Commercial Pesticide Research Articles

Non-targeted analysis of co-formulants in antifungal pesticide formulations by gas chromatography-tandem high resolution mass spectrometry

In the present study, six commercial pesticide formulations with antifungal activity were characterized. Thus, two complementary injection methods based on gas chromatography were employed: direct injection (DI) and headspace (HS), both coupled to high resolution mass spectrometry (GC-Q-Orbitrap-MS). The combination of both injection modes allowed the tentatively identification of potential co-formulants. Available analytical standards were acquired for their confirmation, and 21 compounds were successfully confirmed. Finally, the concentration of these co-formulants was calculated, finding the highest value in one of the pesticide formulation, at 218.22 g L−1 for cyclohexanone.Results clearly show that this methodology is suitable for the reliable identification of co-formulants in pesticide formulations, offering high sensitivity, and highlighting that five co-formulants were detected by both injection techniques (DI and HS). Moreover, one of the main advantages of the proposed methods was the great capacity for the elucidation of compounds with similar molecular formula, bearing in mind that up to 8 co-formulants with the same molecular formula C10H14, were well differentiated by retention times between 8.46 (1-methyl-3-propylbenzene) and 10.98 min (1,2,3,4- tetramethylbenzene) in one of the pesticide formulation.Toxicity to human health and the environment has been evidenced for the co-formulants detected, finding compounds with relatively high toxicity, as naphthalene and cyclohexanone.

The surfactant co-formulant POEA in the glyphosate-based herbicide RangerPro but not glyphosate alone causes necrosis in Caco-2 and HepG2 human cell lines and ER stress in the ToxTracker assay.

The toxicity of co-formulants present in glyphosate-based herbicides (GBHs) has been widely discussed leading to the European Union banning the polyoxyethylene tallow amine (POEA). We identified the most commonly used POEA, known as POE-15 tallow amine (POE-15), in the widely used US GBH RangerPro. Cytotoxicity assays using human intestinal epithelial Caco-2 and hepatocyte HepG2 cell lines showed that RangerPro and POE-15 are far more cytotoxic than glyphosate alone. RangerPro and POE-15 but not glyphosate caused cell necrosis in both cell lines, and that glyphosate and RangerPro but not POE-15 caused oxidative stress in HepG2 cells. We further tested these pesticide ingredients in the ToxTracker assay, a system used to evaluate a compound's carcinogenic potential, to assess their capability for inducing DNA damage, oxidative stress and an unfolded protein response (endoplasmic reticulum, ER stress). RangerPro and POE-15 but not glyphosate gave rise to ER stress. We conclude that the toxicity resulting from RangerPro exposure is thus multifactorial involving ER stress caused by POE-15 along with oxidative stress caused by glyphosate. Our observations reinforce the need to test both co-formulants and active ingredients of commercial pesticides to inform the enactment of more appropriate regulation and thus better public and environmental protection.

Antibiotic Resistance of Pectobacterium Korean Strains Susceptible to the Bacteriophage phiPccP-1

Commercial products with antibiotics like streptomycin as active ingredients have been used to control soft rot disease caused by Pectobacterium species for a long time. In this study, antibiotic resistance of twentyseven Korean strains of Pectobacterium species including P. carotovorum, P. odoriferum, P. brasiliense, and P. parmenteri, which were previously shown to be susceptible to the bacteriophage phiPccP-1 was surveyed using a disk diffusion assay. While all strains were highly susceptible to ampicillin, kanamycin, chloramphenicol, tetracycline, and rifampicin, some strains showed weak susceptibility to 300 μg/ml of streptomycin. Furthermore, some of them are partially or completely resistant to commercial pesticides—Buramycin and streptomycin at the concentration of 250 μg/ml that is recommended by the manufacturer for streptomycin- based pesticides. These results indicate the presence of streptomycin-resistant Pectobacterium strains in South Korea, and the development of antibiotic alternatives to control soft rot is needed.

