-
The Science of the Total Environment Dec 2017Pesticides are needed to maintain high production in the vineyard area of La Rioja (Spain), and monitoring their spatial distribution is a priority for preserving the...
Pesticides are needed to maintain high production in the vineyard area of La Rioja (Spain), and monitoring their spatial distribution is a priority for preserving the quality of natural resources. Accordingly, the purpose of this work was to conduct a study to evaluate the presence and seasonal distribution of herbicide and insecticide residues in ground and surface waters in this region. The monitoring network comprised 12 surface waters and 78 groundwaters, covering the three subareas (63,593ha) into which the vineyard region is divided. The quality of natural waters was examined through the analysis of twenty-two herbicides, eight of their main degradation products, and eight insecticides. Pesticides were extracted by solid-phase extraction, and analysed by gas chromatography-mass spectrometry or by liquid-chromatography-mass spectrometry. The results reveal the presence of most of the herbicides and insecticides included in the study in one or more of the samples collected during the four campaigns. The herbicide terbuthylazine and its metabolite desethylterbuthylazine were the compounds more frequently detected (present in >65% of the samples across all the campaigns). Other compounds detected in >50% of the samples in one sampling campaign were the herbicides fluometuron, metolachlor, alachlor and ethofumesate. Insecticides were present in a small number of samples, with only pirimicarb being detected in >25% of the samples in March and June campaigns. The results reveal that the sum of compounds detected (mainly herbicides) was higher than 0.5μgL in >50% of the samples, especially in the campaigns with the highest application of these compounds. A possible recovery of the quality of the waters was detected outside the periods of crop cultivation, although more monitoring programmes are needed to confirm this trend with a view to preventing and/or maintaining the sustainability of natural resources.
Topics: Environmental Monitoring; Farms; Herbicides; Insecticides; Seasons; Spain; Water Pollutants, Chemical; Water Resources
PubMed: 28750227
DOI: 10.1016/j.scitotenv.2017.07.113 -
Pest Management Science Apr 2015The function of acetylcholinesterase (AChE) is to terminate synaptic transmission by hydrolysing the neurotransmitter acetylcholine (ACh) in the synaptic cleft, and thus...
BACKGROUD
The function of acetylcholinesterase (AChE) is to terminate synaptic transmission by hydrolysing the neurotransmitter acetylcholine (ACh) in the synaptic cleft, and thus it is an effective target for organophosphate (OP) and carbamate (CB) insecticides.
RESULTS
The transcript levels of the four Ace genes were dramatically suppressed by injection of their respective dsRNA in Rhopalosiphum padi and Sitobion avenae. However, the AChE activity changes in the Ace1 knockdown aphids were consistent with the significant transcript level changes of Ace1 genes in these aphids, but not for Ace2. Bioassay results indicated that the suppression of RpAce1 increased its susceptibilities to pirimicarb and malathion, and SaAce1 silencing also increased susceptibility to pirimicarb in S. avenae, whereas the knockdowns of RpAce2 and SaAce2 had a slight effect on their susceptibilities. The knockdown of Ace1 genes also caused significant reductions in fecundity in the aphids of their parental generation.
CONCLUSIONS
These results suggest that AChE1 is a predominant cholinergic enzyme and is the target of anticholinesterase insecticides in both R. padi and S. avenae. It also plays a non-cholinergic role in fecundity of these aphids. AChE2 may also be important for the toxicological function, although its importance appeared to be lower than that of AChE1.
Topics: Acetylcholinesterase; Animals; Aphids; Carbamates; Cholinesterase Inhibitors; Gene Silencing; Insect Proteins; Insecticides; Malathion; Pyrimidines; Species Specificity
PubMed: 24729410
DOI: 10.1002/ps.3800 -
EXCLI Journal 2015A dramatic increase in pesticide usage in agriculture highlights the need for on-site monitoring for public health and safety. Here, a paper-based sensor combined with a...
