Triazole Pesticides Research Articles

Comparative evaluation of solid-phase extraction and in-tube liquid-liquid extraction for determination of triazole pesticides in water samples

ABSTRACT In this study, we have compared two extraction methods (in-tube liquid-liquid extraction and solid-phase extraction) in terms of precision, recovery percentage and time. Parameters, influencing the extraction efficiency, such as nature and volume of extraction solvent and pH nature were optimised. Under the optimum conditions, results showed that SPE is certainly more effective than in-tube liquid-liquid extraction. In this method, a volume of the sample solution is acidifed to pH 4.0 and then passed through C18 cartridge, the absorbed analytes are eluted by an appropriate solvent (acetonitrile), the cartridge was centrifuged and finally, the elute was recovered. The extract was evaporated directly with a weak nitrogen stream. The obtained extract was injected into gas chromatography-Mass spectrometry. The results of the validation indicated that this method provided an excellent linearity with correlation coefficients ranged from 0.997 to 0.999; low limits of detection and quantification in the ranges of 0.01–0.04 μg.L−1 and 0.03–0.14 µg.L−1 respectively. Extraction recoveries ranged from 79% to 94%, Enrichment factors in the range of 158–188 and Relative Standard Deviations are less than 3%. At the end, the proposed procedure was successfully applied to the analysis of real samples, the average concentrations of triazole pesticides are 0.51 µg.L−1 and 8.79 µg.L−1. The predominant triazoles founded are Myclobutanil (1.61–8.79 µg.L−1) and Penconazole (0.99–6.89 µg.L−1). Results show that all recorded triazole concentrations exceed the values standardised by the regulations.

Influence of Triazole Pesticides on Wine Flavor and Quality Based on Multidimensional Analysis Technology.

Triazole pesticides are widely used to control grapevine diseases. In this study, we investigated the impact of three triazole pesticides—triadimefon, tebuconazole, and paclobutrazol—on the concentrations of wine aroma compounds. All three triazole pesticides significantly affected the ester and acid aroma components. Among them, paclobutrazol exhibited the greatest negative influence on the wine aroma quality through its effect on the ester and acid aroma substances, followed by tebuconazole and triadimefon. Qualitative and quantitative analysis by solid-phase micro-extraction gas chromatography coupled with mass spectrometry revealed that the triazole pesticides also changed the flower and fruit flavor component contents of the wines. This was attributed to changes in the yeast fermentation activity caused by the pesticide residues. The study reveals that triazole pesticides negatively impact on the volatile composition of wines with a potential undesirable effect on wine quality, underlining the desirability of stricter control by the food industry over pesticide residues in winemaking.

A sensitive determination of triazole pesticides in grape juice by combining solid phase extraction–dispersive liquid–liquid microextraction followed by gas chromatography–flame ionisation detection

ABSTRACT In this study, a solid phase extraction method followed by dispersive liquid–liquid microextraction has been developed for the extraction and preconcentration of five triazole pesticides (penconazole, hexaconazole, diniconazole, tebuconazole, and triticonazole) in grape juice. Initially, a high volume of the sample solution is passed through the solid phase extraction cartridge and then the absorbed analytes are eluted by an appropriate solvent (methanol) which acts as a dispersive solvent in the following microextraction procedure. Then, the eluate is mixed with 1,1,2,2,–tetrachloroethane as an extraction solvent and the mixture is rapidly injected into sodium chloride solution. After centrifugation, an aliquat of the obtained sedimented phase is injected into gas chromatography–flame ionisation detection. Some effective parameters on performance of the method such as washing and elution solvents type and volume, extraction solvent, etc were investigated. Under optimum conditions (sample solution volume, 100 mL; flow rate, 10 mL min–1; elution solvent (volume), methanol (1.0 mL); extraction solvent (volume), 1,1,2,2–tetrachlorothene (25 µL); aqueous phase in DLLME, sodium chloride solution (30%, w/v); and centrifugation time (speed), 5 min (3000 rpm)), the method showed high enrichment factors (4101–9566) and low limits of detection (0.053–0.890 ng mL–1) and quantification (0.178–2.96 ng mL–1). Finally, ten grape juices were successfully analysed by this method and hexaconazole was detected in some of them in the concentration range of 19–29 ng mL–1.

