ingredient was detected in 10 samples (47.6%). Thirteen different active substances (Ametoctradin, Azoxystrobin, Boscalid, Diphenoconazole, Dimethomorph, Fenhexamid, Fluopyram, Flutriafol, Metalaxyl- Metalaxyl-M, Metrafenone, Tebuconazole, Trifloxystrobin) were detected in the samples. The top 3 most detected active substances were Boscalid-Azoxystrobin and Fluopyram, respectively. The active ingredients were found between 0.015 and 0.499 mg kğ-1 values.

Determination of pesticide residues and heavy metals in Adhatoda Vasaka Linn.

Heavy metals and pesticide residue analysis plays an important role in the quality control of medicinal plants like Vasaka (Adhatoda vasica). Hence a study was conducted to determine heavy metals and pesticide residues in this medicinal herb, which is a highly useful commodity in the health system. The reliable, rapid and nontoxic sample preparation method like QuEChERS and analytical methods like GC-MS were proposed for the simultaneous determination of pesticide residues and Heavy metal detection was carried out by ICP-MS. In this study, the presence of organophosphorus and organochlorine pesticides like alachlor, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, etc was checked but not detected. Heavy metals like Arsenic (As), Cadmium (Cd), Mercury (Hg) and Lead (Pb) are traced in samples about 2.3005 ppb, 0.799 ppb, 2.290 ppb and 10.204 ppb respectively in the present study.

Optimization of QuEChERS method for determination of pesticide residues in vegetables and health risk assessment.

The present study focused on the optimization of the QuEChERS extraction method for the determination of 61 pesticide residues and associated health risk assessment in 144 samples of commonly consumed vegetables, viz., eggplant, cabbage, green chilli, okra, and tomato. The samples were collected between January and April 2022 from three different districts within Gujarat, India. The QuEChERS method was optimized and utilized for the extraction of samples. The samples were analyzed by UHPLC-q-TOF/MS and GC-MS/MS. The modified QuEChERS method was successfully validated, and the obtained results were satisfactory as per the 2021 SANTE guidelines. The residue analysis of the vegetable samples showed that about 4% of total samples contained single pesticide residues. Pesticide residues below the quantitation limit (BQL) were observed in eggplant, cabbage, and okra samples. In total, 15.62% (n = 5) samples of green chilli showed the presence of pesticides such as azoxystrobin, bifenthrin, cypermethrin, fenpropathrin, and propargite whereas 3% (n = 1) tomato samples contained cyfluthrin. In total, 97.22% of the samples had residues that were below the European Union Maximum Residue Limit (EU MRL). Two samples of green chilli had pesticide residues above EU MRL. The Hazard Index (HI) and Hazard Quotient (HQ) were used to assess the health risks associated with green chilli and tomato consumption. The HI and HQ values for adolescents and adults were found to be less than 1. The modified QuEChERS method was found to be easy and effective and can be implemented for routine sample analysis. The study revealed the presence of pesticide residues in tomato and green chilli samples. Further, the outcome provided information pertaining to current pesticide status, concluding that consumption of these commodities is unlikely to pose any health risk, though long-term monitoring studies focusing on dietary health risk assessment must be initiated.

Organophosphate pesticide residue impact on water quality and changes in macroinvertebrate community in an Afrotropical stream flowing through farmlands.

River Chanchaga has experienced significant agricultural practices around its catchment, which involved the indiscriminate use of pesticides. However, residents of the study area are not well aware of the negative impact of pesticides on water quality and macroinvertebrates. In this study, the first report on the influence of organophosphate pesticide contamination on the abundance of the macroinvertebrate community was provided. Sampling for the determination of organophosphate pesticide residues was carried out during the peak of the two seasons, while macroinvertebrates and physicochemical variables were observed for 6 months. We examined 11 organophosphate pesticide residues using gas chromatography coupled with mass spectrometry, 12 water quality variables, and 625 macroinvertebrate individuals. The concentration of recorded organophosphate pesticide residues ranged from 0.01 to 0.52 μg/L. From the Canonical Correspondence Analysis plot, malathion, chlorine, and paraffin show a positive correlation with Unima sp., Hydrocanthus sp., Chironomus sp., and Potadoma sp. At station 3, depth shows a positive correlation with Biomphalaria sp. and Zyxomma sp., indicating poor water quality as most of these macroinvertebrates are indicators of water pollution. Diuron and carbofuran show a negative correlation with Lestes sp. and Pseudocloeon sp., and these are pollution-sensitive macroinvertebrates. The total mean concentration of organophosphate pesticide residues was above international drinking water standards set by the World Health Organization except for paraffin, chlorpyrifos, and diuron. In conclusion, the observations recorded from this research are useful in managing pesticide applications around the river catchment.

