Presence Of Pesticide Residues Research Articles

Organophosphate, carbamate and synthetic pyrethroid pesticide residues in muscle tissues of fish from Loktak Lake, a Ramsar Site in Manipur, India

The muscle tissues of Channa punctatus and Anabas testudineus collected from the Loktak Lake (a Ramsar site) and its three major feeder rivers in Manipur, Northeastern India, were analyzed using high-performance liquid chromatography for the presence of residues of organophosphorus, carbamate, and synthetic pyrethroid pesticides. Pesticide residues of all the three types were detected in the fish tissues. Pesticide residues in Channa punctatus ranged from 0.002 – 0.043 µg g-1, and from 0.008 –0.027 µg g-1in Anabas testudineus from Loktak lake in pre-monsoon and post-monsoon seasons. Pesticide residues were detected only in Anabas testudineus (0.002 – 0.078 µg g-1) in Nambul river, while these were detected only in Channa puctatus (0.001 – 0.032 µg g-1) in Moirang river. In Nambol river, pesticide concentrations ranged from 0.002 – 0.026 µg g-1 in Channa punctatus, and from 0.004 – 0.005 µg g-1 in Anabas testudineus. Among the five pesticides detected, concentrations of dichlorvos residues detected in the present study (0.027 and 0.032 µg g-1 wet weight) exceeded the Codex Alimentarius maximum residue limit (MRL) of 0.01 mg kg-1 for animal tissues. The rest of the compounds were within the MRL. None of the pesticide residues was detected in the two fish species collected from the control or reference site. The present study indicates that pesticide contamination is emerging as a threat to the water quality and aquatic biodiversity of Loktak Lake, which calls for more detailed studies on the extent and magnitude of these threats.

Occurrence, distribution, and dietary risk assessment of pesticides in apples at the provincial scale

Apples are widely favored by consumers, but the presence of pesticide residues can pose risks to their quality and safety. This study investigated the residual levels of pesticides in commercial apples from 11 cities in Shanxi Province, using analytical methods to detect 102 pesticides. A total of 34 pesticides were detected, with the highest detection rate observed for carbendazim (78.95%), tebuconazole (57.14%), and acetamiprid (53.38%). Pesticide concentrations ranged from below 2 μg/kg to 522.96 μg/kg, with all levels remaining within the maximum residue limits (MRLs) in China. The retention factors, which characterize the distribution pattern, exhibited a significantly positive correlation with the base-10 logarithms of the octanol-water partition coefficient (pKow). All detected pesticides showed acceptable acute dietary risks, with values below 21.33% for different consumer groups, as assessed by deterministic and probabilistic models. This study enhances the understanding of residual pesticide levels and dietary risks of pesticides in apples at the provincial scale and promotes the rational application of pesticides.

Pesticide residues in European sediments: A significant concern for the aquatic systems?

The presence of pesticide residues in waterbed sediments poses a significant concern for aquatic ecosystems' health. This study examined pesticide contamination in sediments of 38 water bodies, embedded in agricultural-dominated regions, across eight European countries. Three indicators were targeted: occurrence, type, and concentrations of multiple pesticide residues in sediments. 196 pesticide residues (including degradation products) were tested in the sediment samples. The analytical results showed that only one sample was ‘pesticide-free’, three samples contained a single pesticide residue, and the remaining 34 samples contained mixtures of residues. Overall, 99 different residues were found in the sediments, with a maximum of 48 in a single sample. Twenty-seven out of the 99 detected residues were not approved for agricultural use at the time of sampling. The numbers of detected residues and pesticide levels varied among countries. AMPA, glyphosate and DDTs were the most common residues in sediment samples with frequencies of 76, 61, and 52%, respectively. The sediments from the Czech Republic had the highest pesticide concentrations, with total pesticide concentrations ranging between 600 and 1200 μg kg−1. The lowest total pesticide concentrations were found in Slovenia, Switzerland, Croatia, and Denmark, ranging between 80 and 120 μg kg−1. Sediments presented a mix of non-persistent and persistent compounds. Twelve of the detected pesticides are very persistent/stable in sediments, raising concerns about the long-term impacts of pesticides. Our study on the distribution of pesticide residues in European sediments provides valuable insights into the extent of pesticide contamination and possible risks of pesticides to water bodies' health. It also underlines the need for monitoring, research, and policy efforts to mitigate the impacts of pesticides, and to evaluate potential risks of re-use of dredged sediments.