Determination of Triazole Pesticides in the Surface Water of the Medjerda River, Tunisia

Water is an essential part of daily life for every human and a source of wealth. The Medjerda River is the most important river and the largest water resource in Tunisia. It is used as a potable water supply and for agriculture as well as an important aquatic life place. The objective of this work is to investigate the distribution of fifteen triazole pesticides in water samples collected from the Medjerda River. The extraction of water samples was performed by liquid–liquid extraction with ethyl ether. Gas chromatography coupled to mass spectrometry (GC-MS) was used to perform the qualitative and quantitative determinations. The average concentrations of triazole pesticides were 1.47 and 24.27 ng L−1. For triticonazole the concentrations ranged between 0.05 and 6.80 ng L−1. The predominant triazole pesticides in the surface water were tebuconazole (0.19 to 8.04 ng L−1) and fluquinconazole (0.97 to 6.96 ng L−1). The levels of triazole pesticides investigated in this study pose no threat to humans and the aquatic environment. These concentrations are generally similar to the background levels from the Mediterranean Sea.

Modification and setting of maximum residue levels for mefentrifluconazole in various crops.

In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant BASF Agro BV Arnhem submitted a request to the competent national authority in Austria to set and modify the maximum residue levels (MRLs) for the active substance mefentrifluconazole in various products of plant and animal origin. The data submitted in support of the request were found to be sufficient to derive MRL proposals for pome fruits, apricots, cherries, peaches, plums, grapes, potatoes, sweet corns, maize, sunflower seeds, rapeseeds, sugar beet roots, swine liver, bovine kidney and ruminant milk. Adequate analytical methods for enforcement are available to control the residues of mefentrifluconazole in plant and animal matrices at the validated limit of quantification (LOQ) of 0.01 mg/kg. A consumer risk assessment was performed for mefentrifluconazole. The short‐term and the long‐term intake of parent mefentrifluconazole resulting from the intended uses is unlikely to present a risk to consumer health. EFSA also performed an indicative risk assessment for the following four metabolites of mefentrifluconazole, which are called triazole derivative metabolites (TDMs): triazole alanine (TA), triazole lactic acid (TLA), triazole acetic acid (TAA) and 1,2,4‐triazole (1,2,4‐T). These metabolites are common metabolites for a number of triazole fungicides. For the TDM risk assessment, EFSA took into account not only data from the intended uses of mefentrifluconazole but also the information available from various triazole pesticides previously assessed. Overall, the estimated exposure for TDMs did not exceed the toxicological reference values, noting that the consumer exposure assessments for the TDMs are affected by uncertainties related to the data gaps identified in the EU peer review of confirmatory data for TDMs.

Application of temperature-assisted tandem dispersive liquid–liquid microextraction for the extraction and high preconcentration of triazole pesticides

ABSTRACT An efficient and reliable sample pretreatment approach termed as temperature-assisted tandem dispersive liquid–liquid microextraction has been developed for the extraction of five triazole pesticides from aqueous samples prior to their quantification by gas chromatography–flame ionisation detection. The suggested approach comprises two successive dispersive liquid–liquid microextraction approach. For performing procedure, the first temperature of high volume of aqueous solution is thermostated at an elevated temperature and after that, the mixture of disperser and extraction solvents is quickly injected into it. After cooling the solution with tap water, phase isolation is hastened by centrifuging. The whole of sedimented phase is taken and after mixing with another disperser solvent is employed in the following microextraction approach. The validation outcomes indicated that the approach provided low limits of detection and quantification (0.08–0.13 and 0.24–0.48 ng mL−1, respectively). Extraction recoveries and enrichment factors and were in the ranges of 97–100%and 9715–9970, respectively. Relative standard deviations were ≤6%. At the end, several aqueous samples were analysed employing the suggested approach and penconazole and hexaconazole were detected in them.

Enantiomeric Separation of Chiral Triazole Pesticides by a mono-6-(4-Nitrophenyl)-ureido-β-cyclodextrin-Bonded Stationary Phase Using High-Performance Liquid Chromatography

