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Application of dispersive liquid—liquid microextraction for the analysis of organophosphorus pesticides in Hawthorn (Crataegus pinnatifida var. major) juice samples

100%

Ren Q. , Xia T.

2016

tom Vol. 28, no. 3

403--414

Dispersive liquid–liquid microextraction (DLLME) coupled with gas chromatography equipped with flame photometric detection (GC—FPD) is introduced to extract and determine the fifteen organophosphorus pesticides (OPPs) in hawthorn (Crataegus pinnatifida var. major) juice samples. Some parameters affecting the DLLME efficiency, such as the type and volume of extraction and dispersive solvents, extraction time, and salt concentration, were studied and optimized. The optimized extraction and dispersive solvents are trichloroethane and acetonitrile, respectively. Good linearity was ranged from 0.5 to 100 ng mL−1 with correlation coefficients from 0.9991 to 0.9999. The limits of quantification (LOQs) varied from 0.15 to 0.3 ng mL−1, and the limits of detections (LODs) ranged from 0.05 to 0.1 ng mL−1. The relative standard deviations (RSDs) varied from 1.0% to 2.8% (n = 6) with the relative recoveries in the range of 85.6–119.1%. The method was successfully applied in the determination of OPPs in ten commercial hawthorn juice samples. The chlorpyrifos was detected in one sample.

Effect of alpha-cypermethrin and chlorpyrifos in a 28-day study on free radical parameters and cholinesterase activity in Wistar rats

58%

Wielgomas B. , Krechniak J.

tom 16

nr 1

In the current study the influence of single compounds and concurrent exposure to popular insecticides: organophosphate (OP) – chlorpyrifos (CPF) and synthetic pyrethroid (PYR ) – α-cypermethrin (CM) on some oxidative stress parameters and cholinesterase (ChE) activity in rats was investigated. Animals received by gavage 10 mg of single compounds or 5 mg of each per kg bw daily in rapeseed oil for 14 and 28 days. Concentrations of total thiols and TBARS, activity of catalase and cholinesterase were measured in tissues. Total thiol concentrations declined in plasma in all experimental groups after 14 and 28 days, while in liver a decrease was noted after only 14 days in animals receiving CPF and after 28 days in rats treated with CM alone with a mixture of pesticides. Lipid peroxidation presented as TBARS concentration was elevated mostly after 2 weeks of exposure in brain and liver but not in plasma in all experimental groups. Catalase activity increased in erythrocytes in all groups treated with insecticides, while in liver CM administered alone reduced the activity of the enzyme. Cholinesterase was markedly depressed to a different degree in plasma and brain of animals receiving CPF alone or in combination, while CM did not significantly elevate brain ChE. The results of this study seem to indicate that CM and CPF apart from known modes of action demonstrate their toxicity also through free radical mediated mechanisms. It is also evident that CM administered with CPF does not affect the cholinesterase inhibition generated by the latter.

Effects of CGP 39551 in acute experimental intoxication with fluostigmine

58%

Galecka E. , Gidynska T. , Jakowicz I. , Rump S.

nr 1