Plant volatile compound methyl benzoate is highly effective against Spodoptera frugiperda and safe to non-target organisms as an eco-friendly botanical-insecticide

Recent studies have indicated that the plant volatile methyl benzoate (MB) exhibits significant insecticidal bioactivity against several common insects. However, the potential environmental hazards of MB and its safety to non-target organisms is poorly understood. In the present study, these characteristics were investigated through laboratory experiments and field investigations. The results revealed that MB was highly toxic to the agricultural pest, fall armyworm Spodoptera frugiperda. Compared with the commercial pesticide lambda-cyhalothrin, the toxicities of MB against S. frugiperda larvae and adults were comparable and 3.41 times higher, respectively. Behavioral bioassays showed that the percentage repellency of MB to S. frugiperda larvae was 56.72 %, and MB induced 69.40 % oviposition deterrence rate in S. frugiperda female adults. Furthermore, in terms of median lethal concentration (LC50) and median lethal doses (LD50), MB exhibited non-toxic effects on non-target animals with 3-d LC50 of > 1 % to natural predators (Coccinella septempunctata and Harmonia axyridis), 3-d LD50 of 467.86 µg/bee to the bumblebee Bombus terrestris, 14-d LC50 of 971.09 mg/kg to the earthworm Eisenia fetida, and 4-d LC50 of 47.30 mg/L to the zebrafish Brachydanio rerio. The accumulation of MB in the soil and earthworms was found to be extremely limited. Our comparative study clearly demonstrated that MB is effective as a selective botanical pesticide against S. frugiperda and it is safe to use in the tested environment, with no toxic effects on non-target animals and natural predators.

Potential of kaffir lime (<em>Citrus hystrix</em>) leaf extract as biopesticide in improving pre and post-harvest quality of chili (<em>Capsicum annuum</em>)

Purpose: Chilli production in Malaysia is declining due to production problems such as pest and diseases which cause plants to become stunted, unhealthy, and damaged. To overcome this problem, most farmers prefer using chemical fertilizers and pesticides due to their fast reaction and effectiveness. In long term, application of these chemicals input may lead to an environmental damage and human health problems. To conserve our nature, the use of natural input in agriculture is highly recommended. Research Method: This study was conducted to identify the potential of plant extract, namely kaffir lime in increasing the plant productivity and reducing the severity of pests for chilli trees. The study was performed by spraying the chilli trees with 25, 50, and 75% (v/v) kaffir lime extracts. Controls consisted of plants without any treatment as negative control and plants applied with a commercial chemical pesticide as positive control. Findings: Results indicated that there were significant differences (p<0.05) between treatments with respect to all parameters including pre-harvest (plant height and pest severity) and postharvest (fresh weight and number of chilli pods) parameters except for the stem and crown diameter, soluble solid concentration, fruit firmness and colour measurement of chilli. The results found that chilli plants sprayed with 25% kaffir lime extract had the lowest pest infestation. Moreover, application of the 25% kaffir lime extract had produced the heaviest weight of chilli fruits and the highest number of chilli pods compared to other treatments including the positive control (chemical pesticide). Therefore, it was concluded that 25% kaffir lime extract produced healthier chilli plants, higher yield and better quality of chilli. Originality/ Value: Limited number of studies are available on eff ectiveness of kaffir lime-based insecticides. Therefore, this study was conducted as an effort towards understanding the versatility of kaffir lime leaves extraction as an alternative pesticide on chilli plants’ pre- and postharvest performance.

Comparison of the genotoxicity of two commercial pesticides by their micro and nano size capsules.