A mono-6-(4-nitrophenyl)-ureido-β-cyclodextrin-bonded chiral stationary phase (NCDSP), containing π-electron withdrawing groups, was prepared by immobilizing a self-prepared mono-6-(4-nitrophenyl)-ureido-β-cyclodextrin ligand onto ordered mesoporous silica gel SBA-15, on which the ligand was synthesized by the reaction of mono-6-amino-β-cyclodextrin with 4-nitrophenylisocyanate. The structure of NCDSP was characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis and solid nuclear magnetic resonance. The introduction of electron-withdrawing (π-acidic) groups facilitated the separation of the π-electron-rich (π-basic) triazole chiral pesticides. In addition, the ureido group linkage allowed NCDSP to be a hydrogen bond-accepting and -donating chiral station phase and prevented the hydrolysis associated with nitrobenzoate and nitrophenylcarbamate linkages. As a result, the enantioseparations of nine triazole pesticides were achieved using NCDSP. Meanwhile, the chromatographic conditions, such as the pH and the composition of mobile phases, were investigated in detail. Moreover, in a comparative study with a cyclodextrin stationary phase (CDSP), the NCDSP provided higher enantioselectivity. Baseline separations for most of these triazoles on NDCSP were observed in relatively short times from 10 to 20 min. The highest resolution achieved was 2.87. Otherwise, incomplete enantiomeric separation was observed on the CDSP with a maximum resolution of less than 1.18. For the NCDSP, in addition to the inclusion effect, the π-π interaction between the electron-deficient stationary phase and the electron-donating triazoles significantly contributed to the chiral separation. This work reports a simple and convenient method for the preparation of the NCDSP with the rapid separation of chiral triazole pesticides.

Magnetic partially carbonized cellulose nanocrystal-based magnetic solid phase extraction for the analysis of triazine and triazole pesticides in water.

Magnetic partially carbonized cellulose nanocrystals (MPC-CNC) were obtained by sulfuric acid treatment of microcrystalline cellulose (MCC) and then loaded with magnetic Fe3O4 nanoparticles. The material is shown to be a viable material for magnetic solid phase extraction of triazine and triazole pesticides from water. The pesticides (specifically: simazine, ametryn, prometryn, terbutryn, atrazine, triadimenol, epoxiconazole, myclobutanil, triadimefon and tebuconazole) were quantified by ultra HPLC in tandem with a triple quadrupole mass spectrometry (UHPLC-MS/MS). The effects of NaCl concentration, amount of adsorbent, vortex time, sample volume and pH value on extraction efficiency were optimized by Plackett-Burman design and Box-Behnken design methods. Under the optimal conditions, the method shows the following figures of merit: (a) Linear responses in the range from 0.02-10μgL-1; (b) detection limits between 2.2 to 6.1ngL-1 (for S/N = 3); (c) recoveries from spiked samples of 73.7-117.1% with relative standard deviations (RSDs) of 2.0-15.7%; and (d) an enrichment factor of 75. The method was successfully applied to the determination of the pesticides in five environmental water samples. Graphical abstract Schematic representation of the process of magnetic solid phase extracting pesticides in water using MPC-CNC. MCC-microcrystalline cellulose; PC-CNC- partially carbonized cellulose nanocrystals; MPC-CNC-magnetic partially carbonized cellulose nanocrystals.

Preparation of a stilbene diamido-bridged bis(β-cyclodextrin)-bonded chiral stationary phase for enantioseparations of drugs and pesticides by high performance liquid chromatography

A stilbene diamido-bridged bis(β-cyclodextrin) was synthesized via the reaction between 4,4′-stilbene dicarboxylic acid and 6-deoxy-6-amino-β-cyclodextrin. Then it was bonded onto the surface of an ordered mesoporous SBA-15 to obtain a novel bridged bis(β-cyclodextrin)-bonded chiral stationary phase (SBCDP). The structures of the bridged bis(β-cyclodextrin) and SBCDP were characterized by the mass spectrometry, nuclear magnetic resonance, infrared spectroscopy, elemental analysis and thermogravimetric analysis. The chromatographic performance of SBCDP was systematically evaluated by separating 23 racemic drugs and pesticides, including trimeprazine, praziquantel, flavanones, β-blockers and triazole pesticides in the reversed-phase chromatography or the polar organic mode. The chromatographic conditions that affect the enantioselectivity or diasterioselectivity of SBCDP were investigated in detail, including the mobile phase composition, pH value and column temperature. As a result, all tested analytes were resolved on SBCDP with high resolutions (1.51∼5.15) within about 25 min, and the enantioseparation resolutions of flavanone and imazalil were up to 5.15 and 4.38, respectively. Compared with the native β-cyclodextrin stationary phase (CDCSP), the SBCDP had a better chromatographic performance in enantioselectivity and diasterioselectivity. For example, enantiomers of trimeprazine, praziquantel, flavanone and imazalil those could not be separated by CDCSP, were separated by SBCDP with high resolutions. Unlike the small cavity (0.65 nm) of native CD, the bridging linker of the bridged bis(β-CD) supplied a well-organized “pseudo-cavity”, and combined two native CDs as an organic whole, which could synergistically encapsulate and complex some bulky analytes, making the chiral discrimination of SBCDP more precise. Moreover, we also found that SBCDP possessed high enantioselectivity and diastereoselectivity over a wide range of temperature (30∼60 °C), which made the fast analysis possible. As a new chiral separation material, SBCDP may have wider applications in analysis of chiral compounds.

