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1.
Foliar applications of synthetic pyrethroids were made to several crops to determine residue levels at various intervals after application. On onions, residues of cypermethrin, permethrin and fenvalerate were negligible > 0.1 mg kg?1, 7 days after application. On lettuce, residues of fenvalerate and permethrin were 0.8 mg kg?1. On celery, residues of fenvalerate did not decline and ranged from 0.12 to 0.25 mg kg?1 during the 14-day period. On green bush-beans, residues of permethrin and cypermethrin did not decline during the 14-day period and ranged from 0.1 to 0.6 mg kg?1. By day 7, residues of cyfluthrin, cypermethrin, deltamethrin, fenvalerate and permethrin on strawberries were less than the acceptable maximum tolerance of 0.1 mg kg?1 with the exception of cypermethrin, applied at the rate of 0.14 kg a.i. ha?1 which gave a residue of 0.14 mg kg?1.  相似文献   

2.
The depletion of zeta‐cypermethrin residues in bovine tissues and milk was studied. Beef cattle were treated three times at 3‐week intervals with 1 ml 10 kg?1 body weight of a 25 g litre?1 or 50 g litre?1 pour‐on formulation (2.5 and 5.0 mg zeta‐cypermethrin kg?1 body weight) or 100 mg kg?1 spray to simulate a likely worst‐case treatment regime. Friesian and Jersey dairy cows were treated once with 2.5 mg zeta‐cypermethrin kg?1 in a pour‐on formulation. Muscle, liver and kidney residue concentrations were generally less than the limit of detection (LOD = 0.01 mg kg?1). Residues in renal‐fat and back‐fat samples from animals treated with 2.5 mg kg?1 all exceeded the limit of quantitation (LOQ = 0.05 mg kg?1), peaking at 10 days after treatment. Only two of five kidney fat samples were above the LOQ after 34 days, but none of the back‐fat samples exceeded the LOQ at 28 days after treatment. Following spray treatments, fat residues were detectable in some animals but were below the LOQ at all sampling intervals. Zeta‐cypermethrin was quantifiable (LOQ = 0.01 mg kg?1) in only one whole‐milk sample from the Friesian cows (0.015 mg kg?1, 2 days after treatment). In whole milk from Jersey cows, the mean concentration of zeta‐cypermethrin peaked 1 day after treatment, at 0.015 mg kg?1, and the highest individual sample concentration was 0.025 mg kg?1 at 3 days after treatment. Residues in milk were not quantifiable beginning 4 days after treatment. The mean concentrations of zeta‐cypermethrin in milk fat from Friesian and Jersey cows peaked two days after treatment at 0.197 mg kg?1 and 0.377 mg kg?1, respectively, and the highest individual sample concentrations were 2 days after treatment at 0.47 mg kg?1 and 0.98 mg kg?1, respectively. © 2001 Society of Chemical Industry  相似文献   

3.
Two radiolabelled forms of racemic [14C]cypermethrin (14C at the benzylic carbon or at C-1 of the cyclopropane ring) were separately administered twice daily to lactating cows in portions of the feed. The amounts dosed were equivalent to 0.2, 5 and 10 μg of cypermethrin per g of feed. The radioactivity eliminated in the milk indicated that the ingestion and elimination of radioactivity were in balance at about day 4 after the start of dosing. Urine and faeces were equally the major routes of elimination, and only a fraction of a percent of the dose appeared in the milk. The residue in the milk was unchanged cypermethrin and was found at a concentration that was proportional to the dose. At the high cypermethrin intake of 10 μg g?1 of diet, the residue in the milk was 0.03 μg g?1. Concentrations of residues in the tissues, measured after 7, 20 or 21 days of treatment, were low and in the order: liver>kidney>renal fat>subcutaneous fat>blood>muscle>brain. The major residue in the liver and kidney of a cow that received 10 μg of cypermethrin per g of diet was N-(3-phenoxybenzoyl)glutamic acid. Other conjugates of 3-phenoxybenzoic acid and of 3-(4-hydroxyphenoxy)benzoic acid (unidentified, with the exception of the glycine conjugate) were also present. The residue in fat (about 0.1 μg g?1 from an intake of 10 μg g?1 of feed) consisted mainly of cypermethrin.  相似文献   