The use of nanotechnology in the agrochemical industry has become increasingly popular over the past decade, raising the question of whether these products may represent a risk or benefit compared to their conventional presentations. In this study, we aimed to evaluate the different genotoxic effects of the Complete encapsulated presentation (CEP), the micro encapsulated fraction (MEF), and the nano encapsulated fraction (NEF) of two pesticides (Karate® and Ampligo®) in lymphocytes from human peripheral blood. To test the different fractions, the pesticides were separated by centrifugations by the average size of the capsule, then were characterized by the general composition of the capsule by RAMAN and FTIR spectroscopy and the active ingredient of both pesticides by gas chromatography-mass spectrometry. Each fraction was tested separately and analyzed by comet assay through the tail moment and the percentage of DNA in the tail and the cytokinesis-block micronucleus through their frequency of micronucleus, nucleoplasmic bridges, and nuclear buds. The nuclear division index and the Nuclear Division Cytotoxicity Index were also measured. For both pesticides, the CEP increased the genetic damage observed in the tail moment and percentage of DNA in the tail at all concentrations for both pesticides. However, in the micronucleus test, NEF induced more micronuclei than MEF and CEP in all treatments reducing cell proliferation as the concentration decreased for both pesticides. These results suggested that NEF had more genotoxic effects in both pesticides, increasing the damage to the cells.

Responses of Freshwater Planarian Girardia tigrina to Fipronil-Based Insecticide: Survival, Behavioral and Physiological Endpoints

Fipronil is a pyrazole insecticide used to control undesirable insect populations. Due to its large-scale application, there is the potential for surface waters’ contamination, with toxic action for non-target organisms, and consequent impacts on aquatic ecosystems. Planarians are potential non-target aquatic invertebrates to these insecticides. They are widespread in tropical freshwaters and have been proposed as good candidates to assess the toxic effects of freshwater systems contaminated by insecticides. Thus, the present study aims to evaluate the sublethal concentrations of a fipronil-based insecticide that may affect the planarian physiology. After chronic exposure to Regent 800 WG®, a significant decrease in locomotor velocity (LOEC—6.25 mg·L−1), regeneration of the auricles and photoreceptors (LOEC—3.13 mg·L−1), and reproduction (fecundity—LOEC 12.5 mg·L−1) were observed. The results of our study demonstrate that long-term exposure to a pyrazole insecticide can compromise non-target aquatic invertebrates while reinforcing the need for a better investigation of complementary parameters (such as behavior, regeneration, and reproduction) for a more accurate risk assessment of commercial pesticide toxicity in freshwater systems.

Antifungal Activity and Plant Growth-Promoting Properties of Bacillus mojovensis B1302 against Rhizoctonia Cerealis.

Rhizoctonia cerealis is a worldwide soil-borne pathogenic fungus that significantly infects wheat and causes sharp eyespot in China. However, the biocontrol strains used for the control of Rhizoctonia cerealis are insufficient. In the present study, antagonistic strain B1302 from the rhizosphere of wheat were isolated and identified as Bacillus mojovensis based on their morphological, physiological, and biochemical characteristics, and their 16S rDNA sequence. Culture filtrate of strain B1302 had a broad antifungal spectrum. In order to improve the antifungal activity of B1302, response surface methodology (RSM) was used to optimize the culture conditions. The final medium composition and culture conditions were 13.2 g/L of wheat bran, 14.1 g/L of soybean meal, 224 r/min of rotation speed, 7.50 of initial pH, and 1.5 × 108 CFU/mL of inoculation amount at 35 °C for a culture duration of 72 h. B. mojavensis B1302 inhibited the hyphae growth of R. cerealis and produced hydrolytic enzymes (protease, chitinase, and glucanase), IAA, and had N-fixing potentiality and P-solubilisation capacity. It can also promote wheat seedling growth in potted plants. The disease incidence and index of wheat seedlings were consistent with the effect of commercial pesticides under treatment with culture filtrate. The biocontrol efficacy of culture filtrate was significant—up to 65.25%. An animal toxicological safety analysis suggested that culture filtrate was safe for use and could be developed into an effective microbial fungicide to control wheat sharp eyespot.