Heterogeneous oxidation of two triazole pesticides (diniconazole and tebuconazole) by OH-radicals and ozone

Tebuconazole (Tbz) and diniconazole (Dnz) were deposited as thin film on quartz plaques. They were submitted to OH-radicals and ozone and their kinetic was measured. OH-radical oxidation was performed relative to a reference whose rate constant is well known. Terbuthylazine (Tbt) and Chlorpyriphos Ethyl (Clp) were chosen as reference for Tbz and Dnz kinetics determination, respectively. OH-radical rate constants of Tbz and Dnz were found to be: kOH+Tbz = (1.7 ± 0.2) 10−13 cm3 molecule−1 s−1 and k OH+Dnz = (1.74 ± 1.21) 10−12 cm3 molecule−1 s−1, respectively. Ozone heterogeneous oxidation rate constants were determined in an absolute way: kO3+Tbz = (0.5 ± 0.2) 10−20 cm3 molecule−1 s−1; kO3+Dnz = (1.4 ± 0.2) 10−19 cm3 molecule−1 s−1.Dnz is ten times more reactive toward OH-radicals than Tbz and 27 times more reactive than Tbz toward ozone maybe because of the presence of a double bond in Dnz. Lifetimes of Tbz and Dnz on quartz like surfaces are against OH-radicals are of 68 days and 8 days, respectively and 4 months and several years against ozone, respectively.

Emerging Fungal Infections: New Patients, New Patterns, and New Pathogens.

The landscape of clinical mycology is constantly changing. New therapies for malignant and autoimmune diseases have led to new risk factors for unusual mycoses. Invasive candidiasis is increasingly caused by non-albicans Candida spp., including C. auris, a multidrug-resistant yeast with the potential for nosocomial transmission that has rapidly spread globally. The use of mould-active antifungal prophylaxis in patients with cancer or transplantation has decreased the incidence of invasive fungal disease, but shifted the balance of mould disease in these patients to those from non-fumigatus Aspergillus species, Mucorales, and Scedosporium/Lomentospora spp. The agricultural application of triazole pesticides has driven an emergence of azole-resistant A. fumigatus in environmental and clinical isolates. The widespread use of topical antifungals with corticosteroids in India has resulted in Trichophyton mentagrophytes causing recalcitrant dermatophytosis. New dimorphic fungal pathogens have emerged, including Emergomyces, which cause disseminated mycoses globally, primarily in HIV infected patients, and Blastomyces helicus and B. percursus, causes of atypical blastomycosis in western parts of North America and in Africa, respectively. In North America, regions of geographic risk for coccidioidomycosis, histoplasmosis, and blastomycosis have expanded, possibly related to climate change. In Brazil, zoonotic sporotrichosis caused by Sporothrix brasiliensis has emerged as an important disease of felines and people.

Pesticide Toxicity Profile: Triazole Pesticides

This document provides a general overview of human toxicity, provides a listing of laboratory animal and wildlife toxicities and a cross reference of chemical, common and trade names of triazole pesticides registered for use in Florida. This document is PI-68, one of a series of the Pesticide Information Office, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date September 2005.

Cumulative probabilistic risk assessment of triazole pesticides in Belgium from 2011-2014

ABSTRACTPesticide residues in food can lead to harmful toxic effects when exposed. Some of these compounds have a common Mode of Action and thus elicit a similar biological response. This paper considers the triazoles, a class of widely used fungicides exhibiting the same short-term (acute) and long-term (chronic) response in humans. We examined Belgian pesticide residue data from 2011–2014 and coupled these with the results of the Belgian food consumption survey of 2004. Cumulative probabilistic risk assessment was done using the Monte Carlo Risk Assessment 8.0 web application. The European Food Safety Authority (EFSA) published a guidance document that proposes both optimistic and pessimistic scenarios for dietary exposure assessment. Other than those two, a third, more balanced, scenario was simulated and showed an exposure right in between the EFSA scenarios. In the optimistic scenario, the foods with the highest measured residues in the residue data contributed the most to the total health risk. In the balanced and pessimistic scenarios, the highest contribution to the total health risk was made by active ingredients with a high sampling rate and/or a high consumption rate. No significant trends were observed in the health risk through 2011 to 2014, and the exposure distribution showed no health risks for the extreme consumers, with one exception in 2012.