Comprehensive assessment of clean-up strategies for optimizing an analytical multi-method to determine pesticides and mycotoxins in Brazilian medicinal herbs using QuEChERS-LC-TQ-MS/MS.

The use of medicinal herbs has increased significantly. However, the presence of pesticide residues and mycotoxins in medicinal herbs has generated constant discussion and concern among regulatory agencies. Developing and validating an analytical method for determining pesticides and mycotoxins in medicinal plants is challenging due to the naturally occurring substances in these plants. The purpose of this work was to develop and to optimize a sensitive, accurate, precise, effective QuEChERS method for simultaneous determination of over 160 pesticide and mycotoxin residues in complex medicinal plant matrices using LC-TQ-MS/MS. A comprehensive comparison of clean-up procedures and other parameters was conducted to achieve this goal. The validation procedure was performed according to SANTE 11312/2021. More polar analytes, such as acephate, methamidophos and omethoate, presented a higher negative matrix effect in both Melissa officinalis L. and Malva sylvestris L. However, other molecules, such as spirodiclofen, showed a 24% signal enhancement in M. officinalis and a 46% signal suppression in M. sylvestris, indicating that a representative matrix-matched calibration would lead to inaccurate quantification of the analyte. Accuracy and precision were satisfactory according to SANTE 11312/2021 for 157 pesticide residues and mycotoxins in M. officinalis and for 152 molecules in M. sylvestris. LOQs at 10 µg kg-1 were achieved for 117 pesticides in M. officinalis and 99 pesticides in M. sylvestris. Among the mycotoxins, all four aflatoxins (B1, B2, G1 and G2) presented LOQs of 5 µg kg-1, and ochratoxin A had an LOQ of 10 µg kg-1 in M. officinalis. The same LOQ values were shown for these mycotoxins in M. sylvestris, except for aflatoxin B2 and ochratoxin A, which had LOQs of 20 µg kg-1. Moreover, in Southern Brazil, there has been no previous study on mycotoxin and pesticide contamination in medicinal herbs. Therefore, the application of this method was assessed through the analysis of forty-two real samples. Imidacloprid was found in M. officinalis, and methyl pirimiphos was found in M. sylvestris. The proposed method not only serves as a helpful tool for routine monitoring but also offers a basis for further research on risk assessment and control in food safety.

MONITORING OF PESTICIDE RESIDUES IN GRAPEVINE LEAVES UNDER VARIANT FUNGAL DISEASE MANAGEMENT

Food contamination is the result of over-reliance on fungicides in crop production. The presence of pesticide residues in agricultural commodities needs to be strategically solved by applying gentle agrotechnical procedures. The research aimed to evaluate the effect of the treatment of grapevine with fungicides on the content and mobility of 4 active substances in the leaves of the variety Hibernal. The experiment included a control variant treated with fungicides and an untreated variant. We focused on monitoring the active substances of fungicides used in the first half of the vegetation: azoxystrobin, cyflufenamid, difenoconazole, myclobutanil, and another 25 active substances, in terms of multi-residue analysis methodologies. Grape leaves for analysis were collected on two dates: in the phenological phase of berry development BBCH 73 and 14 days after grape harvest – BBCH 91. Samples were prepared according to STN EN 15662. For qualitative analyzes of residues, we used the QuEChERS method in combination with liquid (LC-MS/MS) and gas (GC-MS/MS) chromatography with tandem mass spectrometry. In the untreated variant, the contents of residues from both leaves collection were in undetectable values. In the leaf samples of the treated variant collected in BBCH 73, we established higher values of residues than the MRL determines, namely for azoxystrobin 0.083 mg/kg (MRL – 0.01 mg/kg). Azoxystrobin is the active substance of the Quadris max fungicide, and we applied this preparation 41 days before the first collection of leaves. In the analyzes of leaf sampling from the treated variant after grape harvest in BBCH 91, we found a decrease in the content of all monitored residues below detectable values. We consider the gradual degradation of residues in biological materials to be a very favorable result from the point of view of their impact on consumer health and the environment. Through visual observations of the vegetation, we found out that even the untreated variant had a perfect state of health. Hibernal is a variety suitable for biological production systems, and we assume that even in vintages with high pressure of fungal diseases, it is possible to maintain the health of the grapevine with ecological products. Using the appropriate grape variety combined with the right agrotechnical interventions makes it possible to use safer ecological practices to produce healthy food, maintaining sustainability and a healthy natural environment. The research will continue in the early Table grape varieties, where the vegetation period is shorter, and space for breaking down the residues is more difficult.

