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Journal of Food Science and Technology Mar 2014In this study, pesticide residues in parsley, lettuce and spinach (120 samples) were analyzed by the application of liquid chromatography-tandem mass spectrometry...
In this study, pesticide residues in parsley, lettuce and spinach (120 samples) were analyzed by the application of liquid chromatography-tandem mass spectrometry (LC-MS/MS). All samples of spinach, parsley or lettuce contained residues of three or more active substances. In parsley, carbendazim (100.0%), dichlorvos (100.0%), fenarimol (40.0%), pendimethalin (95.0%), in lettuce, diazinon (30.0%), dichlorvos (100.0%), pendimethalin (92.5%) phenthoate (12.5%), and in spinach, carbendazim (45.0%), cymoxanil (85.0%), dichlorvos (100.0%) and fenarimol (85.0%) were the significant active compounds. The maximum residue limits were exceeded in 28, 20 and 40 samples of parsley, lettuce and spinach, respectively. The results showed that there was a high occurrence of pesticide residues in parsley, lettuce and spinach samples from Hatay province, in which most of them were prohibited from use in Turkey for these vegetables. The contamination levels of these residues may be considered a serious public health problem according to the maximum residue limits (MRLs) of Turkey and the European Union (EU).
PubMed: 24587520
DOI: 10.1007/s13197-011-0531-9 -
Analytical Sciences : the International... 2011A rapid, specific, and sensitive method for the simultaneous quantitation of organophosphates (fenitrothion (MEP), malathion, and phenthoate (PAP)), glufosinate (GLUF),...
Mix-mode TiO-C18 monolith spin column extraction and GC-MS for the simultaneous assay of organophosphorus compounds and glufosinate, and glyphosate in human serum and urine.
A rapid, specific, and sensitive method for the simultaneous quantitation of organophosphates (fenitrothion (MEP), malathion, and phenthoate (PAP)), glufosinate (GLUF), and glyphosate (GLYP) in human serum and urine by gas chromatography-mass spectrometry (GC-MS) has been validated. All of the targeted compounds together with the internal standard were extracted from the serum and urine using a mix-mode TiO-C(18) monolithic spin column. The recovery of organophosphates from serum and urine ranged from 12.7 to 49.5%. The recovery of GLUF and GLYP from serum and urine ranged from 1.9 to 7.9%. The intra- and inter-accuracy and precision (expressed as relative standard deviation, %RSD) were within 96.7-107.7% and 4.0-13.8%, respectively. The detection and quantitation limits for serum and urine were 0.1 and 0.1 µg/ml, respectively, for organophosphates, 0.1 and 0.5 µg/ml, respectively for GLUF and GLYP. The method had linear calibration curves ranging from 0.1 to 25.0 µg/ml for organophosphates and 0.5-100.0 µg/ml for GLUF, and GLYP. The validated method was successfully applied to a clinical GLYP poisoning case.
Topics: Aminobutyrates; Gas Chromatography-Mass Spectrometry; Glycine; Humans; Organophosphorus Compounds; Polymethacrylic Acids; Sensitivity and Specificity; Titanium; Glyphosate
PubMed: 21985924
DOI: 10.2116/analsci.27.999 -
Journal of Chromatography. A Sep 2010Eight chiral pesticides, which were selected to cover different pesticide species and origins of chirality, were investigated to explore their chiral stability in...
Eight chiral pesticides, which were selected to cover different pesticide species and origins of chirality, were investigated to explore their chiral stability in organic solvents and water. Profenophos, fenamiphos, quizalofop-ethyl, dichlorprop-methyl (DCPP-methyl) and acetochlor were showed stable under all test conditions. However, significant racemization was observed for malathion, phenthoate and fenpropathrin in methanol, ethanol and water, but not in n-hexane, isopropanol, acetone or methylene chloride. The kinetic parameters (rate constant k and half-life T(1/2)) of the abiotic racemization were calculated through a mathematical model of the first-order reaction. Furthermore, the extent of racemization varied among the solvents and was also affected by temperature dependence. The racemization of malathion, phenthoate and fenpropathrin in water was documented to be pH-dependent and took place more rapidly at pH 7.0 than at pH 5.8. The observed racemization was deduced to occur via a proton exchange process at the chiral center, and the relationship between the abiotic racemization and pesticide structure was further explored. Findings from this study are useful for better understanding enantioselectivity of chiral pesticides in environment and also for proper analysis, formulating or handling of enantiopure products.
