Metabolite 6-chloronicotinic Acid Research Articles

Microbial-based metabolites associated with degradation of imidacloprid and its impact on stress-responsive proteins.

Imidacloprid (IMD), a neonicotinoid insecticide, is intensively used in agricultural fields for effective protection against aphids, cane beetles, thrips, stink bugs, locusts, etc., is causing serious environmental concerns. In recent years, seed treatment with Imidacloprid is being practiced mainly to prevent sucking insect pests. In India, due to the increase in application of this insecticide residue has been proven to have an impact on the quality of soil and water. In view of this, the current investigation is focussed on sustainable approach to minimize the residual effect of IMD in agricultural fields. The present study reveals a most promising imidacloprid resistant bacterium Lysinibacillus fusiformis IMD-Bio5 strain isolated from insecticide-contaminated soil. The isolated bacterial strain upon tested for its biodegradation potential on mineral salt medium (MSM) showed a significant survival growth at 150g/L of IMD achieved after 3 days, whereas immobilized cells on MSM amended with 200g/L of IMD as the sole carbon source provided degradation of 188 and 180g/L of IMD in silica beads and sponge matrices, respectively. The liquid chromatography mass spectrometry was performed to test the metabolite responsive for IMD biodegradation potential of L. fusiformis IMD-Bio5 which showed the induced activity of the metabolite 6-Chloronicotinic acid. Furthermore, as compared to the untreated control, the Lysinibacillus fusiformis IMD-Bio5 protein profile revealed a range of patterns showing the expression of stress enzymes. Thus, results provided a most effective bacterium enabling the removal of IMD-like hazardous contaminants from the environment, which contributes to better agricultural production and soil quality, while long-term environmental advantages are restored.

Imidacloprid-induced stress affects the growth of pepper plants by disrupting rhizosphere-plant microbial and metabolite composition

Overusing imidacloprid (IMI) has been found to impede secondary metabolism and hinder plant growth. The impact of IMI stress on the interaction between metabolites, rhizosphere, and plant-microbe dispersion through various pathways in pepper plants has not been extensively studied. This study investigated the effects of IMI on plant signaling components, secondary metabolic pathways, and microbial communities in the rhizosphere and phyllosphere. Here, the distribution of IMI and its metabolites (6-chloronicotinic acid, IMI-desnitro, 5-hydroxy-IMI, IMI-urea, and IMI-olefin) was primarily observed in the pepper plant leaves. A rise in IMI concentration had a more significant inhibitive effect on the metabolism of pepper leaves than on pepper roots. The findings of non-target metabolomics indicated that IMI exposure primarily suppresses secondary metabolism in pepper plants, encompassing flavones, phenolic acids, and phytohormones. Notably, the IMI treatment disrupted the equilibrium between plants and microbes by decreasing the population of microorganisms such as Vicinamibacteria, Verrucomicrobiae, Gemmatimonadetes, and Gammaproteobacteria in the phyllosphere, as well as Vicinamibacteria, Gemmatimonadetes, Gammaproteobacteria, and Alphaproteobacteria in the rhizosphere of pepper plants. The study demonstrates that overexposure to IMI harms microbial composition and metabolite distribution in the rhizosphere soil and pepper seedlings, inhibiting plant growth.

Simultaneous determination of ten neonicotinoid insecticides and a metabolite in human whole blood by QuEChERS coupled with UPLC-Q Exactive orbitrap high-resolution mass spectrometry

Since neonicotinoid insecticides are now the most extensively used insecticides worldwide, there are increasing cases of neonicotinoid poisoning. A rapid and sensitive method was developed for the determination of ten neonicotinoid insecticides and a metabolite 6-chloronicotinic acid in human whole blood. The types and amounts of extraction solvent, salting-out agent, and adsorbent in the QuEChERS method were optimized by comparing the absolute recoveries of 11 analytes. The separation was performed on an Agilent EC18 column with the gradient elution with 0.1% formic acid in water and acetonitrile as the mobile phase. The quantification was achieved by Q Exactive orbitrap high-resolution mass spectrometry under parallel reaction monitoring scan mode. The 11 analytes showed good linearity with R2 ≥ 0.9950, LODs ranging from 0.01 μg/L to 0.30 μg/L, and LOQs from 0.05 μg/L to 1.00 μg/L. The recoveries ranged from 78.3% to 119.9% at low, medium, and high spiked concentrations of blank blood, with matrix effects ranging from 80.9% to 117.8%, inter-day RSDs from 0.7% to 6.7%, and intra-day RSDs from 2.7% to 9.8%. The method was furthermore applied to a real case of neonicotinoid insecticide poisoning to demonstrate its feasibility. The proposed method is suitable for the rapid screening of neonicotinoid insecticides in poisoned human blood in the field of forensic science, as well as monitoring of neonicotinoid insecticide residues in humans in the field of environmental safety, compensating for a lack of studies on neonicotinoid insecticide determination in biological samples.