Dissipation behavior and risk assessment of imidacloprid and its metabolites in apple from field to products

Pesticides play vital roles in controlling pests and boosting crop yields. Imidacloprid is widely used all over the world and may form in agricultural products. The presence of pesticide residues in apples raises serious health concerns. Understanding the residual fate of imidacloprid is critical for food safety and human health. In this study, the dissipation behavior, metabolism, household processing and risk assessment of imidacloprid and its metabolites in apple were investigated from filed to products. Field experiment results suggested that the half-lives of imidacloprid at 5 times the recommended dosage was 1.5 times that of the standard dosage. And the final residues of imidacloprid were less than the established maximum residue limits (MRLs). Clarification and simmering had little effect on the reduction the residues of imidacloprid and its metabolites. The calculated processing factors were lower than 1 for imidacloprid and its metabolites, implying that the residual ratios of imidacloprid and its metabolites in each steps of the food processing were reduced. The risk quotients were <1 for all Chinese people, indicating that acceptable risks associated with dietary exposure to imidacloprid in apple. However, the higher risks were observed in young people than adults, and females faced higher risks than males. Given high residue levels in pomace, imidacloprid and its metabolites should be further studied in commercial byproducts.

Risk assessment of multiple pesticide residues in Agrocybe aegerita: Based on a 3-year monitoring survey

The presence of pesticide residues in Agrocybe aegerita has raised an extensive concern. In this paper, based on a 3-year monitoring survey, the dietary exposure risks through A. aegerita consumption for different population subgroups were assessed using both deterministic and semi-probabilistic approaches under the best-case and the worst-case scenarios. Among the 52 targeted pesticides, 28 different compounds were identified in the concentration range of 0.005–3.610 mg/kg, and 87.4 % of samples contained one or more pesticide residues. The most frequently detected pesticide was chlormequat, followed by chlorfenapyr and cyhalothrin. The overall risk assessment results indicated extremely low chronic, acute, and cumulative dietary exposure risks for consumers. Using the ranking matrix, intake risks of pesticides were ranked, revealing endsoluran, chlorpyrifos, and methamidophos to be in the high-risk group. Finally, considering various factors such as the toxicity and risk assessment outcomes of each positive pesticide, use suggestions were proposed for A. aegerita cultivation.

Bioenzyme–nanoenzyme–chromogen all-in-one test strip for convenient and sensitive detection of malathion in water environment

The presence of pesticide residues in aquatic environments poses a significant threat to both aquatic ecosystems and human health. The presence of these residues can result in significant harm to aquatic ecosystems and can negatively impact the health of aquatic organisms. Consequently, this issue requires urgent attention and effective measures to mitigate its impact. However, developing sensitive and rapid detection methods remains a challenge. In this study, an all-in-one test strip, which integrated bioenzymes, nanoenzymes, and a chromogen, was developed in combination with an enzyme labeling instrument for a highly sensitive and convenient sensing of malathion residues. The oxidase activity of heme chloride (Hemin) in the strip can catalyze the oxidation of H2O2 and 3,3′,5,5′-tetramethylbenzidine (TMB) to produce a blue-colored oxide. Simultaneously, the alkaline phosphatase (ALP) present in the strip can break down l-ascorbic acid-2-phosphate to produce ascorbic acid (AA). This AA then acts to reduce the oxidized form of TMB, turning it into a colorless substance and leading to the disappearance of its fluorescent signal. In the presence of a pesticide, the activity of ALP is inhibited and formation of AA is blocked, thereby preventing the reduction of oxidized TMB and producing a colored signal. According to this principle, the integrated test strip detected the target pesticide with high performance as per the optical density value determined via an enzyme marker. The detection limit of the test strip was 0.209 ng/mL with good sensitivity. The method was used for detecting malathion in actual river water samples, and the recoveries were in the range of 93.53 %–96.87 %. The newly devised technique effectively identified malathion in samples of natural water. This research has introduced a novel approach for the precise and convenient surveillance of pesticide remnants. Additionally, these discoveries could inspire the advancement of proficient multi-enzyme detection systems.