4.
This paper describes the development of methods suitable for the sampling and analysis of the pyrethroid insecticides lambda-cyhalothrin and cypermethrin in natural waters. A solid-phase water-sampling method which avoids the requirement for transport and storage of large volumes of water is described. This method is shown to be capable of extracting trace levels (ng litre?-1) of the title compounds from natural waters with efficiencies of at least 80%. Chromatographic analysis of processed samples by gas chromatography–electron capture detection enables determination of residues at levels of 1–2 ng litre?-1 in water.  相似文献   

5.
Disposition kinetics of cypermethrin and fenvalerate were investigated in lactating black Bengal goats following single dose intravenous administration at 57 and 45 mg kg?1 respectively. The maximum and minimum blood concentrations of cypermethrin were 18.49 (±3.17) and 0.06 (±0.002) μg ml?1, while the corresponding values for fenvalerate were 14.58 (±2.37) and 0.04 (±0.005) μg ml?1 respectively. Both cypermethrin and fenvalerate remained present in blood for 36 h. The mean t1/2β) and Vdarea values were 5.56 (±0.28) h and 10.38 (±2.20) litre kg?1 for cypermethrin and 5.66 (±0.35) h and 11.31 (±2.20) litre kg?1 respectively for fenvalerate. Both cypermethrin and fenvalerate persisted in goat milk for 36 h. The t1/2β) and AUC values of fenvalerate were 7.37 (±1.84) h and 122.38 (±11.65) μg h ml?1 whilst the corresponding values for cypermethrin were 6.66 (±1.54) h and 99.48 (±7.81) μg h ml?1 in milk respectively.  相似文献   

6.
Laying hens were treated daily for 14 days with oral doses of [14C-phenoxy]cypermethrin (1.52 mg day?1, 0-7 mg kg?1) formulated on a small quantity of diet. Radioactivity in the eggs reached a plateau value of 0.05 μg equivalents g?1 8 days after the start of dosing. Most of the residue was found in the yolk and was a mixture of cypermethrin and material which was closely associated with neutral lipids and phosphatidyl cholines. Four and a half hours after the last dose, the birds were killed and selected tissues were taken for analysis. The highest residue was found in the liver. This was composed of cypermethrin and a mixture of very polar metabolites which were not hydrolysed to significant amounts of 3-phenoxybenzoic acid or its 4-hydroxy derivative.  相似文献   

7.
Duplicate field trials were carried out on bulk wheat in commercial silos in Queensland and New South Wales. Laboratory bioassays on samples of treated grain at intervals over 8 or 9 months storage using malathion-resistant strains of insects established that treatments were generally effective. Cyfluthrin (2 mg kg?1) plus piperonyl butoxide (10 mg kg?1) and cypermethrin (4 mg kg?1) plus piperonyl butoxide (10 mg kg?1) completely controlled two strains of Sitophilus oryzae L. Control of a third strain by the cypermethrin combination was incomplete after 11/2 months and neither controlled a multi-resistant laboratory strain. Both combinations were effective against Rhyzopertha dominica F., Tribolium castaneum Herbst and Ephestia cautella Walker. No natural infestation developed in the treated grain in any silo. Mean residues of cyfluthrin and cypermethrin after 9 months storage were 58% and 52% of the calculated application rates, respectively. Compared with overall concentrations in the wheat, residue levels were higher in bran and pollard and lower in white flour. During baking, residues decreased by up to 29%. Operators experienced respiratory irritation associated with exposure to both combinations and alternative formulations would be required for use of these materials in grain storage.  相似文献   