Rapid determination of thiram in lake water using Au/Fe3O4 nanoparticles decorated MOF-867 as efficient surface-enhanced Raman scattering substrate

Rapid determination of pesticide residues in water is of vital importance for human health. However, rapid, reliable, and highly sensitive detection of pesticide residues in water environments remains a challenging issue. In this paper, we prepare Fe3O4/MOF-867 composites using the hot solvent method, and Au+ is reduced to Au NPs by the reducing agent and attached to the film of Fe3O4/MOF-867 composites by the addition of APTES as a linker to synthesize the Au/Fe3O4/MOF-867 SERS substrates. Then, we change the Fe3O4 content and the concentration of the reducing agent to obtain the optimal substrate. The substrate has a detection capability of up to 10−9 M for probe molecule R6G and the RSD is less than 5%, which demonstrates that the substrate has excellent SERS effect and reproducibility. In addition, the Au/Fe3O4/MOF-867 SERS substrates have been applied for the determination of thiram in lake water samples, with its limit of detection (LOD) up to 3.8 × 10−10 M. The Au/Fe3O4/MOF-867 SERS substrates can quickly and efficiently collect target analytes by magnetic enrichment, have high SERS performance, and have great potential for the rapid and sensitive detection of pesticide residues and other pollutants in the environment.

On-site preparation of sandwich plasmonic coupled SERS tape toward pesticide residue determination on food surface.

Asandwich plasmonic coupled surface enhanced Raman spectroscopy (SERS) tape is proposedprepared by peeling the chemical printed silver nanocorals (AgNCs) from Cu sheet with adhesive tape, which can sample targets from food surface and sandwich them between substrates and Cu sheet for SERS detection. The solid-to-solid transformation method for fabricating SERS tapes can effectively avoid the weakening of tape stickiness during the preparation process. The sandwich plasmonic coupled structure of AgNC substrate, targets, and Cu sheet display excellent SERS activity (EF = 1.62 × 107) for sensitive determination of analytes. In addition, due to the high heat conductivity of Cu sheet, the thermal effect of laser irradiation during SERS detection cannot damage the AgNC tapes, which ensures the reproducibility of subsequent quantification. The sandwich plasmonic coupled SERS tape is demonstrated to quantify malachite green (MG) and methyl parathion (MP) with good linear coefficients (> 0.98) by two typical calibration plots under different concentration ranges. The limit of detection (LOD) of the method is 0.17 ng/cm2 and 0.48 μg/cm2 (S/N = 3) for MG and MP. This method can realize the quantitative determination of MP and MG on the surface of fruits and fish scale with recoveries of 93-113%. The satisfactory detection results demonstrate the proposed sandwich plasmonic coupled AgNC tape can be successfully applied toSERS-based point-of-care testing (POCT) for pesticide residue determination, which will provide a new path for designing and constructing SERS tapes.