Quantitation of 6-chloronicotinic acid and 2-chloro-1,3-thiazole-5-carboxylic acid and their glycine conjugates in human urine to assess neonicotinoid exposure

Neonicotinoids and neonicotinoid-like compounds (NNIs) are widely used insecticides and their ubiquitous occurrence in the environment requires methods for exposure assessment in humans. The majority of the NNIs can be divided into 6-chloropyridinyl- and 2-chlorothiazolyl-containing compounds, suggesting the formation of the group-specific metabolites 6-chloronicotinic acid (6-CNA), 2-chloro-1,3-thiazole-5-carboxylic acid (2-CTA), and their respective glycine derivatives (6-CNA-gly, 2-CTA-gly). Here, we developed and validated an analytical method based on gas chromatography coupled to mass spectrometry (GC-MS/MS) to simultaneously analyze these four metabolites in human urine. As analytical standards for the glycine conjugates were not commercially available, we synthesized 6-CNA-gly, 2-CTA-gly, and their 13C2,15N-labeled analogs for internal standardization and quantitation by stable isotope dilution. We also ensured chromatographic separation of 6-CNA and its isomer 2-CNA. Enzymatic cleavage during sample preparation was proven unnecessary. The limits of quantitation were between 0.1 (6-CNA) and 0.4 μg/L (2-CTA-gly) and the repeatability was satisfactory (coefficient of variation was <19% over the calibration range). We analyzed 38 spot urine samples from the general population and were able to quantify 6-CNA-gly in 58% of the samples (median 0.2 μg/L). In contrast, no 6-CNA could be detected. The results are in line with well-known metabolic pathways specific in humans, that, compared to rodents, favor the formation and excretion of phase–II–metabolites (glycine derivatives) rather than phase-I metabolites (free carboxylic acids). Nevertheless, the exact source of exposure (i.e., the specific NNI) remains elusive in the general population, may even vary quantitatively between different NNIs, and also might be regional specific based on the respective use of individual NNIs. In sum, we developed a robust and sensitive analytical method for the determination of four group-specific NNI metabolites.

Trace determination of imidacloprid and its major metabolites in wheat-soil system.

Trace analysis method is a reliable basis for studying the translocation and metabolism of imidacloprid used as an insecticide in wheat, and it clarifies whether biologically active metabolites including residual imidacloprid, have long-lasting insecticidal potency against wheat aphids under seed treatment during the entire growth period. In this study, a highly sensitive analytical method was established to determine the residues of imidacloprid and its six metabolites (5-hydroxy imidacloprid, imidacloprid olefin, imidacloprid guanidine, imidacloprid urea, 6-chloronicotinic acid, and imidacloprid nitrosimine) in wheat-soil systems, such as in wheat leaves, wheat ears, wheat grains, roots, and soil. All the compounds were extracted using an ACN:water (8:2, v/v) mixture and purified by dispersive solid-phase extraction. The average recoveries ranged from 74.4% to 109.5% for all matrices, with intra- and inter-day variations of less than 14.9%. The limit of quantitation was in the range of 0.001-0.005 mg/kg. The method is demonstrated to be sensitive and accurate for monitoring imidacloprid and its metabolites at trace levels during the entire growth period under field conditions.