8.
During subacute toxicological testing of PYR-VU-TO2, a novel cypermethrin-like pyrethroid with a high (150:1) cis: trans ratio, its distribution in skeletal muscle and internal organ tissues of two groups of experimental sheep was investigated after oral administration of two different doses (1/10 and 1/20 of the LD10). Residual levels of PYR-VU-TO2 were also observed in sheep blood after administration of a single dose of the compound. Homogenized internal organ tissues and blood samples were extracted in light petroleum distillate+acetone for 15 min. After filtration, the extract was cleaned up on a ‘Florisil’R and sodium sulfate layer. The pyrethroid elution was processed with acetone+light petroleum distillate (2+98 by volume). Recoveries ranged from 80.7 to 93.5%. Unchanged PYR-VU-TO2 residues were determined on a 1.5-m stainless steel packed column under isothermal conditions with an electron-capture detector. The results were evaluated by the calibration curve method. The coefficients of variation were generally lower than 5% and determination limit for PYR-VU-TO2 was 20 μg kg?1. Mean unchanged PYR-VU-TO2 residues lay within a wide range. After six weeks of treatment the following order of tissue residue levels could be stated: heart>lung>muscle>spleen>kidney>liver>brain, and spleen>muscle>lung>heart>liver>kidney>brain for experimental groups I and II, respectively. Only small differences between the residues in the tissues of males and females were found in the first group (daily PYR-VU-TO2 dose of 50 mg kg?1 live weight). The experimental females of the second group (daily PYR-VU-TO2 dose of 200 mg kg?1 body weight) revealed higher levels (other than spleen) than did the males. Maximum PYR-VU-TO2 residues in sheep blood were found 24 h after administration of a single dose. Confirmation of the results was carried out by determination of 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid methyl ester by capillary GC.  相似文献   

9.
Permethrin and deltamethrin, two synthetic pyrethroid insecticides, are registered in several countries for use on lettuce. Both chemicals were applied on autumn and spring grown lettuce in the glasshouse. When applied at the normal prescribed dose rates of 25 and 12.5 g a.i. ha?1, < 1 mg kg?1 of either compound was found in the lettuce at harvest, even when applied only a few days before harvest. The total amount of active ingredient applied was too low to reach the 1 mg kg?1 level when evenly applied on marketable lettuce heads weighing about 200 g each. Applying a higher dose than 25 g permethrin a.i. ha?1 or 12.5 g deltamethrin a.i. ha?1, or applying two applications in the 2 weeks prior to harvest, may well result in residue levels higher than the maximum residue limit of 1 mg kg?1 for permethrin and certainly higher than the maximum residue limit of 0.2 mg kg?1 for deltamethrin, which is more persistent.  相似文献   

10.
BACKGROUND: A mixture of trifloxystrobin and tebuconazole is excellent in controlling both powdery and downy mildew of grapes. The objective of the present work was to study the behaviour of trifloxystrobin and tebuconazole on grape berries and soil following treatment with Nativo 75 WG, a formulation containing both fungicides (trifloxystrobin 250 + tebuconazole 500 g kg?1). This study was carried out for planned registration of this mixture for use on grapes in India. RESULTS: Initial residue deposits of trifloxystrobin and tebuconazole on grapes were below their maximum residue limit (MRL) of 0.5 and 2 mg kg?1, respectively, when Nativo 75 WG was applied at the recommended dose of 175 g product ha?1. The residues dissipated gradually to 0.02 and 0.05 mg kg?1 by 30 days, and were below the quantifiable limit of 0.01 mg kg?1 at the time of harvest (60 days after the last treatment). Trifloxystrobin and tebuconazole dissipated at a pre‐harvest interval (PHI) of 36 and 34 days, respectively, from the recommended treatment dose. The acid metabolite of trifloxystrobin, CGA 321 113, was not detected in grape berries at any point in time. Soil at harvest was free of any pesticide residues. CONCLUSION: Residue levels of both trifloxystrobin and tebuconazole were below MRLs when grapes were harvested 30 days after the last of four applications of 175 g product ha?1 (trifloxystrobin 44 g AI ha?1, tebuconazole 88 g AI ha?1) under the semi‐arid tropical climatic conditions of India. Copyright © 2010 Society of Chemical Industry  相似文献   