The Effects of Commercial Pesticide Formulations on the Function of In Vitro and In Vivo Assay Systems: A Comparative Analysis

Pesticides are commonly used in agriculture and are an important factor of food security for humankind. However, the overuse of pesticides can harm non-target organisms, and, thus, it is vital to comprehensively study their effects on the different metabolic pathways of living organisms. In the present study, enzyme-inhibition-based assays have been used to investigate the effects of commercial pesticide formulations on the key enzymes of the organisms, which catalyze a wide variety of metabolic reactions (protein catabolism, lactic acid fermentation, alcohol metabolism, the conduction of nerve impulses, etc.). Assay conditions have been optimized, and the limitations of the methods used in the study, which are related to the choice of the solvent for commercial pesticide formulations and optical effects occurring when commercial pesticide formulations are mixed with solutions of enzymes and substrates of assay systems, have been revealed. The effects of commercial pesticide formulations on simple chemoenzymatic assay systems (single-enzyme reactions) have been compared to their effects on complex multicomponent molecular systems (multi-enzyme reactions) and organisms (luminescent bacterium). The in vitro assay systems have shown higher sensitivity to pesticide exposure than the in vivo assay system. The sensitivity of the in vitro assay systems increases with the elongation of the chain of conjugated chemoenzymatic reactions. The effects exerted by commercial pesticide formulations with the same active ingredient but produced by different manufacturers on assay system functions have been found to differ from each other.

Effects of commercial pesticides on the nematode biological control agent Pochonia chlamydosporia

ABSTRACT Tomato Solanum lycopersicum plants are exposed to a wide range of pests and diseases in protected cultivation, including root-knot nematodes (RKN), Meloidogyne spp. As the application of chemical nematicides is progressively being restricted in the EU, biological control agents such as Pochonia chlamydosporia are being considered as sustainable alternatives. Nevertheless, success in the control of RKN depends on the compatibility of the fungus with pesticides used to manage other pests and diseases. We tested the in vitro acute and chronic effects of twelve different commercial pesticides used throughout a tomato cropping cycle on P. chlamydosporia. All pesticides significantly inhibited radial growth of the fungus at 22 days, with exception of methiocarb (Mesurol 200), spiromesifen (Oberon), copper-metalaxyl-M (Ridomil Gold R) and oxamyl (Vydate 10L). All fungicides produced significant acute and chronic negative effects on chlamydospore viability. Insecticides methiocarb, spinosad (Spintor) and indoxacarb (Steward) did not affect chlamydospore germination at the tested concentration of active substance (100 mg·L−1) of pesticide in the acute effects test, but all tested pesticides significantly reduced chlamydospore viability in the chronic 6-week-exposure test. Importantly, chlamydospore germination rates recorded were higher in the 12-week than in the 6-week-exposure chronic test, hinting at P. chlamydosporia acclimation or recovery. In view of differences in compatibility of commercial pesticides with P. chlamydosporia, acting on different fungal life stages in acute and chronic processes, these must be carefully selected and the timing of their application considered in the design of crop protection strategies against RKN to improve the biological control success.

Impact of twenty pesticides on soil carbon microbial functions and community composition

Pesticides are known to affect non-targeted soil microorganisms. Still, studies comparing the effect of multiple pesticides on a wide range of microbial endpoints associated with carbon cycling are scarce. Here, we employed fluorescence enzymatic assay and real-time PCR to evaluate the effect of 20 commercial pesticides, applied at their recommended dose and five times their recommended dose, on soil carbon cycling related enzymatic activities (α-1,4-glucosidase, β-1,4-glucosidase, β-d-cellobiohydrolase and β-xylosidase), and on the absolute abundance of functional genes (cbhl and chiA), in three different South Australian agricultural soils. The effects on cellulolytic and chitinolytic microorganisms, and the total microbial community composition were determined using shotgun metagenomic sequencing in selected pesticide-treated and untreated samples. The application of insecticides significantly increased the cbhl and chiA genes absolute abundance in the acidic soil. At the community level, insecticide fipronil had the greatest stimulating effect on cellulolytic and chitinolytic microorganisms, followed by fungicide metalaxyl-M and insecticide imidacloprid. A shift towards a fungal dominated microbial community was observed in metalaxyl-M treated soil. Overall, our results suggest that the application of pesticides might affect the soil carbon cycle and may disrupt the formation of soil organic matter and structure stabilisation.

