Search results for "Insecticide"

Gas chromatographic determination of organochlorine pesticides in cow milk.

2004

A gas chromatographic method of use in determining the following organochlorine pesticides in cow milk has been adapted and validated: alpha-hexachlorocyclohexane (alpha-HCH), beta-HCH, lindane, delta-HCH, hexachlorobenzene, aldrin, heptachlor, heptachlor epoxide, mirex, 2,4-dichlorodiphenyltrichloroethane (2,4-DDT), 4,4-DDT, 2,4-dichlorodiphenyldichloroethane (2,4-DDD), 4,4-DDD, 2,4-dichlorodiphenylethane (2,4-DDE) and 4,4-DDE. The method studied consists of three steps: the extraction of fat by centrifugation, mixing with anhydrous sodium sulfate, and transfer to a glass column and elution with hexane; purification of the extract via concentrated sulfuric acid treatment; and determination…

Assessment of Pesticide Residues in Honey Samples from Portugal and Spain

2003

Fifty samples of honey collected from local markets of Portugal and Spain during year 2002 were analyzed for 42 organochlorine, carbamate, and organophosphorus pesticide residues. An analytical procedure based on solid-phase extraction with octadecyl sorbent followed by gas chromatography-mass spectrometry (GC-MS), for organochlorines, and by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), for organophosphorus and carbamates, has been developed. Recoveries of spiked samples ranged from 73 to 98%, except for dimethoate (40%), with relative standard deviations from 3 to16% in terms of repeatability, and from 6 to 19% in terms of reproducibility. …

Determination of urea-derived pesticides in fruits and vegetables by solid-phase preconcentration and capillary electrophoresis

2001

A multiresidue analytical method based on solid-phase extraction (SPE) enrichment combined with capillary electrophoresis (CE), using micellar electrokinetic capillary chromatography (MEKC), was developed to determine ten substituted urea pesticides in orange and tomato samples. Several factors such as pH, composition and concentration of the buffer, concentration of surfactant, addition of organic solvent, and working voltage were optimized to obtain the best compound separation in the shortest time. Separation can be achieved in 7 min using a micellar aqueous pH 9 buffer composed of 4 mM borate and 35 mM sodium dodecyl sulfate. After an SPE procedure, which provided a 10-fold enrichment, …

Essential oils from three Algerian medicinal plants (Artemisia campestris, Pulicaria arabica, and Saccocalyx satureioides) as new botanical insectici…

2020

Medicinal and aromatic plants represent an outstanding source of green active ingredients for a broad range of real-world applications. In the present study, we investigated the insecticidal potential of the essential oils obtained from three medicinal and aromatic plants of economic importance in Algeria, Artemisia campestris, Pulicaria arabica, and Saccocalyx satureioides. Gas chromatography coupled with mass spectrometry (GC-MS) was used to study the essential oil chemical compositions. The three essential oils were tested against a mosquito vectoring filariasis and arboviruses, i.e., Culex quinquefasciatus, a fly pest acting also as pathogens vector, Musca domestica, and an agricultural…

Solid-phase microextraction-liquid chromatography-mass spectrometry applied to the analysis of insecticides in honey

2007

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 t…

Assessment of the toxicity of a pesticide with a two-generation reproduction test using Daphnia magna.

2000

Abstract Daphnia magna (F 0 generation) were exposed during 21 days to different diazinon concentrations. Offspring (animals from the first and third brood: F 1 (1st) and F 1 (3rd), respectively) were transferred to a free pesticide medium during a 21-day recovery period. The algae Nannochloris oculata (5×10 5 cells/ml) were used as food. In this recovery study, survival, growth and reproduction (mean total young per female, mean brood size, onset of reproduction and mean number broods per female) were assessed as individual parameters, and the intrinsic rate of natural increase ( r ) as population parameter for F 1 (1st and 3rd broods) daphnids. Reproduction as well as survival was still r…

Physiological Perturbations in Several Generations of Daphnia magna Straus Exposed to Diazinon

2000

Abstract Daphnia magna was exposed to sublethal diazinon concentrations (0.05, 0.1, 0.5, 0.75, and 1.0 ng/L) for 21 days. The algae Nannochloris oculata (5×10 5 cells/mL) was used to feed the daphnids. Chronic toxicity tests were carried out using neonates of F 1 (first brood) and F 1 (third brood) offspring generations from parentals (F 0 ) preexposed to the organophosphate. The effect of diazinon on survival, reproduction, and growth was monitored for the selected daphnid generations. The parameters used to evaluate pesticide effect on reproduction were mean total young per female, mean brood size, time to first reproduction, mean number broods per female, and intrinsic rate of natural in…

PERSISTENCE OF SOME PESTICIDES IN THE AQUATIC ENVIRONMENT

1992

Overproduction of the Bacillus thuringiensis Vip3Aa16 toxin and study of its insecticidal activity against the carob moth Ectomyelois ceratoniae

2015

Abstract The vip3Aa16 gene of Bacillus thuringiensis strain BUPM95 was cloned and expressed in Escherichia coli . Optimization of Vip3A16 protein expression was conducted using Plackett–Burman design and response surface methodology. Accordingly, the optimum Vip3A16 toxin production was 170 μg/ml at 18 h post-induction time and 39 °C post-induction temperature. This corresponds to an improvement of 21 times compared to the starting conditions. The insecticidal activity, evaluated against Ectomyelois ceratoniae , displayed an LC 50 value of 40 ng/cm 2 and the midgut histopathology of Vip3Aa16 fed larvae showed vacuolization of the cytoplasm, brush border membrane destruction, vesicle formati…

Toxicity of lindane, atrazine, and deltamethrin to early life stages of zebrafish (Brachydanio rerio).

1990

Fertilized eggs of zebrafish were exposed under flow-through conditions to several concentrations of the following pesticides: lindane 40, 80, 110, 130, and 150 micrograms/liter; atrazine 300, 1300, and 9100 micrograms/liter; deltamethrin 0.5, 0.8, and 1.2 micrograms/liter. Hatching, abnormalities in development (external deformations, edema, etc.), and mortality were recorded over a period of 35 days. At the end of the experiment, the body lengths of the fish were measured. Survival of juvenile fish after 35 days was reduced by increasing concentrations of all xenobiotics tested: lindane enhanced the mortality from 110 micrograms/liter and atrazine from 1300 micrograms/liter, and deltameth…