11.
Permethrin, cypermethrin, and resmethrin were tested under field conditions as repellents to protect cattle from black flies (Simulium spp.). The chemicals were applied topically to the entire body surface of steers. Ethanolic solutions of technical permethrin, at doses of 1, 2, 4 and 6 mg a. i. kg?1 of body weight, effectively repelled black flies by preventing at least 70% of the flies present from taking a blood meal for up to 8 days, and for at least 11 days at a dose of 12 mg a. i. kg?1. Aqueous mixtures of a 20% permethrin emulsifiable concentrate (e. c.), at doses of 1, 2 and 6 mg a. i. kg?1, effectivelyrepelled black flies for 2, 10 and 11 days, respectively. Aready-to-use 5% permethrin dust, at doses of 1, 2, and 4 mg a. i. kg?1, effectively repelled black flies for 4, 5 and 8 days, respectively. Ethanolic solutions of technical cypermethrin, at doses of 1 and 2 mg a. i. kg?1, repelled black flies for 3 and 4 days, respectively. Aqueous mixtures of a 40% cypermethrin e. c., at doses of 2 and 4 mg a. i. kg?1, repelled black flies for at least 5 days. Ethanolic solutions of technical resmethrin, at doses of 2 and 6 mg a. i. kg?1, repelled black flies for 1 and 2 days, respectively.  相似文献   

12.
Residues of endosulfan insecticide (α- and β-isomers, and ‘endosulfan sulphate’) in fish and their predators were measured during and after operations to control tsetse fly in the Okavango Delta, Botswana. Six ultra-low-volume doses of endosulfan 35% e.c. (6–12 g a.i. ha?1) were applied from the air in a period of 12 weeks over 2500 km2. The concentration of residues found in living fish was up to 0.19 mg kg?1 wet wt in caudal muscle, and usually < 0.8 mg kg?1 wet wt in pooled viscera (maximum 2.8 mg kg?1). These values returned to near-normal within 3 months after cessation of spraying, but residues were still detectable after 12 months. By comparison, fish killed by spraying contained a maximum residue level (whole-body) of 1.5 mg kg?1 wet wt. The residue level in fish was approximately proportional to their fat content. Lean fish were more susceptible to poisoning than fat fish. The proportion of the ‘endosulfan sulphate’ metabolite in fish increased at least six times with respect to the parent isomers (α+β) during the period of spraying, but more advanced stages of metabolic breakdown were not monitored. Residue levels in fish predators (fish-eating birds and crocodiles) were similar to those in their prey, and the risk to them was consequently low.  相似文献   

13.
In order to obtain residue data from the application of the algicide endothal in Italian rice paddy fields, two experiments were carried out using a 50 g kg?1 granular formulation in a small pond and the same granular and two liquid formulations in actual paddy fields of the Italian rice growing area. Endothal decay in the pond water was very rapid, reaching residue levels of 0·01-1·02 mg litre?1 in two days and 0·004-0·01 mg litre?1 at the third day. The muddy soil of the pond was free from measurable endothal residues( <0·02 mg kg?1). In the paddy-field waters, the endothal decay was slower, with an average half-life time of 3·3 days, independently of the type of formulation. The actual residues in water after 6 days ranged from 0·3 to 1·3 mg litre?1 according to the initial amount of product applied, and, consequently, to the initial concentration in water. Rice samples collected at the normal harvest time from the two paddy fields, treated with three different formulations, showed no endothal residue at the minimum detectable level of 0·01 mg kg?1.  相似文献   