Decursinol chloroacrylates useful as fungicides

Natural products decursin and decursinol angelate were recently reported as benign fungicides for controlling rice blast. Inspired by the structural similarity of the cumarin compounds and gained hint from the skeletal motifs, we designed and prepared synthetic compounds to increase the natural product efficacy and evaluated their antifungal activities against various plant disease pathogens in vitro. Synthetically prepared compound 4 and 5 indeed suppressed the mycelial growth of B. cinerea, F. oxysporum, P. italicum, and R. quercus-mongolicae. Additionally, compound 5 effectively prevents the growth of C. coccodes and C. parasitica. Furthermore, both 4 and 5 possess better inhibitory activities on spore germination of F. oxysporum and M. oryzae than the natural product decursin and commercial pesticide Iprodione. These results suggest that the effect of the lead compound for plant disease protection can be improved by tuning the structure of the original natural product and decursinol chloroacrylates 4 and 5 are candidates for the control of F. oxysporum and M. oryzae.

Imidacloprid-based commercial pesticide causes behavioral, biochemical, and hematological impairments in Wistar rats

Imidacloprid (IMI) is a neonicotinoid insecticide employed worldwide for crop protection. IMI’s mode of action occurs through the agonism of postsynaptic nicotinic acetylcholine receptors (nAChRs), with high specificity for insect nAChRs although there are reports of mammals’ toxicity. Studies on IMI’s neurotoxicity are not conclusive; therefore, the aim of this study was to evaluate the subchronic toxic effects of an IMI based commercial pesticide on rats. Adult male Wistar rats received an IMI suspension via the oral route at doses of 1.5, 5, and 15 mg/kg for 45 consecutive days. IMI caused an increase in rearing and time spent at the periphery in the locomotor activity test and a decrease in time spent to finish the OX maze task (p < 0.05; ANOVA/Bonferroni). In blood, there was a decrease in mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration (p < 0.05; ANOVA/Bonferroni) and an increase in serum butyrylcholinesterase activity (p < 0.001; ANOVA/Bonferroni). Therefore, subchronic administration of an IMI-based-pesticide caused behavioral and systemic impairments in rats.

Grafted Pullulan Derivatives for Reducing the Content of Some Pesticides from Simulated Wastewater.

The goal of the current article was to obtain data regarding the application of a series of grafted pullulan derivatives, as flocculating agents, for removal of some pesticide formulations from model wastewater. The pullulan derivatives are cationic polyelectrolytes, with various content and length of grafted poly[(3-acrylamidopropyl)-trimethylammonium chloride] chains onto the pullulan (P-g-pAPTAC)]. The commercial pesticides are either fungicide (Bordeaux Mixture) (BM) or insecticides (Decis (Dc)—active ingredient Deltamethrin, Confidor Oil (CO)—active ingredient Imidacloprid, Confidor Energy (CE)—active ingredients Deltamethrin and Imidacloprid and Novadim Progress (NP)—active ingredient Dimethoate). The removal efficiency has been assessed by UV-Vis spectroscopy measurements as a function of some parameters, namely polymer dose, grafted chains content and length, pesticides concentration. The P-g-pAPTAC samples showed good removal efficacy at doseop, more than 94% for BM, between 84 and 90% for DC, CO and CE and around 93% for NP. The maximum percentage removal decreased with the pesticides (DC, CO, CE, NP) concentration declining; no effect of BM concentration in suspension on its removal efficiency process has been noted. Differences indicated by zeta potential and particle size distribution measurements regarding the pesticides removal mechanisms by pullulan derivatives (charge neutralization, bridging, etc.) are discussed.