Determination of flupyradifurone and its metabolite in postmortem blood by liquid chromatography-tandem mass spectrometry

Flupyradifurone is a new insecticide that is being in place of neonicotinoid insecticide. A simultaneous analytical method was developed and validated for flupyradifurone and its metabolite, 6-chloronicotinic acid in blood by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The developed method was applied to an actual fatal case for the identification and quantification of flupyradifurone and 6-chloronicotinic acid in blood. Extraction of flupyradifurone and 6-chloronicotinic acid form heart and peripheral blood was performed using solid phase extraction with Oasis HLB cartridge. Flupyradifurone-d5 was used as an internal standard. The flupyradifurone and 6-chloronicotinic acid were separated using a Synergi 2.5 μ Fusion-RP column 50 × 2.0 mm, 2.5 μm), and column temperature were kept at 40 °C with a flow rate of 0.4 mL/min. Mass analysis was performed on a QTRAP mass spectrometer in negative electrospray ionization (ESI) mode. This method was validated for linearity, precision, accuracy and recovery for flupyradifurone and 6-chloronicotinic acid. The validation results proved that the method was selective, accurate and precise with acceptable linearity. The recovery ranged from 34.1–37.9% for flupyradifurone, and 30.5–47.3% for 6-chloronicotinic acid. A 58-year-old man died on the road bench and flupyradifurone was detected in his stomach contents. The validated method was applied to his heart blood and peripheral blood. The concentrations of flypyradifurone and 6-chloronicotinic acid were 159.8 mg/L and 1.0 mg/L in heart blood and 129.8 mg/L and 1.3 mg/L in peripheral, respectively. This is the first report to identify and quantify flupyradifurone and its metabolite 6-chloronicotinic acid from the fatal case of flupyradifurone intoxication. This developed LC-MS/MS method and analytical results will be very useful for identifying the cause of death in forensic toxicology.

Effect of decontamination and processing on insecticide residues in grape (Muscat Hamburg).

Field and laboratory experiments were conducted to study the effect of simple decontamination methods and processing on imidacloprid, dimethoate, and emamectin benzoate residues in grapes and their processed products by liquid chromatography-mass spectrometry. Among the decontamination methods evaluated, washing with NaCl (2%) solution was effective for reducing imidacloprid (77.55%), dimethoate (83.27%), and emamectin benzoate (77.28%) residues in mature grapes. No metabolites (omethoate and 6-chloronicotinic acid) were detected in both decontamination and processing studies. The grapes were processed into various products, including fresh juice, squash, and raisin, following the standard effective steps for each product. Washing with NaCl (2%) solution for decontamination was included as an additional step in the standard protocol and resulted in substantial removal of surface residues of the selected insecticides. The processing factor calculated was less than one for all the products.

A QuEChERS-HPLC-MS/MS Method with Matrix Matching Calibration Strategy for Determination of Imidacloprid and Its Metabolites in Procambarus clarkii (Crayfish) Tissues.

We developed a method for determination of imidacloprid and its metabolites 5-hydroxy imidacloprid, olefin imidacloprid, imidacloprid urea and 6-chloronicotinic acid in Procambarus clarkii (crayfish) tissues using quick, easy, cheap, effective, rugged, and safe (QuEChERS) and high-performance liquid chromatography-triple quadrupole mass spectrometry. Samples (plasma, cephalothorax, hepatopancrea, gill, intestine, and muscle) were extracted with acetonitrile containing 0.1% acetic acid and cleaned up using a neutral alumina column containing a primary secondary amine. The prepared samples were separated using reverse phase chromatography and scanned in the positive and negative ion multiple reaction-monitoring modes. Under the optimum experimental conditions, spiked recoveries for these compounds in P. clarkii samples ranged from 80.6 to 112.7% with relative standard deviations of 4.2 to 12.6%. The limits of detection were 0.02–0.5 μg·L−1, the limits of quantification were 0.05–2.0 μg·L−1 and the method of quantification was 0.05–2.0 μg·kg−1. The method is rapid, simple, sensitive and suitable for rapid determination and analysis of imidacloprid and its metabolites in P. clarkii tissues.

Simultaneous determination of acetamiprid and 6-chloronicotinic acid in environmental samples by using ion chromatography hyphenated to online photoinduced fluorescence detector.