Topics: 2,4-Dichlorophenoxyacetic Acid; Chromatography, High Pressure Liquid; Drug Stability; Ethanol; Hydrogen-Ion Concentration; Kinetics; Methanol; Organothiophosphorus Compounds; Pesticides; Propionates; Quinoxalines; Solvents; Stereoisomerism; Water
PubMed: 20688331
DOI: 10.1016/j.chroma.2010.07.016 -
Journal of Chromatographic Science Mar 2010Determination of 23 organophosphorous pesticides (sulfotep, phorate, demeton, diazinon, disulfoton, kitazzin.P, chlorpyrifos-methyl, methyl-parathion, ronnel,...
Determination of 23 organophosphorous pesticides (sulfotep, phorate, demeton, diazinon, disulfoton, kitazzin.P, chlorpyrifos-methyl, methyl-parathion, ronnel, fenitrothion, malathion, chlorpyrifos, fenthion, parathion, bromophos, isofenphos-methyl, phenthoate, quinalphos, ethion, triazophos, carbophenothion, pirimiphos-methyl, and pirimiphos-ethyl) in water using solid-phase microextraction (SPME) with gas chromatography-mass spectrometry detection (GC-MS) was investigated. The influence of various parameters on pesticides extraction efficiency by SPME was thoroughly studied. For quantitation in the selective ion monitoring (SIM) mode, the linear range of most compounds was found to be between 0.05-10 microg/L, and the detection limits were between 0.7-50 ng/L. To validate matrix effects for surface water, the recoveries were calculated between 71-104%. SPME in combination with GC-MS is a sensitive and effective method for the determination of organophosphorous pesticides (OPPs) in water samples.
Topics: Gas Chromatography-Mass Spectrometry; Limit of Detection; Organothiophosphorus Compounds; Pesticides; Rivers; Solid Phase Microextraction; Water; Water Pollutants, Chemical
PubMed: 20223083
DOI: 10.1093/chromsci/48.3.183 -
Journal of Environmental Science and... Aug 2009The goal of this work was to study the ability of 18 pesticides to inhibit selective model activities for all major xenobiotic-metabolizing enzymes, namely CYP1A1/2,...
The goal of this work was to study the ability of 18 pesticides to inhibit selective model activities for all major xenobiotic-metabolizing enzymes, namely CYP1A1/2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4. Generally organophosphorus insecticides were the most potent and extensive inhibitors, especially towards CYP1A1/2 (IC(50) values of chlorpyrifos, fenitrothion and profenofos approximately 3 micro M), CYP2B6 (IC(50) values of chlorpyrifos and fenitrothion 2.5 micro M), CYP2C8 (fenitrothion 4.3 micro M), CYP2C9 (fenitrothion and malathion 4.8 and 2.5 micro M, respectively), CYP2D6 (chlorpyrifos and phenthoate approximately 3 micro M) and CYP3A4 (chlorpyrifos, fenitrothion and phenthoate 3-4 micro M). Otherwise there were quite considerable differences in potency and extent of inhibition between different organophosphates. Pyrethroids were in general very weak or inactive. Deltamethrin and fenvalerate were potent inhibitors of CYP2D6 (IC(50) values of approximately 3 micro M) while lambda-cyhalothrin potently inhibited both CYP2D6 and CYP3A4-mediated activities (IC(50)'s about 3-4 micro M). Some pesticides caused relatively potent inhibitions sporadically (carbendazim, CYP2D6, IC(50) = 12 micro M; atrazine, CYP3A4, IC(50) = 2.8 micro M; glyphosate, CYP2C9, IC(50) = 3.7 micro M; hexaflumuron, IC(50) = 6.0 micro M). With the exceptions of alpha-cypermethrin, cypermethrin, isoproturon, carbaryl and abamectin, most pesticides inhibited relatively potently at least one CYP-selective activity, which may have relevance for potential interactions in occupational exposures and for further studies on the CYP-associated metabolism of respective pesticides.
Topics: Aryl Hydrocarbon Hydroxylases; Cytochrome P-450 CYP2C8; Cytochrome P-450 CYP2C9; Cytochrome P-450 CYP2D6 Inhibitors; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Humans; Inhibitory Concentration 50; Microsomes, Liver; Pesticides
PubMed: 20183062
DOI: 10.1080/03601230902997766 -
The Korean Journal of Internal Medicine Dec 2009Organophosphate poisoning has a high mortality rate. Recently, differences among organophosphorus insecticides in human self-poisoning were reported. This study...