14.
The synergistic effect of a range of ergosterol-biosynthesis-inhibiting (EBI) fungicides and a pyrethroid insecticide was studied in the honeybee (Apis mellifera L.). Various EBI fungicides were combined separately with the pyrethroid lambda-cyhalothrin at ratios derived from their recommended application rates to represent tank-mixing in the field. The mixture was then applied topically to the thorax of honeybees, and mortality assessed 24 h post-treatment. All the fungicides tested increased the toxicity of lambda-cyhalothrin to honeybees. The fungicide propiconazole was found to have the strongest synergistic effect, decreasing the LD50 of lambda-cyalothrin from 68.0 ng bee?1 to 4.2 ng, thus having a synergistic ratio of 16.2. Hazard ratios were calculated for lambda-cyhalothrin and fungicide mixtures using a recommended application rate of 7.5 g a.i. ha?1. The hazard ratio for lambda-cyhalothrin alone was 110, but when mixed with fungicide synergists, the hazard ratio ranged from 366 with flutriafol to 1786 with propiconazole. A blank formulation of a fungicide (without the active ingredient prochloraz) had little effect on the toxicity of lambda-cyhalothrin, indicating that it is primarily the fungicide active ingredient that is responsible for the synergistic effect. The results are discussed in terms of the potential hazard posed by pesticide synergism to honeybees in the field.  相似文献   

15.
The fate of 4-chlorophenylurea in soils was studied with two preparations: one labelled with 14C in the phenyl ring and the other in the carbonyl group. The initial dose of 1 mg kg?1 decreased to 50% in about 5 weeks in aerobic sandy clay and in about 16 weeks in anaerobic hydrosoil. Soil treatment with each of the preparations resulted in the release of [14C]carbon dioxide, pointing to decarbonylation and ring opening. The fraction of non-extractable (soil-bound) radioactivity increased during incubation. Quantities of ring-14C-labelled and carbonyl-14C-labelled bound residues differed strongly in the aerobic soil but only slightly in the anaerobic hydrosoil. It is assumed that two sorts of bound residues are formed from 4-chlorophenylurea: one is fairly stable and might consist of bound 4-chloroaniline or its transformation products, whereas the other is presumed to be a degradable derivative of 4-chlorophenylurea.  相似文献   

16.
The persistence patterns of three synthetic pyrethroids—fenvalerate, tau-fluvalinate, lambda-cyhalothrin—and an organophosphorus insecticide, monocrotophos, on eggplant (Solanum melongena L.) have been evaluated. The extractable residues ranged from 0.05 to 0.45, 0.01 to 0.40, 0.003 to 0.09 and 0.09 to 0.32 μg g?1 for fenvalerate, tau-fluvalinate, lambda-cyhalothrin and monocrotophos, respectively. Fenvalerate was the most persistent among the four, followed by monocrotophos, lambda-cyhalothrin and tau-fluvalinate. The Maximum Residue Limit (MRL) of these pesticides on S. melongena has not yet been documented. The present data may be useful for establishing MRL and assessing the amount of pesticide residues in this vegetable.  相似文献   

17.
Blackcurrants, treated with 0.1 kg of 2,4,5-T ha?1 (as esters of mixed C4–C6 alcohols; ‘Tormona 80’), contained 0.1 mg of 2,4,5-T residues kg?1 in the berries at ripeness 29 days after treatment. Total residues in the berries were not reduced during growth and ripening, although the residue concentrations declined in the same period due to growth dilution. In spinach leaves from old plants, treated with 0.1 kg ha?1, 0.05 mg of 2,4,5-T kg?1 was found 14 days after treatment. Fodder peas showed no residues (< 0.002 mg kg?1) at harvest 62 days after treatment with 2,4,5-T esters. After application of 0.1 kg ha?1 on potato plants, the disappearance of 2,4,5-T was rapid during the first month, but residues were translocated into the tubers and reached a constant level of 0.02 mg kg?1 after 1 month until harvest at 108 days after treatment. In all crops, visible effects were observed after treatment with 0.1 kg ha?1. After the application at 0.01 kg ha?1, phytotoxic effects were observed only in blackcurrants, but negligible residues were found in all the test crops.  相似文献   