Ag-modified CuO cavity arrays as a SERS-electrochemical dual signal platform for thiram detection

Rapid and sensitive determination of pesticide residues in fruits and vegetables is critical for human health and ecosystems. This paper used an Ag-modified CuO sphere-cavity array (CuO@Ag) electrode as a thiram SERS/electrochemical dual readout detection platform. Numerous Raman “hotspots” generated by uniformly distributed silver nanoparticles, charge transfer at the CuO@Ag interface, and the formation of Ag-thiram complexes contribute to the significant enhancement of this SERS substrate, which results in excellent SERS performance with an enhancement factor up to 1.42 × 106. When using SERS as the readout technique, the linear range of the substrate for thiram detection was 0.05–20 nM with a detection limit (LOD) of up to 0.0067 nM. Meanwhile, a correlation between the value of change in current density and thiram concentration was established due to the formation of stable complexes of thiram with Cu2+ generated at specific potentials. The linear range of electrochemical detection was 0.05–20.0 μM, and the detection limit was 0.0167 μM. The newly devised dual-readout sensor offers notable sensitivity and stability. The two signal readout methods complement each other in terms of linear range and detection limit, making it a convenient tool for assessing thiram residue levels in agro-food. At the same time, the combination of commercially available portable equipment makes on-site monitoring possible.

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.

Determination of pesticide residue in soil samples by molecularly imprinted solid-phase extraction method

Abstract Porous molecularly imprinted polymer (MIP) microspheres were synthesized via iniferter-suspension polymerization method, employing lenacil (LA) as the template molecule and methacrylic acid (MAA) as the functional monomer. The host–guest complexes formed using LA and MAA were characterized by hydrogen nuclear magnetic resonance and ultraviolet–visible absorption spectroscopy. The obtained results showed that the interaction between LA and MAA mainly relied on hydrogen bonding. The surface morphologies and chemical structures of the MIPs were characterized by scanning electron microscopy. MIPs were spherical in shape with a relatively regular sphericity, rough surface structure, and numerous small holes, which significantly reduced the mass transfer resistance of the template molecules and exhibited excellent recognition performance for template molecules. In addition, soil samples were pretreated with solid-phase extraction columns molecularly imprinted with LA, and analyzed by high-performance liquid chromatography. The recoveries of LA, bromacil, and terbacil were up to 89.65%, 53.17%, and 44.63%, respectively. The developed method showed a minimum detection limit of 10–50 µg·mL−1. In view of the continuous increase of public requirements for pesticide residue detection, a versatile pretreatment method was developed that is green, rapid, simple, and can be miniaturized.

Simultaneous Determination of Trace Matrine and Oxymatrine Pesticide Residues in Tea by Magnetic Solid-Phase Extraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry

Simultaneous Determination of Trace Matrine and Oxymatrine Pesticide Residues in Tea by Magnetic Solid-Phase Extraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry

Chemometric Optimization of SPE for the Determination of Multiclass Pesticides in Portable Water Samples by UHPLC-MS/MS

This study aimed on the development of a SPE-UHPLC-MS/MS method for the simultaneous determination of pesticide residues in drinking water samples. A chemometric approach was applied to optimize the efficiency of the SPE pretreatment procedure. This study involved (i) the application of a Full Factorial Design for the screening of the significant factors, (ii) the application of a Central Composite Design for the determination of the optimal conditions and (iii) the evaluation and validation of the significance of the statistically proposed models. Oasis HLB cartridges were used for the extraction. The optimum sample volume was 300 mL and the elution solvent 3 mL of the mixture of methanol:ethylacetate 70:30 v/v. The method was validated according to the international guidelines. Recoveries were ranged from 63 to 116% and the detection limits were between 0.1 and 1.5 pg mL− 1. The validated method could be used in routine analysis for pesticides screening.

Method Development and Validation in Water Matrix Employing Tandem Mass Spectrometry: Quantitative Analysis of 76 Multiclass Pesticides in Groundwater Samples Collected from Delhi Ncr Region by Quechers Based Liquid-liquid Extraction Method