BACKGROUND/AIMS
Organophosphate poisoning has a high mortality rate. Recently, differences among organophosphorus insecticides in human self-poisoning were reported. This study investigated the prognostic risk factors and the mortality of different organophosphates following acute organophosphate poisoning.
METHODS
This retrospective study included 68 patients with acute organophosphate poisoning. We investigated patient survival according to initial parameters, including the initial Acute Physiology and Chronic Health Evaluation (APACHE) II score, serum cholinesterase level, and hemoperfusion and evaluated the mortality according to organophosphate types.
RESULTS
Thirteen of the 68 patients died. The agents responsible for mortality were different. The APACHE II score was a significant predictor of mortality (odds ratio [OR], 1.194; p<0.01; 95% confidence interval [CI], 1.089 to 1.309) and respiratory failure (OR, 1.273; p<0.01; 95% CI, 1.122 to 1.444). The mortality was 0% for dichlorvos, malathion, chlorpyrifos and profenofos. However, other organophosphates showed different mortality (16.7% for O-ethyl-O-4-nitrophenyl phenylphosphonothioate, 25% for phenthoate, 37.5% for phosphamidon, 50% for methidathion). The usefulness of hemoperfusion appears to be limited.
CONCLUSIONS
The initial APACHE II score is a useful prognostic indicator, and different organophosphates have different mortality.
Topics: APACHE; Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Cholinesterases; Female; Humans; Male; Middle Aged; Organophosphate Poisoning; Poisoning; Prognosis; Retrospective Studies
PubMed: 19949736
DOI: 10.3904/kjim.2009.24.4.362 -
Analytica Chimica Acta May 2008A general and broad class-specific enzyme-linked immunosorbent assay was developed for the O,O-dimethyl organophosphorus pesticides, including malathion, dimethoate,...
A general and broad class-specific enzyme-linked immunosorbent assay was developed for the O,O-dimethyl organophosphorus pesticides, including malathion, dimethoate, phenthoate, phosmet, methidathion, fenitrothion, methyl parathion and fenthion. Three haptens with different spacer-arms were synthesized. The haptens were conjugated to bovine serum albumin (BSA) for immunogens and to ovalbumin (OVA) for coating antigens. Rabbits were immunized with the immunogens and six polyclonal antisera were produced and screened against each of the coating antigens using competitive indirect enzyme-linked immunosorbent assay for selecting the proper antiserum. The effect of hapten heterology on immunoassay sensitivity was also studied. The antibody-antigen combination with the most selectivity for malathion was further optimized and tested for tolerance to co-solvent, pH and ionic strength changes. The IC(50) values, under optimum conditions, were estimated to be 30.1microgL(-1)for malathion, 28.9microgL(-1) for dimethoate, 88.3microgL(-1) for phenthoate, 159.7microgL(-1) for phosmet, 191.7microgL(-1) for methidathion, 324.0microgL(-1) for fenitrothion, 483.9microgL(-1) for methyl parathion, and 788.9microgL(-1) for fenthion. Recoveries of malathion, dimethoate, phenthoate, phosmet and methidathion from fortified Chinese cabbage samples ranged between 77.1% and 104.7%. This assay can be used in monitoring studies for the multi-residue determination of O,O-dimethyl organophosphorus pesticides.
Topics: Animals; Enzyme-Linked Immunosorbent Assay; Haptens; Humans; Organophosphorus Compounds; Pesticides; Rabbits; Sensitivity and Specificity
PubMed: 18442523
DOI: 10.1016/j.aca.2008.03.050 -
Food Additives & Contaminants. Part A,... Jan 2008An approach based on solid-phase microextraction-liquid chromatography-mass spectrometry (SPME-LC-MS) has been developed for determining 12 insecticides (bromophos...
