A multiresidue method for the determination of insecticides and triazine herbicides in fresh and processed olives.

A simple, rapid, and low-cost gas chromatographic multiresidue method has been developed for the analysis of pesticide residues in raw and processed olives. This has been validated for 19 insecticides and triazine herbicides, covering a wide range of polarities. The method uses low-temperature precipitation to remove lipids and gives good cleanup for gas chromatography analysis with nitrogen phosphorus and electron capture detection.

Residues of azoxystrobin from grapes to raisins.

Azoxystrobin, a fungicide of the strobilurin group, has an European Union maximum residue level (MRL) of 2 mg/kg for grapes. This work aimed to assess residues on fresh and washed grapes and on raisins following processing with (i) alkali treatment and sun drying and (ii) sun drying only. QUADRIS 25% SC was applied according to good agricultural practice for two consecutive years on a typical cv.

Long-term stability of pure standards and stock standard solutions for the determination of pesticide residues using gas chromatography.

The regular replacement of pure standards used in pesticide residue analysis laboratories and frequent preparation of stock standard solutions, both required by many accreditation bodies, impose considerable demands on a laboratory's resources. In this study, pure standards for all but one (heptenophos) of 118 different pesticides amenable to analysis by GC, and stock standard solutions (1000 microg/ml) prepared from these in toluene, acetone or ethyl acetate have been shown to be stable at < or = -20 degrees C over long periods: 4-13 and 2-8 years, respectively, for pure standards and solutions. Suitable solvents, containers and handling procedures are essential to avoid evaporation from solutions.

Biodegradation of lindane by Pleurotus ostreatus via central composite design.

The degradation of lindane was studied in liquid-agitated cultures using a commercial strain of the fungus Pleurotus ostreatus as the biodegrading organism. The biodegradation was accomplished with the action of extracellular oxidative enzymes, produced by the fungus to decompose woody substrates. Enzyme activities of manganese peroxidase and laccase were measured in a liquid mineral medium.

Determination of pesticide residues in wine using gas chromatography with nitrogen-phosphorus and electron capture detection.

A multiresidue method employing an extraction step with ethyl acetate followed by clean-up using an Isolute silica column and determination using gas chromatography with nitrogen-phosphorus and electron capture detection was validated for a wide range of pesticide residues in white and red wine. Recoveries between 70 and 110% and relative standard deviations below 20% were obtained for nearly all target analytes using matrix-matched standards. Limits of detection based on three times the signal-to-noise ratio were in the range 0.