Effectiveness of Plants Extracts and Mycoinsecticide on Management of Cowpea Flower Thrips Megalurothrips sjostedti (Thysanoptera: Thripidea) under Field Conditions

To promote the use of natural substances for better management of the cowpea thrips Megalurothrips sjostedti, the potential of aqueous extract of Azadirachta indica, Boswellia dalzielii and Metarhizium anisopliae, alone and their combinations in comparison with the synthetic chemical insecticide (Decis) were tested. The experiments were carried out in two cowpea varieties under field conditions within the Sudano-Sahelian agro-ecological zone of Cameroon. Trials were arranged in a completely randomized block design with nine treatments. The nine treatments consisted of a negative control, A. indica; B. dalzielii; M. anisopliae, A. indica+B. dalzielii; M. anisopliae+B. dalzielii; M. anisopliae+A. indica; M. anisopliae+A. indica+B. dalzielii and Decis. Each treatment replicated four times. Vigna unguiculata plants were sprayed from flowering stage thrice with insecticidal products at 5 day intervals. The density of adults and larvae thrips was assessed on 5 flowers per block during 5 days after the last spraying of treatments. Results showed that, there were more thrips on Bafia variety than B125 variety (p&lt;0.0001). All the tested treatment significantly (p&lt;0.0001) reduced the cowpea flower thrips of 30% for A. indica, B. dalzielii and A. indica+B. dalzielii, 75% for M. anisopliae and its various combinations, and of 90% for Decis. Plants extracts, mycoinsecticide and their combinations considerably reduced damage induced by thrips compared to the negative control. A. indica, B. dalzielii, M. anisopliae and their combinations showed ability as natural traitement for the management of thrips in V. unguiculata. These products do not only protect V. unguiculata crop from its major pest, but also preserve the environment from harmful effects induced by the use of synthetic commercial pesticides.

Pesticides and gas production by baker's yeast in bread dough

SummaryPesticide residues might delay food fermentation. The aim of this study was to determine the effect of thirty‐one commercial pesticides (fourteen fungicides; eleven herbicides; one growth regulator; five insecticides) on the fermentative activity of baker's yeast in bread dough and sugared water. Yeast gas production after 3 h at 38 °C in dough or water was slightly inhibited by 10 mg kg−1 of a herbicide containing glufosinate‐ammonium and 100 mg kg−1 of fungicides with tebuconazole or metconazole. At the highest level assayed, 1000 mg kg−1, more than one‐third of the thirty‐one pesticides assayed did not impair baker's yeast gas production. Yeast cells were not inhibited by 300 mg active ingredients kg−1 in a mix of the pesticides, a concentration unlikely to be present in dough considering existing application rates in the field. Dough protected baker's yeast from pesticide residues. In sugared water, sub‐inhibitory concentrations of pesticides stimulated yeast fermentative activity. We conclude that it is unlikely that pesticide residues would impair baker's yeast gas production during bread dough fermentation.

Repellent and toxic effects of Salvia rosmarinus oil against Liriomyza sativae

AbstractThe vegetable leafminer (VLM) Liriomyza sativae Blanchard is a troublesome pest of vegetable and ornamental plants worldwide. Resistance development and environmental pollution from the overuse of chemical insecticides have driven interest in alternative control strategies for this pest. Secondary metabolites derived from aromatic nonhost plants are recognised components of the plant defence system against herbivores. The essential oils derived from aromatic plants not only repel insects but also have toxic effects against various insect pests, yet little is known about their effects against leafminers. The major constituents of the essential oil extracted from rosemary leaves by hydrodistillation were identified by GC–MS. The behavioural responses of VLM adults to the rosemary essential oil (REO) were explored with Y‐tube olfactometer experiments, and the oviposition and feeding deterrent effects of REO against adults were studied using no‐choice cage tests. Dipping methods were used to determine the toxicity of REO and Matrine (a commercial botanical pesticide) against VLM eggs, larvae and pupae, while glass‐vial bioassays were used for adults. The identified major constituents of the cineoliferum chemotype of REO were 1,8‐cineole (23.53%), pinene (23.45%), (S)‐(−)‐verbenone (12.84%) and borneol (7.47%). REO repelled leafminer adults. Sublethal concentrations of REO deterred oviposition and feeding by adults. Adults were more susceptible than other developmental stages to toxicity of REO and Matrine. Female adults were more sensitive than males, based on EC50 values at 24 and 48 hr after treatment. Rosemary essential oil is a behaviour‐modifying stimulus potentially useful in a “push‐pull” strategy for L. sativae control, and as an alternative to synthetic chemical insecticides due to its low toxicity and high efficacy in the control of VLM.