Effect of aqueous ozone treatment on the reduction of chlorpyrifos and physicochemical and microbial qualities of cucumber (Cucumis sativusL.): Process modeling and optimization

AbstractA study was conducted at different combinations of ozone concentration (50%–100%) and time (10–30 min) to study the effect of aqueous ozone treatment on chlorpyrifos degradation in cucumber. A process was developed and compared using ANN‐GA and RSM techniques. The optimum conditions obtained using RSM were ozone concentration of 95% and treatment time of 10 min. While the optimum conditions achieved by ANN‐GA were ozone concentration of 81% and treatment time of 14 min. However, chlorpyrifos degradation is more at the condition optimized by ANN compared to the condition optimized by RSM. At the optimum condition, the cucumber showed superior physicochemical and microbial qualities, including pesticide degradation (91.08%), color change (3.58), firmness (11.75 N), moisture content (97.49%), water activity (0.93), pH (6.18), titratable acidity (0.06%), total soluble solids (2.1 °Brix), total plate count (1.5 × 105 CFU/g), and yeast/mold count (3 × 105 CFU/g), respectively.Practical applicationsIncreased awareness of the health benefits associated with the consumption of fruits and vegetables has led to a rise in their consumption. These items are primarily consumed in their raw or fresh state and often feature in salads. However, the presence of pesticide residues on the surface of raw fruits and vegetables can pose significant health risks to consumers. Ozone treatment can be used for effectively removing pesticide residue in the fresh‐cut fruits and vegetables industry. Also, ozone treatment can reduce the microbial count on the surface of fruits and vegetables which enhances the shelf life of fruits and vegetables. Furthermore, it can prevent the natural ripening process of commodities, thereby increasing the consumer's acceptance. Ozone is considered a safe and eco‐friendly alternative to chemical disinfectants and preservatives. It leaves no chemical residue on the produce and breaks down into oxygen, leaving no harmful byproducts, thereby ensuring safe consumption of the commodity.

Pesticide residues in drinking water treatment plants and human health risk assessment: a case study from Northern Iran.

These days, the presence of pesticide residues in drinking water sources is a serious concern. In drinking water treatment plants (DWTPs), various methods have been proposed to remove pesticide residues. This study was designed with the objectives of monitoring the occurrence and seasonal variations of pesticides in the output of drinking water treatment plants in two Northern provinces of Iran, Gilan and Golestan, and identifying their human health risks. Seventeen pesticide residues from different chemical structures were determined by using a gas chromatograph-mass spectrometer (GC-MS). The results showed that only Alachlor, Diazinon, Fenitrothion, Malathion, and Chlorpyrifos were detected. The pesticide concentrations ranged from ND to 405.3ng/L and were higher in the first half-year period. The total non-carcinogenic human health risks was in safe range for infants, children, and adults (HI < 1). The carcinogenic human health risks of Alachlor for infants, children, and adults were in the range of 4.3 × 10-7 to 1.3 × 10-6, 2.0 × 10-7 to 9.6 × 10-7, and 1.1 × 10-7 to 5.5 × 10-7, respectively. These values do not pose health risks for adults and children, but may present a possible cancer risk for infants in two DWTPs of Golestan. In conclusion, considering the possibility of exposure to these pesticides through other routes, simultaneously, it is suggested to carry out a study that examines the level of risk by considering all exposure routes. We also propose stricter regulations for the sale and use of pesticides in Iran.

Viruses, microsporidia and glyphosate residues in Africanized honey bees Apis mellifera, under field conditions

Bees are affected by several factors, including pathogens and pesticides, which may cause mortality and consequent population decline. Considering the ecological and economic importance of these pollinators, this study evaluated the occurrence of the microsporidia Nosema apis and Nosema ceranae, the viruses ABVP, DWV, BQCV, KBV, IAPV and CBPV and residues of the pesticides atrazine, chlorantraniliprole, deltamethrin, fipronil and glyphosate in workers from field colonies of Africanized honey bee Apis mellifera across one year. The presence of pesticide residues was also evaluated in honey and pollen samples. All tested viruses were found in the workers, with BQCV showing the highest copy number. BQCV levels were correlated with relative humidity. Nosema ceranae was the only microsporidian with higher intensities of infection during summer and autumn; seasons with high availability of food resources, which can act as dispersers of this pathogen. Small amounts of glyphosate and its metabolite were detected in the bees tested. These data show that honey bees are contaminated with pathogens and pesticides in the field and present correlative data for these threats.