Limitations of pesticide genotoxicity testing using the bacterial in vitro method

The results of genotoxicity assessment of 115 technical grade pesticide products (61 names) with the Ames test and mammalian erythrocyte micronucleus test in vivo are presented. In most cases, unidirectional results were found. However, some pesticides belonging to classes of neonicotinoids, derivatives of phenylurea, glycine and phenoxycarboxylic acids showed genotoxic effects only under in vivo conditions. All observed effects were statistically significant and dose-depended but were only slightly beyond the upper limit of the historical negative control. Pendimethalin (dinitroaniline pesticide) showed positive results only in Ames test. Furthermore, the limitations of Ames test related to the high cytotoxicity of pesticides against bacterial cells were shown (e.g. bipyridylium derivatives, chlorothalonils, dithiocarbamates, quinones, phenyl pyridinamines and sulphonylureas). But many pesticides possessing the highest cytotoxic activity against bacterial cells have shown low toxicity in vivo (MTD > 2000 mg/kg b.w.). On the other hand, all of the tested neonicotinoids, organophosphates, pyrethroids, phenoxycarboxylic acid derivatives were highly toxic to mice but non-cytotoxic against microbial cells. Triazole pesticides exerted toxicity to the target organ (bone marrow). Therefore, these findings suggest that genotoxicity assessment using at least two methods is needed for reliable evidence of the safe use of pesticides.

Polyoxometalate-based ionic liquid coating for solid phase microextraction of triazole pesticides in water samples

ABSTRACTIn the study, the polyoxometalate-based ionic liquid (POM-IL) was prepared. The prepared nanomaterial was immobilized onto a stainless steel wire for fabrication of the solid phase microextraction (SPME) fiber. The applicability of this coating was assessed employing a laboratory-made SPME device and gas chromatography with mass spectrometry (GC–MS) for the extraction of six triazole pesticides (penconazole, hexaconazole, diniconazole, tebuconazole, triticonazole, and difenconazole) from the headspace of aqueous samples. A series of parameters that affect the performance of microextraction, such as fiber coating, extraction time, stirring rate, ionic strength, pH, desorption temperature, and desorption time, were thoroughly investigated. In optimum conditions, the repeatability for one fiber (n = 3), expressed as relative standard deviation, was between 4.3% and 8.3% for the test compounds. The detection limits for the studied compounds were between 7 and 40 pgmL−1.

Chiral separation of six triazole pesticide enantiomers by ultra-performance convergence chromatography and residue determination in cucumber

The separation of six triazole pesticide enantiomers (TPEs) by ultra-performance convergence chromatography (UPC2) was attempted, and residue analytical methods for these TPEs in cucumber were established. The triazole pesticides were triadimefon, triadimenol, hexaconazole, tebuconazole, bitertanol, and myclobutanil. The sample was extracted with acetonitrile and cleaned up using graphitized carbon black (GCB), a Florisil-phase extraction column, and the QuEChERS method. The treated extract was separated on an Acquity Terifoil AMY1 chromatographic column, with gradient elution using a mixture of supercritical CO2 and methanol or ethanol-isopropanol as the mobile phase. The residues of the six TPEs were quantified by the external standard method. The limits of quantitation (S/N>10) of these TPEs in cucumber were 0.1 mg/kg. The recoveries of the TPEs in cucumber at three spiked levels of 0.1, 0.2, and 0.5 mg/kg ranged from 65.1% to 116% with relative standard deviations (RSDs) of 1.0%-9.6%. The developed method facilitated the enantioseparation of the six TPEs and the accurate estimation of their residues in the cucumber matrix. This method is expected to play an important role in the production and utilization of chiral pesticides, as well as the establishment of relevant laws and regulations.

Maximum tolerated doses and erythropoiesis effects in the mouse bone marrow by 79 pesticides' technical materials assessed with the micronucleus assay.

Effects of technical materials of pesticide active ingredients, belonging to various chemical classes, on erythropoiesis in mouse bone marrow were studied as part of the research on the pesticide mutagenic activity in micronucleus test. The purpose of the present study was to estimate the toxic action of the test substances on the target organ and the validity of the results of the micronucleus assay under conditions of erythropoiesis suppression. It was demonstrated that intragastrically administrated triazole pesticides reached bone marrow (target organ where micronucleus induction was assessed) and exerted an inhibitory effect on erythropoiesis. The effects of triazole pesticides were enhanced in the following order: difenoconazole ≤ tebuconazole < cyproconazole < flutriafol. Furthermore, an association between structural features of molecules and specific target organ activity of the test pesticides was observed. Based on the data on the general toxicity and the results of the evaluation of the effects on erythropoiesis, the maximum tolerated doses (MTDs) of 79 different technical materials of pesticides for CD-1 mice were determined.