A Continuous Flow Injection/Indirect Photometric Method for the Detection of Fosetyl Aluminum in Commercial Pesticide Formulations

AbstractBecause of their Physico‐chemical characteristics and its composition, the development of new specific analytical methodologies to determine some highly polar pesticides are required. The reported methods demand long analysis time, expensive instruments and prior extraction of pesticide for detection. The current work presents a new flow injection analysis method combined with indirect photometric detection for the determination of Fosetyl‐Aluminum (Fosetyl‐Al) in commercial formulations, with rapid and highly accurate determination involving only construction of manifold system combined with photometric detector without need some of the pre‐treatments to the sample before the analysis such as extraction or separation. The proposed method is based on the reaction between the Fosetyl‐Al with the colorimetric reagent (Aluminon dye) in an aqueous medium of sodium nitrite resulting in the formation of a red complex and its absorbance is measured using the photometric detector. The proposed method included optimization of several parameters such as sodium nitrite concentration, flow rate, sample volume, Aluminon dye concentration, mixing coil and light intensity. The linear range of the detector response was in the range of 0.005–1.8 mmol/L for the sample with r (coefficient of determination) 0.9909, R2 (correlation coefficient) 0.9954 at 95 % and 0.0041 mmol/L as a limit of detection. The relative standard deviation was less than 1.5 % for 0.005 mmol/L of the analyte (n=11). The proposed method was validated and applied successfully for the determination of Fosetyl‐Al in commercial formulations and can be used as an alternative method for quality control assessment.

Emission of volatile organic compounds (VOCs) from application of commercial pesticides in China

Applying pesticides can result in emissions of volatile organic compounds (VOCs), but little is known about VOC emission characteristics and the quantities in particular regions. We investigated the use of pesticides in China based on a large-scale survey of 330 counties in 31 provinces and evaluated the national pesticide VOC emission potentials based on thermogravimetric analysis of 1930 commercial pesticides. The results showed that herbicides were the most extensively used pesticide category in China, accounting for 43.47%; emulsifiable concentrate (EC), suspension concentrate, and wettable powder were the dominant pesticide formulations, with proportions of 26.75%, 17.68%, and 17.31%, respectively. The VOC emission potential coefficient (EP) of the liquid formulations was higher than the solid formulations, and the maximum mean EP was 45.59% for EC and the minimum was 0.76% for WP. Among 437 high-VOC pesticide products used in China, EC accounted for 83.52%, and 16.93% of those contained abamectin. The total VOC emissions derived from commercial pesticides in China were 280 kt (kilotons) in 2018, and 65.35% of the contribution was derived from EC. Shandong, Hunan, and Henan were the three provinces with the highest pesticide VOC emissions (>21 kt/y). The emission rate of VOCs from pesticides was 24.80 t/d in China, which was higher than in San Joaquin Valley, California. These findings suggest that some comprehensive measures (e.g., perfecting pesticide management policy, strict supervision for pesticide production and use, and strengthening pesticide reduction publicity) should be taken to reduce VOC emissions from pesticide applications.

Highly Sensitive Fluorescent Biosensor Based on Acetylcholinesterase and Carbon Dots–Graphene Oxide Quenching Test for Analytical and Commercial Organophosphate Pesticide Detection

Graphical Abstract