A dramatic increase in pesticide usage in agriculture highlights the need for on-site monitoring for public health and safety. Here, a paper-based sensor combined with a wet system was developed for the simple and rapid screening of organophosphate (OP) and carbamate (CM) pesticides based on the inhibition of acetylcholinesterase (AChE). The paper-based sensor was designed as a foldable device consisting of a cover and detection sheets pre-prepared with indoxyl acetate and AChE, respectively. The paper-based sensor requires only the incubation of a sample on the test zone for 10 minutes, followed by closing of the foldable sheet to initiate the enzymatic reaction. Importantly, the buffer loading hole was additionally designed on the cover sheet to facilitate the interaction of the coated substrate and the immobilized enzyme. This subsequently facilitates the mixing of indoxyl acetate with AChE, resulting in the improved analytical performance of the sensor. The absence or decrease in blue color produced by the AChE hydrolysis of indoxyl acetate can be observed in the presence of OPs and CMs. Under optimized conditions and using image analysis, the limit of detection (LOD) of carbofuran, dichlorvos, carbaryl, paraoxon, and pirimicarb are 0.003, 0.3, 0.5, 0.6, and 0.6 ppm, respectively. The assay could be applied to determine OP and CM residues in spiked food samples. Visual interpretation of the color signal was clearly observed at the concentration of 5 mg/kg. Furthermore, a self-contained sample pre-concentration approach greatly enhanced the detection sensitivity. The paper-based device developed here is low-cost, requires minimal reagents and is easy to handle. As such, it would be practically useful for pesticide screening by non-professional end-users.
PubMed: 26417364
DOI: 10.17179/excli2014-684 -
Environmental Science and Pollution... May 2021Modern technologies (especially with the help of autonomous measurement and control systems) introduced automatic composters for the disposal of household food waste...
Modern technologies (especially with the help of autonomous measurement and control systems) introduced automatic composters for the disposal of household food waste production. Environmental risks connected with the utilization of these composts can be characterized by the high electrical conductivity caused by a presence of sodium chloride in food. Electrical conductivity influences the ecotoxicity of the composts. The presence of pesticides in composted food also represents an important environmental problem. The following pesticides were found in compost samples from household food waste: 1,3,5-triazine, methyl trithion, bifenthrin, bifenox, carbophenothion, pirimicarb, dioxacarb, desmetryn. Pesticide content in composts varied from 0.3 to 16.3 μg/kg, the average value being 30.4 ± 10.1 μg/kg dry matter. The higher decomposition was found of "modern" pesticides in the composters. The removal of salts can ensure that inhibition will be < 30% while washing with the ratio of 1:3 will result in the inhibition < 5%. However, this way of processing is not effective for other organisms-Poecilia reticulata (mortality 100%) and Daphnia magna (immobilisation 100%) using this procedure as well as washing of the compost in the ratio 3:1.
Topics: Composting; Food; Refuse Disposal; Soil
PubMed: 32705551
DOI: 10.1007/s11356-020-09916-5 -
Food Chemistry Aug 2017This article developed a method to detect two antioxidants (butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT)) and twelve pesticides (dichlorvos,...
This article developed a method to detect two antioxidants (butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT)) and twelve pesticides (dichlorvos, pirimicarb, prothiofos, fenitrothion, ethoprophos, malathion, beta-Cypermethrin, profenofos, diazinon, propoxur, procymidon, captan) in blended oil samples after their extraction simultaneously. The establishment of the method was based on two-step process of screening and optimization experiment design. With a Plackett-Burman (PB) design, significant parameters were found by screening experiment and single factor experiment accompanied by a central composite design (CCD) experiment were used to make important parameters optimal. The coefficients of determination (r) was between 0.9931 and 0.9996 while the limits of quantification (LOQs) and limits of detection (LODs) were found in scope of 0.002-0.04mg·kg and 0.0006-0.0012mg·kg. Recovery values of analytes were above 74%, at the same time the relative standard deviations (RSDs) under 10% at the concentrations ranging from 0.05mg·kg to 0.20mg·kg. To sum up, this method with shorter time and fewer consumption of reagents could be employed in various occasions to detect antioxidants and pesticides.
Topics: Antioxidants; Liquid-Liquid Extraction; Pesticide Residues; Solid Phase Extraction
PubMed: 28372183
DOI: 10.1016/j.foodchem.2017.02.094 -
Food and Chemical Toxicology : An... Jan 2019Dietary supplements are regulated by the U.S. FDA as a subset of foods. Most botanical dietary ingredients do not have pesticide tolerances, resulting in the enforcement...