An approach based on solid-phase microextraction-liquid chromatography-mass spectrometry (SPME-LC-MS) has been developed for determining 12 insecticides (bromophos ethyl, chlorpyrifos methyl, chlorpyrifos ethyl, diazinon, fenoxycarb, fonofos, phenthoate, phosalone, pirimiphos methyl, profenofos, pyrazophos, and temephos) in honey. The influence of several parameters on the efficiency of the SPME was systematically investigated. Under optimal conditions, the procedure provided excellent linearity (>0.990), detection and quantification limits (between 0.001 and 0.1 microg g(-1) and between 0.005 and 0.5 microg g(-1), respectively), and precision (<19% at the quantification limits and from 6 to 14% at ten times higher concentrations). However, recoveries were not so good, ranging from 19 to 92%. Honey samples were found that were contaminated with bromophos ethyl, diazinon, fonofos, pirimiphos ethyl, pyrazophos, and temephos at estimated concentrations from 6.2 +/- 1.2 to 19 +/- 3 ng g(-1).
Topics: Carbamates; Chromatography, Liquid; Honey; Insecticides; Linear Models; Mass Spectrometry; Maximum Allowable Concentration; Organophosphorus Compounds; Pesticide Residues; Solid Phase Microextraction
PubMed: 17852391
DOI: 10.1080/02652030701424529 -
Journal of Chromatography. A Sep 2007A reliable multi-residue method which was based on solid-phase extraction (SPE) with multi-walled carbon nanotubes (MWCNTs) as adsorbent was developed for determination...
A reliable multi-residue method which was based on solid-phase extraction (SPE) with multi-walled carbon nanotubes (MWCNTs) as adsorbent was developed for determination and quantitation of 12 pesticides (carbofuran, iprobenfos, parathion-methyl, prometryn, fenitrothion, parathion-ethyl, isocarbofos, phenthoate, methidathion, endrin, ethion, methoxychlor) in surface water by gas chromatography-mass spectrometry (GC-MS). Parameters that might influence the extraction efficiency such as the eluent volume, the sample flow rate and the sample loading volume were optimized. The experimental results showed the excellent linearity of 12 pesticides (R(2)>0.99) over the range of 0.04-4 microg L(-1), and the precisions (RSD) were 3.1-15.1% under the optimal conditions. The detection limits of proposed method could reach 0.01-0.03 microg L(-1) based on the ratio of chromatographic signal to base line noise (S/N=3). Good recoveries achieved with spiked water samples were in the range of 82.0-103.7%. The results indicated that MWCNTs have good adsorbability to the 12 pesticides tested in this study. With less cost, less analytical time and less solvent-consuming, the developed multi-residue method could be used to determine multi-class pesticides in water simultaneously.
Topics: Gas Chromatography-Mass Spectrometry; Nanotubes, Carbon; Pesticide Residues; Sensitivity and Specificity; Solid Phase Extraction; Water; Water Pollutants, Chemical
PubMed: 17697685
DOI: 10.1016/j.chroma.2007.07.061 -
Pest Management Science Jul 2007Efficient chemical control is achieved when insecticides are active against insect pests and safe to natural enemies. In this study, the toxicity of 17 insecticides to...
Efficient chemical control is achieved when insecticides are active against insect pests and safe to natural enemies. In this study, the toxicity of 17 insecticides to the sweetpotato whitefly, Bemisia tabaci (Gennadius), and the selectivity of seven insecticides to natural enemies of this insect pest were evaluated. To determine the insecticide toxicity, B. tabaci adults were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion, methamidophos, bifenthrin, cypermethrin, deltamethrin, esfenvalerate, fenitrothion, fenpropathrin, fenthion, phenthoate, permethrin and trichlorphon at 50 and 100% of the field rate (FR), and to water (untreated control). To determine the insecticide selectivity, adults of Encarsia sp., Acanthinus sp., Discodon sp. and Lasiochilus sp. were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion and methamidophos at 50 and 100% FR, and to water. Groups of each insect species were exposed to kale leaves preimmersed in each treatment under laboratory conditions. Mortality of exposed individuals was recorded 24 h after treatment. Cartap and imidacloprid at 50 and 100% FR and abamectin and acetamiprid at 100% FR showed insecticidal activity to B. tabaci adults. Abamectin at 50 and 100% FR was the least insecticidal compound to the natural enemies Acanthinus sp., Discodon sp. and Lasiochilus sp. The present results suggest that abamectin at 100% FR may decrease B. tabaci field populations but can still be harmless to predators. Implications of these results within an integrated pest management context are discussed.
Topics: Animals; Brassica; Coleoptera; Food Chain; Hemiptera; Insecticides; Pest Control, Biological; Wasps
PubMed: 17523144
DOI: 10.1002/ps.1393