PESTICIDE RESIDUE SCREENING IN CITRUS FRUITS BASED ON GAS CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY AND HEALTH RISK ASSESSMENT

Lately, there is maximum concern in most states, all over the world, regarding the levels of pesticide residues in food products, considering their chemical properties with direct implications on human health. Many studies have shown that the adverse effects of cumulative exposure to multiple pesticide residues are far more severe than any single exposure. Statistically, the number of food alerts generated by the presence of pesticide residues in fruits on the market, between 2017 and 2021, as well as the situation related to the number of imports and intra-EU trade that took place during the same period was highlighted. This study aims to analyze pesticide residue levels in citrus fruits (i.e., lemons, grapefruit, and orange) imported from non-EU and EU countries, comparative with maximum residue limits (MRLs) provided by Regulation 2005/396/EC, to assess if intake levels pose a long-term risk to human health. The citrus samples collected from ten markets (retail and storage areas) in Romania, were prepared according to the procedure provided by EN 15662:2008 standard. The concentration of pesticide residues from citrus samples was determined by Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS). The results obtained by GC-MS/MS showed that from 52 citrus samples, 41 samples contained pesticide residues with values between 0.005 and 2.700 mg/kg, and several samples contained forbidden active substances (e.g., spirodiclofen and o-phenylphenol). The pesticide detection rate of the samples was 78.84%. The most frequently detected pesticides according to obtained results were imazalil, thiabendazole, pyrimethanil, pyraclostrobin, fludioxonil, as well as spirodiclofen and o-phenylphenol. The samples with the most detected active substances are from imports outside of the European Union. In addition, in several samples, simultaneously occurred four or even five mixed pesticide residues, hazardous to human health. This study shows that the presence of pesticide residues is constant in citrus fruits due to phytosanitary treatments carried out on crops in the development phase as well as on fruits in the storage phase treatments (e.g. insecticides, fungicides, etc.).

Evaluation of Organophosphates Residue in Stored Cereals from Some Selected Markets in Jalingo, Nigeria

Cereal grains such rice, sorghum, maize and millet among others are the staple foods in large parts of the world, supplying most of the energy and bulk in diets. Pesticide residue analysis in cereals from the various sampling locations for this dissertation revealed the following organophosphate pesticide residue were present in cereals analyzed Dichlorvos, Diazinon, Phorate sulfon, Malathion, Phorate, Chloropyrifos, Methyl Parathion, Profenofos, Ethion, Dimethoate, Phorate Sulfoxide, Phosalone, Edifenfos, Fenitrothion and Chlorofenvinfos. The presence of pesticide residues is detected in the samples of cereals (Rice, Maize, Millet and sorghum) analyzed. This could be as a result of high utilization of various pesticides during plant, cultivation and storage thus leading to the bioaccumulation of this substance in the individual cereals. It indicates high levels of non-carcinogenic risk associated with the life time consumption of cereals produce and sold within this region. Based on findings from this study’s, I hereby make the following recommendations. Regulatory agencies in Nigeria should step up efforts to ensure compliance with the ban on these chemicals. Farmers and other pesticide users also need to be educated on the dangers of using banned products and on the over application of these pesticides. Furthermore, farmers should be educated on the properly usage of these chemical product, during plant, harvest and storage. Also, manufacturers of these chemicals should produce less toxic pesticide using organic materials in other to prevent the health risk associated with chemical pesticide and their residues in food crops and the environment.

Monitoring of pesticide residue in pistachio nut samples by LC/MS-MS

The presence of pesticide residues in agricultural products is one of the most important challenges to food safety. The use of pesticides in the cultivation of pistachios can lead to residues above the Maximum Residue Levels (MRLs). The current research focused on quantifying 112 pesticide residues utilizing Ultra High-Performance Liquid Chromatography tandem Mass Spectrometry (UHPLC-MS/MS). A modified quick, easy, cheap, effective, rugged, and safe“ (QuEChERS) method was used for sample preparation. The linearity of the method was investigated with the procedural calibration curve over six concentration levels ranging from 0.015 to 0.5 mg/kg. The method's repeatability at two levels, 0.1 and 0.3 mg/kg, was established, ranging from 0.5 % to 20 %. The limit of detection (LOD) and quantification (LOQ) of pesticides were around 0.003 mg/kg and 0.01 mg/kg, respectively. Acetamiprid and Thiacloprid were found at the permitted level in 7 and 3 out of the 20 samples.