This study aims to introduce a simple, sensitive, and cost-effective method for the simultaneous determination of acetamiprid and its main metabolite 6-chloronicotinic acid in environmental samples by using a nonsuppressed ion chromatography hyphenated with an online postcolumn photoinduced fluorescence detection system. The fluorescence detector wavelengths λex /λem =257/382nm was set for up to 6.0min for acetamiprid, while λex /λem =231/370nm programmed for 6-chloronicotinic acid for the rest of the analysis time. Both samples were treated by applying miniaturized quick, easy, cheap, effective, rugged, and safe method before the separation of analytes on an IonPac® AS11-HC column by pumping 40mM NaOH having minuscule content of acetonitrile (5%, v/v) as an eluent. Both intrinsically nonfluorescent analytes were turned-on by online postcolumn photoinduced derivatization, avoiding the need for complex chemical derivatization or addition of a postcolumn extra pump. The developed method was appraised for the analysis of environmental samples, exhibiting excellent linearity (0.050-10μg/mL) with a correlation coefficient greater than 0.9993 for both analytes. Whereas, obtained limit of detection (0.025-0.0072μg/mL), recoveries (98.02-116.00%), and inter- and intraday precision (≤3.02 %) were satisfactory for both compounds in environmental samples.

Micellar electrokinetic chromatography as efficient alternative for the multiresidue determination of seven neonicotinoids and 6-chloronicotinic acid in environmental samples.

A simple, sensitive, and efficient method has been developed for the determination of the seven neonicotinoid insecticides commercially available (imidacloprid, thiacloprid, clothianidin, thiamethoxam, acetamiprid, nitenpyram, and dinotefuran) and the main metabolite 6-chloronicotinic acid. Micellar electrokinetic chromatography (MEKC) mode was applied, using 48.5 cm of total length capillary (50 μm i.d.) with an extended light-path capillary (150 μm). The running electrolyte consisted of 25 mM sodium tetraborate buffer (pH 9.2) containing 120 mM of sodium dodecyl sulfate and 15% of methanol (v/v). A voltage of 27 kV and a temperature of 25 °C were applied. Samples dissolved in deionized water were hydrodynamically injected at 50 mbar for 12 s, achieving the analysis in less than 12 min. Diode array detection (DAD) was performed at 220, 254, and 270 nm, depending on the analyte. Two different methodologies as sample treatments were developed; for water samples, solid-phase extraction was checked using different cartridges (C18, Oasis® HLB, Oasis® HLB Prime, and Strata-X), being the best option Oasis® HLB for preconcentration and cleanup. In the case of soil samples, a simple solid-liquid extraction was applied using a mixture of 1:3 (v/v) acetonitrile/dichloromethane. Satisfactory linearity, trueness, and precision were achieved, with detection limits in the range of 0.1-0.4 μg L-1 for river water and 1.0-2.9 μg kg-1 for soil samples. Recoveries in the range of 80-107% for all of the assayed neonicotinoids in water samples of different origin and 73-92% for soil samples were achieved.

Persistence and processing effects in reduction of residues of β-cyfluthrin + imidacloprid and its metabolite in hot pepper

ABSTRACT Now a days, farmers prefer to use Premix Formulations instead of single pesticide for the control of insects and pests. Large number of premix formulations are available in the market, Solomom OD (β-cyfluthrin 90 + imidacloprid 210) is the preferred one in hot pepper. Thus, the present research was done to monitor the leftover and effect of household processing in reduction of premix formulation with its toxic metabolites in hot pepper. Quantification of leftovers in hot pepper fruits was done by using two analytical instruments viz., gas chromatography-tandem mass spectrometry (GC-MSMS) in SCAN/MRM mode with a triple Quadrupole analyser and high-performance liquid chromatography (HPLC) using diode array detector. The limit of quantification (LOQ) for β-cyfluthrin was 0.05 mg kg−1, and for imidacloprid and its metabolite 6-chloronicotinic acid (6-CNA) was 0.01 mg kg−1, respectively. Based on Maximum Residue Limit (MRL) value by Food Safety and Standard Authority of India (FSSAI), the safe waiting period suggested was 3rd day for β-cyfluthrin and 1st day for imidacloprid. Residues of β-cyfluthrin and imidacloprid were persisted up to 7 days in proposed dose (PD) and 10 days in double the proposed dose (DPD) after final spray. No residues of 6-CNA were detected in hot pepper at any stage. Frying after washing was found effective in decreasing the residues when compared to washing alone with plain water. Imidacloprid shows more per cent reduction (87.75–91.49%) in frying after washing when compared to β-cyfluthrin (76.29–84.01%). Red hot pepper and soil collected at 30 days (harvest time) after final spray were found free from pesticide contamination at all test doses.