A miniaturized, QuEChERS based, liquid–liquid extraction method followed by tandem gas chromatography–mass spectrometry determination was developed and validated for 76 pesticide residues determination in water using European SANTE/11312/2021 guideline and monitored the 70 ground water samples collected from Delhi NCR, India region for the determination of pesticide residues. The accuracy, precision, specificity, linearity, recovery, repeatability, reproducibility, robustness, limit of detection and limit of quantification of the method were evaluated. Uncertainty measurement was calculated for each analyte. The samples were extracted with dichloromethane using liquid-liquid extraction process. Each Pesticide was optimized in terms of different MS parameters and chromatographic conditions by GC-MS/MS using Multiple Reaction Monitoring (MRM) mode. In linearity regression co-efficient (R2) value of each pesticide was determined in the range of 0.9856-0.9997. The percent average recoveries were found from 87.98—119.99 at 1, 5 and 10 LOQ spiking level. The method performance complied with the regulatory requirements, and thus, can be implemented. LOD and LOQ of the pesticides were found 10µg/L and 30µg/L respectively. Expanded Measurement of uncertainty of all pesticides was below ±50 percent of mean recovery value as per SANTE 11312/2021. Organophosphorous, fungicides, and pyrethroids were the group of pesticides most frequently found. In this study, 12 pesticides were found above the MRL (EEC Council Directive 1980/778/EEC). Additionally, dieldrin, which is now banned by law in India, was found in samples of ground water. The method provided a high throughput analysis of multi-class pesticides with satisfactory selectivity, sensitivity, accuracy, and precision.

A green-footprint approach for parallel multiclass analysis of contaminants in roasted coffee via LC-HRMS

The development and validation of a simple, comprehensive, and environment-friendly procedure to determine pesticide residues, naturally occurring and processing contaminants in roasted coffee is presented. A solid-liquid extraction of pesticides and mycotoxins with ethyl acetate and the concurrent partition of acrylamide to an aqueous phase follows a parallel analytical strategy that requires a single analytical portion to determine contaminants that are typically analyzed by dedicated single residue methods. The partition rules the lipids out of the aqueous extract before an “in-tube” dispersive solid phase microextraction (dSPME) for acrylamide retention. This is followed by the elution with buffer prior to injection. This extract is independently introduced into the system front end followed by the injection of the compounds from the organic phase, yet all spotted in the same run. A novel liquid chromatography high-resolution mass spectrometry (LC-HRMS) method setup enables the quantification of 186 compounds at 10 µg/kg, 226 at 5 µg/kg, and the acrylamide at 200 µg/kg for a total of 414 molecules, with acceptable recoveries (70–120%) and precision (RSD < 20%) making this strategy significantly faster and cost-effective than the dedicated single residue methods. Even though the presence of chlorpyrifos, acrylamide, and ochratoxin A was confirmed on samples of different origins, the findings were below the limit of quantification. During the storage of raw coffee, no proof of masking of OTA was found; however, condensation with glucose was evidenced during thermal processing experiments with sucrose by using stable isotope labeling (SIL). No detected conjugates were found in roasted nor in commercial sugar-added torrefacto samples, an industrial processing usually carried out above the decomposition temperature of the disaccharide.Graphical abstract

Determination, temporal variation and potential health risk assessment of pesticide residues in grapes from South and Southwest China

Pesticide residues in grapes from South and Southwest China were determined using the QuEChERS procedure and UHPLC-MS/MS and GC-MS/MS methods. The 4-year monitoring and survey showed 94.6% of the 1341 samples of grapes collected from eight main production areas contained one or multiple pesticide residues (above the respective LOQs). Overall, 40 pesticides were detected, including 24 fungicides, 12 insecticides, 2 acaricides and 2 plant growth modulators, of which one pesticide was unauthorised for use in treating grapes. Two or more pesticide residues were discovered in 87.4% of the samples (above the respective LOQs), and pesticide residues in 5.7% of the samples exceeded the MRLs, such as difenoconazole, cyhalothrin, propiconazole, etc. The main risk factors affecting the safety of grape before 2019 were difenoconazole, cyhalothrin and cyazofamid. After 2019, however, the frequency of occurrence of the above pesticides significantly declined, and the banned or restricted pesticides including omethoate were not found, which was credited to the stricter supervision and management policies by local governments. Despite the high detection rates and multi-residue occurrence of pesticides in grapes, about 84% of the samples were compliant with regulatory standards. Moreover, the accumulative chronic diet risk determined from ADI is very low. This study and timely monitoring can ensure that grape growers comply with GAP and minimise the occurrence of residues.