18.
In a greenhouse metabolism study, sunflowers were seed‐treated with radiolabelled imidacloprid in a 700 g kg?1 WS formulation (Gaucho® WS 70) at 0.7 mg AI per seed, and the nature of the resulting residues in nectar and pollen was determined. Only the parent compound and no metabolites were detected in nectar and pollen of these seed‐treated sunflower plants (limit of detection <0.001 mg kg?1). In standard LD50 laboratory tests, imidacloprid showed high oral toxicity to honeybees (Apis mellifera), with LD50 values between 3.7 and 40.9 ng per bee, corresponding to a lethal food concentration between 0.14 and 1.57 mg kg?1. The residue level of imidacloprid in nectar and pollen of seed‐treated sunflower plants in the field was negligible. Under field‐growing conditions no residues were detected (limit of detection: 0.0015 mg kg?1) in either nectar or pollen. There were also no detectable residues in nectar and pollen of sunflowers planted as a succeeding crop in soils which previously had been cropped with imidacloprid seed‐treated plants. Chronic feeding experiments with sunflower honey fortified with 0.002, 0.005, 0.010 and 0.020 mg kg?1 imidacloprid were conducted to assess potential long‐term adverse effects on honeybee colonies. Testing end‐points in this 39‐day feeding study were mortality, feeding activity, wax/comb production, breeding performance and colony vitality. Even at the highest test concentration, imidacloprid showed no adverse effects on the development of the exposed bee colonies. This no‐adverse‐effect concentration of 0.020 mg kg?1 compares with a field residue level of less than 0.0015 mg kg?1 ( = limit of detection in the field residue studies) which clearly shows that a sunflower seed dressing with imidacloprid poses no risk to honeybees. This conclusion is confirmed by observations made in more than 10 field studies and several tunnel tests. © 2001 Society of Chemical Industry  相似文献   

19.
A goat was dosed orally with [14C]tefluthrin, twice daily for 4 days, at a rate equivalent to 10.9 mg kg?1 in its diet. Within 16 h of the final dose, 70.1% of the dose had been excreted (urine 41.4%, faeces 28.7%). Extensive metabolism occurred in the goat by ester cleavage and oxidation at a variety of positions on the molecule. Low radioactive residues were detected in the milk (0.076 mg kg?1), fat (0.076 mg kg?1) and muscle (0.016 mg kg?1), with tefluthrin as the largest individual component of the residue (milk 66.5%, fat 76.7%, muscle 34.2%). Higher residues were present in the kidney (0.3 mg kg?1) and liver (1.0 mg kg?1) and only a small percentage of this residue was due to tefluthrin (kidney 3.4%, liver 6.1%). The remainder of the residue in the kidney and liver was a complex mixture of metabolites. Most of the kidney metabolites were identified, but a high proportion of the liver residue was due to six unidentified polar compounds.  相似文献   

20.
Two procedures are described for the determination of residues of triadimenol and compared on cereal material. After extraction, purification is carried out by Florisil column chromatography in method I and by semi-preparative High-Performance Liquid Chromatography in method II. Triadimenol residues are quantified by gas chromatography with a thermoionic detector. With method I, interference was observed but not with method II. This specific procedure has been tested on other plant materials. Recoveries in the range of 90–98% indicate that this procedure is suitable for residue analysis of this fungicide with detection limits of 0·008 mg kg?1 in wheat grains, 0·03 mg kg?1 in wheat straw and 0·004–0·008 mg kg?1 in other plants. Maximum residue limits in France are: 0·1 mg kg?1 in grain, 2·0 mg kg?1 in straw and 1·0 mg kg?1 in other vegetables and fruit.  相似文献   

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