Urinary monitoring of neonicotinoid imidacloprid exposure to pesticide applicators

Neonicotinoid pesticides have recently drawn attention worldwide owing to their potential adverse effects on non-target organisms and ecosystems. Exposure to imidacloprid, the most widely used neonicotinoid insecticide, is of particular concern among rural populations because of its ubiquitous use in agriculture. Hence, biological monitoring of urinary imidacloprid and its major metabolite 6-chloronicotinic acid (6-CNA) was performed using Polar Enhanced Polymer solid-phase extraction by LC-MS/MS with mean recoveries of 78.3–109.8% and limits of quantitation at 0.029–0.038 ng/mL. Imidacloprid was detected in 100% of urine samples from rural applicators at concentrations of 0.21–8.91 ng/mL (0.06–9.60 μg/g creatinine) and 0.11–24.58 ng/mL (0.66–57.40 μg/g creatinine) before and after pesticide application, respectively. Significant increase in urine concentration (3.52- to 3.77-fold) of imidacloprid and 6-CNA was observed after local imidacloprid field application (p ≤ 0.001). The estimated absorbed daily dose (ADD) for imidacloprid was 0.52–248.05 μg/kg/d, indicating that attention should be paid to potential health risks for applicators because of increased imidacloprid exposure at level of significance (p < 0.05). This study is the first to report ADD estimation for imidacloprid, thereby providing an important reference for further human health risk evaluation.

Determination of nitenpyram and 6-chloronicotinic acid in environmental samples by ion chromatography coupled with online photochemically induced fluorescence detector.

A simple, cost-effective, sensitive, and quick method for the determination of nitenpyram and its metabolite 6-chloronicotinic acid in environmental samples was developed by coupling an ion chromatograph with a fluorescence detector and a post-column photochemical reactor. This developed analytical method involved a rapid sample extraction by modified and miniaturized quick, easy, cheap, effective, rugged, and safe method followed by isocratic ion chromatographic separation of nitenpyram and 6-chloronicotinic acid into an IonPac™ AS11-HC column protected by IonPac™ AG11A guard column by running 30mM NaOH + 10% acetonitrile mobile phase. A homemade post-column photochemical reactor was also integrated with the ion chromatographic system for online transformation of both analytes into their respective highly fluorescent photoproduct in basic media without using an extra pump. The developed method was validated by following SANTE/11945/2015 guidelines on analytical quality control and validation procedures. The method showed a good linear response (r>0.999), improved limit of detection (0.101-0.132μg/L), minimum or no matrix effect, excellent recoveries (90.2-100.10%) and relative standard deviations were found to be ≤6.50%.

Part-per-trillion LC-MS/MS determination of neonicotinoids in small volumes of songbird plasma

Neonicotinoids are the most widely used class of insecticides in the world, and there are increasing concerns about their effects on non-target organisms. Analytical methods to diagnose exposure to neonicotinoids in wildlife are still very limited, particularly for small animals such as songbirds. Blood can be used as a non-lethal sampling matrix, but the sample volume is limited by body size. Neonicotinoids have a low bioaccumulation potential and are rapidly metabolized, therefore, sensitive assays are critically needed to reliably detect their residues in blood samples. We developed an efficient LC-MS/MS method at a part-per-trillion (pg/ml) level to measure eight neonicotinoid related insecticides (acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, nitenpyram, thiacloprid and thiamethoxam) plus one metabolite (6-chloronicotinic acid) in small volumes (50 μL) of avian plasma. The average recovery of target compounds ranged from 95.7 to 101.3%, and relative standard deviations were between 0.82 and 2.13%. We applied the method to screen blood samples from 36 seed-eating songbirds (white-crowned sparrows; Zonotrichia leucophrys) at capture, and detected imidacloprid in 78% (28 of 36), thiamethoxam in 22% (8 of 36), thiacloprid in 11% (4 of 36), and acetamiprid in 11% (4 of 36) of wild-caught sparrows. 6 h after capture, birds were orally dosed with 0 (control), 1.2 or 3.9 mg of imidacloprid/kg bw, test results using this method indicated that plasma imidacloprid was significantly elevated (low 26-times, high 316-times) in exposed groups. This is the first study to confirm neonicotinoid exposure in small free-living songbirds through non-lethal blood sampling, and to demonstrate that environmentally realistic doses significantly elevate circulating imidacloprid concentrations. This sensitive method could be applied to characterize exposure to neonicotinoids in free-living wildlife and in toxicological studies.