Polyaniline-coated kapok fibers for convenient in-syringe solid-phase microextraction and determination of organochlorine and pyrethroid pesticide residues in aqueous samples

Pesticides used in agriculture have low polarity and a tendency to accumulate in fatty tissues, posing potential risks to human health. Effective pre-treatment is crucial due to complex sample matrices and low concentrations of pesticide residues typically encountered in instrument analysis. In this study, polyaniline-coated kapok fiber (PANI-KF) was synthesized successfully using in-situ oxidative polymerization for use as sorbents in in-syringe SPME of pyrethroid pesticides (PYRs) and organochlorine pesticides (OCPs) from aqueous samples. Coating the natural KF with PANI maintained the hollow microtubular structure and fiber morphology while significantly enhancing the extraction efficiency. The extraction process was easily conducted by simply pulling and pushing the syringe plunger. The entire extraction process, utilizing 3 mg of PANI-KF, could be completed in approximately 3 min. Density functional theory results indicated that the adsorption mechanism of PANI-KF towards OCPs and PYRs mainly involved van der Waals interactions, π-π interactions, and weak hydrogen bonding interactions. With the coupling of gas chromatography-mass spectrometry, a quantification method was established that exhibited good linearities (R2 > 0.990), and relative recoveries (87.2–108.5 %). The limits of detection ranged from 0.4 to 2.0 ng mL−1 and the matrix effects were negligible (−12.3–16.4 %). The validated in-syringe SPME-GC-MS method was successfully applied to determine pesticide residues in fruit juices, oral liquids and herbal extract granules with satisfactory accuracy and precision. PANI-KF exhibits remarkable promise as a sorbent for the extraction and enrichment of pesticide residues in aqueous samples, thereby contributing to the advancement of pesticide residue determination methodologies.

Determination of dichlorvos pesticide residues in the groundwater of the environment surrounding Al‐Sin Lake using a high‐performance liquid chromatography

AbstractThe unreasonable use of agrochemicals and various human activities in the environment of Al‐Sin Lake basin may cause pollution to water, especially with widely used organophosphate pesticides, which have an effect on the human nervous system. This research sought to determine concentrations of dichlorvos of the synthetic organophosphate pesticide in the waters of the environment surrounding Al‐Sin Lake in the Syrian coastal area. A questionnaire form was dispensed to the local residents in the region, to determine the status of the studied area. Ground and surface water samples were collected from several locations surrounding the Lake. The first site is surrounded by greenhouses and a citrus orchard. The second is the Surit spring. The third site includes greenhouses. The fourth site represents surface water (Lake Surit). The study lasted for seven consecutive months from December until June 2020–2021, samples were taken once a month. Various parameters (pH, EC, TDS, and PO4−3) were measured. Dichlorvos was extracted from the samples using solvents (hexane‐acetone) to be ready for analysis using high‐performance liquid chromatography. The results showed the presence of dichlorvos residues in the studied water samples, with average concentrations ranging between 0.2 and 1.3 µg.L−1, which were higher than the recommended value for individual pesticide in water (0.1 µg.L−1) as recommended by the European Union. Observations of dichlorvos concentration indicated some increase at lower pH. Consequently, contamination of ground and surface waters with dichlorvos was observed in the studied sites, because of its frequent use and its high solubility in water. This unregulated use of dichlorvos can pose a matter of public health concern.

Residue estimation and dietary risk assessment of fenvalerate, novaluron, and profenofos in bell pepper grown under protected and open field conditions.