Dietary supplements are regulated by the U.S. FDA as a subset of foods. Most botanical dietary ingredients do not have pesticide tolerances, resulting in the enforcement of zero tolerance or general maximum residue limits (GMRL), rather than utilizing science-informed tolerances. In the current study, chemical-specific maximum allowable levels (MALs) were derived for 185 pesticides by converting existing, authoritative-body human health effects criteria. MALs were derived for 96% of pesticides using criteria established by the U.S. EPA. If multiple authoritative-bodies had established human health effects criteria, the most scientifically-defensible criteria was selected, taking into consideration both carcinogenic and non-carcinogenic endpoints. Five pesticides (o-phenylphenol, pirimicarb, oxadixyl, tetradifon, o,p'-DDT), lacking criteria established by the U.S. EPA had criteria established by other authoritative-bodies that were utilized in the derivation of MALs. Two pesticides did not have any established human health effects criteria (o,p'-DDD and o,p'-DDE). In total, MALs were derived from existing criteria for over 98% of the pesticides in the present study. Consequently, it is demonstrated that human health effects criteria derived by authoritative-bodies can be effectively utilized to derive chemical-specific, science-informed MALs applicable to all food commodities, including botanical ingredients, thereby, minimizing reliance on precautionary zero tolerance and GMRLs.
Topics: Dietary Supplements; Drug Contamination; Humans; Maximum Allowable Concentration; Pesticide Residues
PubMed: 30468839
DOI: 10.1016/j.fct.2018.11.045 -
Environmental Toxicology and... Jan 2015It is necessary to explore the effect of confidence intervals on the combination index (CI) so that rationally evaluate the toxicological interaction (synergism or...
Application of the combination index integrated with confidence intervals to study the toxicological interactions of antibiotics and pesticides in Vibrio qinghaiensis sp.-Q67.
It is necessary to explore the effect of confidence intervals on the combination index (CI) so that rationally evaluate the toxicological interaction (synergism or antagonism) which is dependent on the concentration ratio, the mixture concentration and the exposure time. To effectively detect the toxicological interaction taking place in mixtures, we combined the CI with the observation-based confidence intervals (OCI) which can characterize the uncertainty in toxicity test and in data fitting. In time scale, the short-term (15min) and long-term (12h) toxicities of three chemicals (imidacloprid (IMI), pirimicarb (PIR) and streptomycin sulfate (STR)) and their binary mixtures on Vibrio qinghaiensis sp.-Q67 were determined by the microplate toxicity analysis (MTA). The mixtures of IMI, PIR and STR have additive actions all but four IMI-PIR rays (R2-R5) at the effect levels above about 30-40% whose long-term toxicological interaction are synergism.
Topics: Anti-Bacterial Agents; Carbamates; Drug Interactions; Imidazoles; Neonicotinoids; Nitro Compounds; Pesticides; Pyrimidines; Streptomycin; Vibrio
PubMed: 25589171
DOI: 10.1016/j.etap.2014.12.013 -
Parasitology Research Dec 2014Varroa destructor is the main concern related to the gradual decline of honeybees. Nowadays, among the various acaricides used in the control of V. destructor, most...
Varroa destructor is the main concern related to the gradual decline of honeybees. Nowadays, among the various acaricides used in the control of V. destructor, most presents increasing resistance. An interesting alternative could be the identification of existent molecules as new acaricides with no effect on honeybee health. We have previously constructed the first 3D model of AChE for honeybee. By analyzing data concerning amino acid mutations implicated in the resistance associated to pesticides, it appears that pirimicarb should be a good candidate for varroacide. To check this hypothesis, we characterized the AChE gene of V. destructor. In the same way, we proposed a 3D model for the AChE of V. destructor. Starting from the definition of these two 3D models of AChE in honeybee and varroa, a comparison between the gorges of the active site highlighted some major differences and particularly different shapes. Following this result, docking studies have shown that pirimicarb adopts two distinct positions with the strongest intermolecular interactions with VdAChE. This result was confirmed with in vitro and in vivo data for which a clear inhibition of VdAChE by pirimicarb at 10 μM (contrary to HbAChE) and a 100% mortality of varroa (dose corresponding to the LD50 (contact) for honeybee divided by a factor 100) were observed. These results demonstrate that primicarb could be a new varroacide candidate and reinforce the high relationships between in silico, in vitro, and in vivo data for the design of new selective pesticides.