Long-term exposure of rabbits to imidaclorpid as quantified in blood induces genotoxic effect

The present in-vivo study focuses on the genotoxic effect of the neonicotinoid pesticide imidacloprid (IMI) in rabbits. The purpose of the study was to establish a possible relationship between exposure to the pesticide (dose and duration) and genotoxicity. Furthermore, an analytical method for the simultaneous determination of IMI and its major metabolite 6-chloronicotinic acid (6-ClNA) in blood was developed and validated. The isolation of the two analytes from blood was performed by liquid–liquid extraction with dichloromethane. Analysis was performed by Liquid Chromatography – Atmospheric Pressure Chemical Ionization – Mass Spectrometry (LC-APCI-MS). The method was applied on the determination of IMI and 6-ClNA in serum samples obtained from rabbits fed with the insecticide at two low doses. Furthermore, parameters of genotoxicity and cytotoxicity were evaluated by measuring binucleated cells with micronuclei (BNMN), micronuclei (MN) and the Cytokinesis Block Proliferation Index (CBPI), in lymphocytes of exposed rabbits. The results revealed a genotoxic effect of IMI for both exposed groups. There were statistically significant differences in the frequencies of BNMN and MN between control and exposed groups but there was no dose-dependence, neither time-dependence of the genotoxic effect for the administered doses. This is the first time that long term exposure to IMI in rabbits was studied for the determination of its genotoxic effect. The genotoxic effect of IMI as it is depicted by the current study is in accordance with previous studies.

A green HPLC technique with a 100% water mobile phase for detecting imidacloprid and its metabolite 6-chloronicotinic acid

Article history: Received July 21, 2015 Received in revised form August 29, 2015 Accepted 19 September 2015 Available online 20 September 2015 This paper describes a harmless HPLC technique for detecting imidacloprid (ICP) and its metabolite, 6-chloronicotinic acid (6CA), using an isocratic 100 % water mobile phase. Chromatographic separations were performed a Daisopak® SP-200-3-C1-P with water mobile phase and a photodiode-array detector. The total run time was < 6 min. The system suitability was well within the international acceptance criteria. The detection limits were 0.018 μg/ml for ICP and 0.005 μg/ml for 6CA, respectively. A harmless HPLC method for simultaneous detecting ICP and 6CA was developed and may be further applied to the quantification in animal-derived foods. © 2015Growing Science Ltd. All rights reserved.

Persistence and Metabolism of Imidacloprid After Seed Treatment in Cotton Field Soil

A field study was carried out to determine the persistence and metabolism of imidacloprid in soil following its seed treatment @ 3.5 g and 14 g a.i. kg−1 of seed. Soil samples were collected at different time intervals from 7–90 days after application and the residues of imidacloprid and its metabolites (6-chloronicotinic acid, imidacloprid-nitrogunidine, olefin, nitrosimine, urea and 5-hydroxy) were quantified by high-performance liquid chromatography. The total imidacloprid residues in soil were mainly constituted by the parent compound followed by olefin and nitrosimine. The limit of quantification for the analysis of imidacloprid and its metabolites was worked out to be 0.01 mg kg−1. The maximum residues of total imidacloprid in soil samples collected 7 days after seed treatment were found to be 1.59 and 3.39 mg kg−1for the two dosages, rspectively. These residues could not be detected after 60 days for both the dosages. Nitrosamine metabolite was found to be the maximum followed by olefin. The half-life values (t 1/2) of total imidacloprid were calculated to be 23.89 and 26.65 days, respectively, when applied at recommended dose and four times the recommended dose, respectively.

The Neonicotinoid Insecticide Imidacloprid: A Male Reproductive System Toxicity Inducer-Human and Experimental Study