Residue studies were conducted in bell pepper crops (green and yellow bell pepper) to ensure the safe use of fenvalerate, profenofos, and novaluron (under open field and protected conditions) in randomized block design (RBD) following three applications at a 10-day interval over two consecutive years, 2021 and 2022. A robust analytical method was developed using quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS) for the determination of pesticide residues in bell pepper samples. The half-lives for fenvalerate were 2.47-2.87 and 2.50-3.03days on bell pepper under open field conditions, whereas the corresponding values for bell pepper under protected conditions were 3.84-4.58 and 4.17-4.71days, during 2021 and 2022, respectively. Profenofos displayed half-lives of 2.03-2.65 and 2.15-2.77days in open field conditions and 3.05-3.89 and 3.16-3.78days in protected conditions during 2021 and 2022, respectively. Similarly, novaluron had half-lives of 2.87-3.49 and 3.24-3.75days under protected conditions in 2021 and 2022, respectively. The maximum residue limits (MRLs) were calculated to be 0.6mg/kg for fenvalerate, while for profenofos it was 0.7mg/kg on bell pepper under open field conditions at double doses, at the proposed pre-harvest interval (PHI) of 3days. Likewise, for bell peppers grown under protected conditions, MRLs at the PHI of 3days were determined to be 0.8mg/kg for fenvalerate, 0.3mg/kg for novaluron, and 1.5mg/kg for profenofos. A dietary risk assessment study indicated that the percentage of acute hazard index (% aHI) was significantly lower than 100, and hazard quotient (HQ) values were below 1, signifying no acute or chronic risk to consumers. These findings underscore the safety of consuming bell peppers treated with fenvalerate, profenofos, and novaluron under the protected and open field conditions.

Development of a green analytical methodology based on a deep eutectic solvent for the determination of pesticide residues in industrial hemp

In this study, in accordance with the green analytical chemistry principles, the use of eco-friendly solvents has been proposed for the first time for the analysis of pesticide residues in industrial hemp (Cannabis sativa L.). With this aim, betaine-based natural deep eutectic solvents with lactic acid and propylene glycol were explored as extraction solvents in the solid–liquid extraction of fifteen pesticides from hemp samples. The mixture composed of betaine:propylene glycol at molar ratio 1:4 (n/n) was selected due to its better analytical performance. The separation, identification and quantification of pesticides were carried out by gas chromatography coupled to tandem mass spectrometry. The extraction protocol was optimised through the step-by-step strategy, evaluating NADES composition, water addition to the solvent, solid–liquid ratio, and re-extraction solvent. The analytical methodology was validated in terms of calibration (linear regression with R2 ≥0.9966), trueness and precision (average relative recovery of 63–77% with relative standard deviation ≤20%) and sensitivity (limits of quantification of 0.663–3.625 µg/kg). These results successfully demonstrated the convenience of the developed approach for the determination of pesticides in industrial hemp, which has industrial applications such as the production of food and supplements, cosmetics, and textiles, which should not compromise the health of consumers. In addition, the comparison with previously reported research in this field showed that not only the present method is more sensitive, but also more sustainable and economical.

Method Validation and Measurement Uncertainty Estimation for Determination of Multiclass Pesticide Residues in Tomato by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

Method validation is an essential technique for ensuring the reliability and accuracy of an analytical method. This study aimed to optimize and validate a fast, reliable, and accurate method for quantitatively determining pesticide residues of diverse chemical classes in the tomato matrix. Various method performance characteristics were tested and compared with predefined criteria. Twenty-six different pesticides of diverse chemical classes were selected based on their use in tomato cultivation and the availability of reference materials. The pesticide residues in tomato samples were extracted with the QuEChERS technique with some modifications, followed by injection into an LC-MS/MS system operating in an optimized method. The validated method demonstrated reasonable specificity, as there were no interferences from matrix components at the retention times of pesticides. The calibration curves for all pesticides exhibited excellent linearities, with correlation coefficients exceeding 0.99. No significant matrix effect was observed for all pesticides in tomatoes, as the values fell within the range of ±20%. All pesticides were quantified successfully at a concentration of 5 μg/kg except for carbaryl, with an average recovery of more than 70% and a relative standard deviation of less than 20%. Similarly, measurement uncertainties were also estimated based on the validation data, and the values were found below the default limit of 50%. Subsequently, the validated method was applied to analyze 52 locally collected tomato samples. Study findings revealed that only four of the studied pesticides were detected in these samples, and their concentrations were below the maximum residue limits (500 µg/kg each for carbendazim, imidacloprid, and metalaxyl) established for tomatoes by the Government of Nepal and the Codex Alimentarius Commission.