Microwave‐assisted‐demulsification dispersive liquid–liquid microextraction for the determination of triazole fungicides in water by gas chromatography with mass spectrometry

A novel microwave-assisted-demulsification dispersive liquid-liquid microextraction technique was established for determination of three triazole fungicides in environmental water samples by gas chromatography with mass spectrometry. Importantly, microwave irradiation has been applied in demulsification to achieve the phase separation and enrichment of triazole fungicides in water samples successfully with low-density toluene as extractant. The experimental variables, including microwave power, microwave time, ultrasonic time, type and volume of extraction solvent, and effect of salting out were investigated. Under the optimized conditions, the method showed good linearity for myclobutanil, tebuconazole, and difenoconazole in the range of 1-100μg/L. The limits of detection and the limits of quantification were within the range of 0.14-0.27 and 0.47-0.90μg/L, respectively. The suitable enrichment factors for three triazole pesticides were in the range of 425-636. The recoveries were between 89.3 and 108.7%, and the relative standard deviations were from 5.4 to 8.6%. Finally, environmental water samples were used to verify the applicability of the proposed method for analysis of triazole fungicides targets. It can be concluded that the developed microwave-assisted-demulsification dispersive liquid-liquid microextraction gas chromatography with mass spectrometry method was a rapid, efficient, reliable, and environmental friendly way for analysis of triazole fungicides in water.

Multiresidue Determination of Carbamate, Organophosphate, Neonicotinoid and Triazole Pesticides in Roasted Coffee Using Ultrasonic Solvent Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

Background: A simple and effective extraction method based on ultrasonic solvent extraction and liquid-liquid microextraction (as the cleaning step) was developed to determine seven pesticide residues in roasted coffee (Coffea arabica) using ultra-performance LC-tandem MS. Objective: Different parameters of the method were evaluated, including solvent type and amount and sonication time. The best results were obtained using 1.0 g roasted coffee and acetonitrile (5 mL) as the extraction solvent with sonication for 15 min. The method was validated using roasted coffee samples fortified with pesticides at different concentration levels (0.1, 0.2, 0.3, and 0.5 μg/kg). Average recoveries (three replicates) ranged from 74.3 to 99.9%, with RSDs between 0.7 and 10.2%. Results: The method showed good linearity for all the pesticides studied, with correlation coefficients >0.99. The detection limits ranged from 0.02 to 0.05 μg/kg, and the quantification limit for all the compounds was 0.10 μg/kg. The proposed method was applied for analysis of the compounds in commercial coffee samples from a producer in Minas Gerais State, Brazil. No residues of the pesticides were detected in the samples. Highlights: Ultrasonic solvent extraction was effective in the analysis of pesticides in roasted coffee.

Influence of triazole pesticides on tillage soil microbial populations and metabolic changes

Pesticides are generally applied to agricultural soil to control crop diseases, with the critical goal of preventing yield loss and optimizing economic returns. However, the excessive utilization of pesticides in agriculture is a severe environmental and human health problem. In the present study, effect of triazole based fungicide, propiconazole on soil physicochemical properties, stimulatory impact of propiconazole residue on soil microbial communities and soil enzyme activities (phosphatise and urease) in contaminated red sandy loam and deep black soils of paddy (Oryza sativa L.) fields at different concentrations were evaluated. The liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis showed high levels of propiconazole residues of 434 and 426 ng g−1 in red sandy loam and deep black soils, respectively. A total of 27 bacterial and 18 fungal strains were isolated from propiconazole-contaminated soils, identified by molecular markers and had their sequences deposited in the GenBank. We observed a pronounced increase in soil microbial growth, and urease and phosphatase activities at lower propiconazole concentrations up to 2 weeks post-treatment. On the contrary, the microbial growth and urease and phosphatase activities were relentlessly reduced at higher propiconazole concentrations and a long incubation period after 2 to 4 weeks of post-treatment. Overall, it was concluded that the concentration-dependency and incubation period of propiconazole would enhance the growth and activity of soil microbes and enzymes respectively and the higher application will be detrimental to the soil health.