Objective: This study was undertaken to explore relationships between level of imidacloprid in the serum and semen quality among men farmers in addition to investigating histopathological findings in treated mature male rats. Methods and results: Our research entailed two parts; firstly, human part done on farm workers (n=35) with age between (Mean ± SD 34.3±6.4) and healthy volunteers (n=25) their ages were (35.6±8.2) years old asked to provide semen and blood samples. A significant negative correlation between sperm concentration, motility, with serum and seminal Imidacloprid (IMI), its main metabolite 6-chloronicotinic acid (6- CINA) and cotinine , was identified in farmers (r= − 0.489; p<0.05). Second part of research was done on adult male rats that had been divided into a total of five groups 10 each. Two groups served as control one as negative and the other as positive. The other three experimental groups were given 45, 90 and 450 mg/kg body weight Imidacloprid in corn orally by a gavage process for fifteen days respectively. There was a significant difference in luteinizing hormone (LH), follicular stimulating hormone (FSH), testestrone (tes), Estradiol 2 (E2), prolactin and semen quality in IMI treated rats when compared to control groups. Vacuolar degeneration of germinal epithelium and loss of spermatids, seminiferous tubules suggesting inhibition of spermatogenesis was recorded in IMI treated rats. Conclusion: Toxic effects to male reproductive system can be considered as an outcome of IMI exposure and infertility problems can be expected in chronically exposed subjects.

Dissipation kinetics and effect of processing on imidacloprid and its metabolites in cardamom (Elettaria cardamomum Maton).

Dissipation behaviour of the chloronicotinyl insecticide, imidacloprid (Tatamida 17.8 % SL), in fresh and cured cardamom capsules was studied following application at doses 20 and 40 g a.i. ha(-1) in a cardamom plantation of Indian Cardamom Hills (ICH), Idukki, Kerala, India. A single-laboratory ultra performance liquid chromatography mass spectrometry (UPLC-MS/MS) method was developed and validated for the estimation of imidacloprid and its six metabolites (5-hydroxy, olefin, guanidine, urea, 6-chloronicotinic acid and nitrosimine) in fresh and cured cardamom. At the lower dose, the initial deposits of total imidacloprid residues were 1.91 and 7.23 μg g(-1), respectively, in fresh and cured cardamom. At the higher dose, the initial residues were 3.94 and 14.72 μg g(-1), respectively, in fresh and cured capsules. The residues dissipated below the quantitation level of 0.01 μg g(-1) after 21 and 28 days at lower dose and after 28 days for both at higher dose. The half-lives of imidacloprid in fresh and cured cardamom were 4.02 and 3.63 days, respectively, at lower dose and 3.61 days for both at higher dose. The waiting periods of imidacloprid on fresh and cured cardamom at lower and higher doses were 21.40, 27.10, 23.85 and 30.70 days, respectively. The mean processing factor of imidacloprid was 3.96 at 20 g a.i. ha(-1). Amongst metabolites of imidacloprid, urea had maximum residues in fresh and cured cardamom followed by 5-hydroxy and guanidine. Other metabolites such as 6-chloronicotinic acid, olefin and nitrosimine were not detected either in fresh or cured cardamom.

Winery vermicomposts to control the leaching of diuron, imidacloprid and their metabolites: Role of dissolved organic carbon content

Soil organic amendment addition is an effective practice in Mediterranean areas due to its associated high agricultural benefits and its potential to reduce the pesticide impact on water resources. However, their metabolites have received scarce attention, even when they may pose more risk than their parent compounds. Two winery vermicomposts obtained from spent grape marc (V1) and the mixture vine shoot-biosolid vinasses (V2) have been investigated as low cost organic amendments to minimize the leaching of diuron, imidacloprid and their metabolites in columns packed with a sandy loam (S1) and a silty-clay loam soil (S2) under steady state flow conditions. In the unamended soil columns, leached amounts of diuron were 75% and 53% in S1 and S2, respectively. Its metabolites (3-(3,4-dichlorophenyl)-1-methylurea, DPMU; and 3,4-dichlorophenylurea, DPU) percolated less than 35% of the total applied amount. The amount of the metabolite 3,4-dichloroaniline (DCA) was 2% and 30% for S1 and S2, respectively. Leaching of imidacloprid was 79% and 96% for S1 and S2, respectively, while its metabolite 6-chloronicotinic acid (CNA) was entirely leached. In the vermicompost-amended columns, the leaching of diuron was reduced 2 to 3-fold. DPMU and DPU were also significantly reduced (more than 6-fold). DCA did not appear in any of the leachates of the amended soil columns. Imidacloprid leaching was reduced 1 to 2-folds in the amended columns. The amendments did not affect the transport of CNA. The dissolved organic carbon (DOC) from the vermicomposts did not enhance pesticide transport throughout the soil in any case. This qualitative study presents these vermicomposts as an effective potential low-cost tool in reducing pesticide and metabolite leaching. The next step would be to test them under more realistic conditions.