Topics: Acaricides; Acetylcholinesterase; Amino Acid Sequence; Animals; Base Sequence; Bees; Carbamates; Cholinesterase Inhibitors; Models, Molecular; Molecular Docking Simulation; Molecular Sequence Data; Pyrimidines; Sequence Alignment; Varroidae
PubMed: 25358237
DOI: 10.1007/s00436-014-4150-z -
Journal of Separation Science Nov 2016Graphene-based pipette tip solid-phase extraction was combined with ultra-high performance liquid chromatography and tandem mass spectrometry for the determination of...
Graphene-based pipette tip solid-phase extraction with ultra-high performance liquid chromatography and tandem mass spectrometry for the analysis of carbamate pesticide residues in fruit juice.
Graphene-based pipette tip solid-phase extraction was combined with ultra-high performance liquid chromatography and tandem mass spectrometry for the determination of carbamate pesticide residues in fruit juice samples. Four milligrams of graphene was used as sorbent material to pack a 1000 μL pipette tip for the extraction of pirimicarb, propoxur, isoprocarb, fenobucarb, and diethofencarb from 3 mL of fruit juice sample. The whole extraction process was finished in 12 min, and the volume of eluent used was only 1.5 mL. Under the optimized conditions, good linear relationship (R > 0.999) and lower limits of detection (0.0022-0.033 ng/mL) were achieved. The recoveries at three spiked levels ranged from 80.90 to 124.60% with relative standard deviations less than 4.88%. Compared with commercially available sorbents including propylsulfonic acid silica, graphitized carbon black, and C , graphene was superior in extraction efficiency. The proposed method is simple, rapid, sensitive, selective, and solvent saving.
Topics: Carbamates; Chromatography, High Pressure Liquid; Fruit and Vegetable Juices; Graphite; Pesticide Residues; Solid Phase Extraction; Tandem Mass Spectrometry
PubMed: 27647795
DOI: 10.1002/jssc.201600498 -
Journal of Chromatography. A Aug 2014In this paper, graphene, a new sorbent material, was synthesized and used for solid-phase extraction (SPE) of the six carbamate pesticides (pirimicarb, baygon, carbaryl,...
Graphene based solid phase extraction combined with ultra high performance liquid chromatography-tandem mass spectrometry for carbamate pesticides analysis in environmental water samples.
In this paper, graphene, a new sorbent material, was synthesized and used for solid-phase extraction (SPE) of the six carbamate pesticides (pirimicarb, baygon, carbaryl, isoprocarb, baycarb and diethofencarb) in environmental water samples. The target analytes can be extracted on the graphene-packed SPE cartridge, and then eluted with acetone. The eluate was collected and dried by high purity nitrogen gas at room temperature. 1mL of 20% (v/v) acetonitrile aqueous solution was used to redissolve the residue. The final sample solution was analyzed by ultra performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) system. Under optimum conditions, good linearity was obtained for the carbamates with correlation coefficient in the range of 0.9992-0.9998. The limits of detection (S/N=3) for the six carbamate pesticides were in the range of 0.5-6.9ngL(-1). Relative standard deviations (RSD) for five replicate determinations were below 5.54%. RSD values for cartridge-to-cartridge precision (n=7) were in the range of 1.27-8.13%. After proper regeneration, the graphene-packed SPE cartridge could be re-used over 100 times for standard solution without significant loss of performance. The enrichment factors for the target analytes were in the range of 34.2-51.7. The established method has been successfully applied to the determination of carbamate pesticide residues in environmental water samples such as river water, well water and lake water.
Topics: Carbamates; Chromatography, High Pressure Liquid; Fresh Water; Graphite; Hydrogen-Ion Concentration; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Pesticide Residues; Solid Phase Extraction; Tandem Mass Spectrometry; Water Pollutants, Chemical
PubMed: 24973804
DOI: 10.1016/j.chroma.2014.05.085