Evaluation of the nutritional value and presence of minerals and pesticides residues in agro-industrial by-products to replace conventional ingredients of small ruminant diets

Fruit and vegetable production across the Mediterranean generates large volumes of by-products that can potentially lessen the livestock feeds deficit in some regions due to climate change effects and other socio-economic factors. However, the utilisation of agro-industrial by-products to their full potential is hindered by several factors such as variability in composition, limited development of preserving technologies and the presence of undesirable substances that may represent a risk for the animal or the final consumer. This work was conducted to study the nutritive value of a range of different alternative by-products from the Spanish agro-industry, assessing the potential to replace conventional ingredients often used in diets for small ruminants and the risk associated with the presence of pesticide residues and minerals. A total of 15 agro-industrial by-products commonly available in different regions of Spain were tested: three different types of apple pomace from three different varieties of apples (Perico, Regona, and Solarina), lemon pulp, avocado seed, broccoli, watermelon silage, olive cake, avocado cake, and six types of silages made with straw and a combination of different by-products (80/20 on fresh matter basis) from the intensive greenhouse horticulture: cucumber, tomato, pepper-cucumber mix (Pep-Cuc silage), aubergine-tomato mix (Aub-Tom silage), tomato-pepper-watermelon mix (Tom-Pep-Wat silage), and watermelon-melon-tomato mix (Wat-Mel-Tom silage). The study involved chemical characterization, including minerals and pesticides residues, and in vitro assessment of the ability to partially replace (10%, 20%, 30%, 50% and 100%) conventional ingredients in a diet for adult sheep (oat hay, barley and sunflower meal), depending on their chemical composition. The inclusion of by-products up to 30% replacement had not effect or improved some of the fermentation parameters and cucumber silage and apple pomace could successfully replace 100% of oat hay and barley, respectively, with only a significant reduction (P < 0.006) of rumen ammonia concentration. The mineral content was highly variable among the by-products with high values of Al in watermelon silage, Cu in olive cake and avocado by-products and Ni and Cr in olive cake. The pesticide residues assessment included 45 different types of compounds commonly used in crop production and three by-products had levels of pesticides residues above the legal limit: watermelon silage had traces of Chlorpyrifos (0.06 mg/kg DM), lemon pulp had Imazalil (0.09 mg/kg DM), and cucumber silage and Wat-Mel-Tom silages had Thiabendazole (0.04 mg/kg DM). Although all by-products showed potential to replace conventional ingredients from a nutritional perspective, the presence of high levels of some minerals and pesticides residues in some by-products requires regular analyses throughout the year or across batches before feeding them to animals.

Citrus Canopy SPAD Prediction under Bordeaux Solution Coverage Based on Texture- and Spectral-Information Fusion

Rapid and nondestructive prediction of chlorophyll content and response to the growth of various crops using remote sensing technology is a prominent topic in agricultural remote sensing research. Bordeaux mixture has been extensively employed for managing citrus diseases, such as black star and ulcer disease. However, the presence of pesticide residues in Bordeaux mixture can significantly modify the spectral response of the citrus canopy, thereby exerting a substantial influence on the accurate prediction of agronomic indices in fruit trees. In this study, we used unmanned aerial vehicle (UAV) multispectral imaging technology to obtain remote sensing imagery of Bordeaux-covered citrus canopies during the months of July, September, and November. We integrated spectral and texture information to construct a high-dimensional feature dataset and performed data downscaling and feature optimization. Furthermore, we established four machine learning models, namely, partial least squares regression (PLS), ridge regression (RR), ridge, random forest (RF), and support vector regression (SVR). Our objectives were to identify the most effective prediction model for estimating the SPAD (soil plant analysis development) value of Bordeaux-covered citrus canopies, assess the variation in prediction accuracy between fused features and individual features, and investigate the impact of Bordeaux solution on the spectral reflectance of the citrus canopy. The results showed that (1) the impact of Bordeaux mixture on citrus canopy reflectance bands ranked from the highest to the lowest as follows: near-infrared band at 840 nm, red-edge band at 730 nm, blue band at 450 nm, green band at 560 nm, and red band at 650 nm. (2) Fused feature models had better prediction ability than single-feature modeling, with an average R2 value of 0.641 for the four model test sets, improving by 0.117 and 0.039, respectively, compared with single-TF (texture feature) and -VI (vegetation index) modeling, and the test-set root-mean-square error (RMSE) was 2.594 on average, which was 0.533 and 0.264 lower than single-TF and -VI modeling, respectively. (3) Multiperiod data fusion effectively enhanced the correlation between features and SPAD values and consequently improved model prediction accuracy. Compared with accuracy based on individual months, R improved by 0.013 and 0.011, while RMSE decreased by 0.112 and 0.305. (4) The SVR model demonstrated the best performance in predicting citrus canopy SPAD under Bordeaux solution coverage, with R2 values of 0.629 and 0.658, and RMSE values of 2.722 and 2.752 for the training and test sets, respectively.

Development of a sensitive fluorescent immunoassay based on fluorescent nanoparticles labeling for the quantitation of fipronil in edible flowers

Edible flowers have long been used for tea, functional foods, and spices, however, during planting, these natural products are vulnerable to pests and fungal diseases. In recent years, the presence of pesticide residues in edible flowers has attracted extensive attention and of the pesticides found in these products, fipronil residue has been widely reported. Therefore, it is imperative to develop a simple, sensitive, and reliable method for detecting fipronil in edible flowers. In this study, a novel labeled antibody was synthesized by using fluorescent nanoparticles as a secondary antibody, and a fluorescence immunoassay method was established with the conjugated conjugate. The limits of detection and half maximal inhibitory concentration of this method were 0.21 μg/L and 8.61 μg/L, respectively. Furthermore, the developed method was 3.5 times more sensitive than the enzyme-linked immunosorbent assay. After verification, the established method was successfully applied to determine fipronil levels in edible flower samples, and then validated with a gas chromatography-tandem mass spectrometry method. To our knowledge, this is the first report on the successful application of fluorescent nanoparticles in the detection of fipronil in edible flowers.

Influence of Phytosanitary Practices in Tunisian Vineyards on the Presence of Pesticide Residues in Winegrapes

Influence of Phytosanitary Practices in Tunisian Vineyards on the Presence of Pesticide Residues in Winegrapes

Determination and risk assessment of 31 pesticide residues in apples from China's major production regions

The presence of pesticide residues in apple fruit raises serious health concerns. In multi-residue pesticide analysis, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method has gradually replaced less efficient traditional extraction methods. This study developed a modified QuEChERS method coupled with ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to simultaneously detect the residue of multiple pesticides in apple fruit. The method exhibited high linearity (R2 ≥ 0.99), and excellent recoveries (74.4–118.1 %) for 31 pesticides with relative standard deviations below 20 %. The limit of detection and limit of quantification were 0.1–4.0 μg/kg and 2.0–10.0 μg/kg, respectively. By using the established method, 20 pesticides were detected in 152 'Fuji' apple samples collected from the orchards of 17 cities in two major apple production regions of China, with an overall detection rate of 58.6 %. The residue levels were below the maximum levels set by GB 2763–2019. Moreover, both the chronic dietary intake risk (%ADI) and the acute dietary intake risk (%ARfD) for all the detected pesticides were lower than 100 %, indicating that the dietary intake risks are acceptable and would not pose potential health risks.

Chromatographic Method for Monitoring of Pesticide Residues and Risk Assessment for Herbal Decoctions Used in Traditional Korean Medicine Clinics.

The presence of pesticide residues in herbs and the herbal products derived from them raises serious health concerns. This study was conducted to investigate the residual pesticide concentrations and assess potential human health risks from herbal medicines used in traditional Korean medicine clinics. A total of 40 samples of herbal decoctions were collected from 10 external herbal dispensaries. The pesticide residues were analyzed by the multiresidue method for 320 different pesticides using liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography tandem mass spectrometry (GC-MS/MS). As a result of the monitoring, carbendazim was detected at 0.01 and 0.03 μg/g in eight samples and no pesticide was detected in the other herbal decoctions. Carbendazim was set for each individual item as less than 0.05 μg/g in Paeoniae radix, less than 0.05 μg/g in Cassiae semen, less than 2.0 μg/g in Lycii fructus, and less than 10 μg/g in Schisandrae fructus (dried). Therefore, the results of this study suggested that the detected pesticide residues in herbal decoctions could not be considered as posing a serious health risk.