Phytochemical constituents and in vitro radical scavenging activity of different Aloe species.

The phytochemical profile of Aloe barbadensis Mill. and Aloe arborescens Mill. was investigated using colorimetric assays, triple quadrupole and time-of-flight mass spectrometry, focusing on phenolic secondary metabolites in the different leaf portions.

Performance and matrix effect observed in QuEChERS extraction and tandem mass spectrometry analyses of pesticide residues in different target crops.

The method performance and matrix effect related to quantitative determination of pesticide residues was assessed after QuEChERS extraction and LC-MS-MS analysis. Dicloran, phosmet and phosmet-oxon, pirimiphos-methyl, and BNOA were analyzed in peach, apple, melon, cereals, tomato, and strawberry. The matrix effects, as well as recovery and process efficiencies, were determined for a fungicide, two insecticides, and a plant growth regulator.

Rapid determination of lycopene and β-carotene in tomato by liquid chromatography/electrospray tandem mass spectrometry.

Background: The tomato fruit is a dietary source of carotenoids, bioactive antioxidant compounds that play an important role in the prevention of degenerative diseases. Several extraction and detection techniques regarding carotenoids in tomatoes can be found in the literature, mainly based on high-performance liquid chromatography separation and ultraviolet-visible detection.

Results: The best extraction conditions and tandem mass spectrometry (MS) analysis were evaluated: lycopene and β-carotene were extracted in a cyclohexane/ethyl acetate mixture without the addition of antioxidants, next separated by liquid chromatography on a C(18) column and then determined through electrospray tandem MS.

Residues of pirimiphos-methyl in cereals and processed fractions following post harvest spray application.

The aim of this work was to comparatively assess the persistence of pirimiphos methyl residues in cereals and in their milling fractions after spray application in post harvest. An analytical method, based on a slightly modified QuEChERS extraction followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) determination was validated: mean recovery was in the range 73% to 92% depending on the spiking level, and precision as RSD ranged from 11% to 16%. The analysis of treated samples revealed that pirimiphos-methyl residues were highly persistent and that no differences could be observed between wheat, durum wheat and oat.

Residues of the herbicide fenoxaprop-P-ethyl, its agronomic safener isoxadifen-ethyl and their metabolites in rice after field application.

Background: Fenoxaprop-P-ethyl is a herbicide used on cereals and in particular on rice, the degradation of which leads to several relevant metabolites. The herbicide is used together with an agronomic safener such as isoxadifen-ethyl, which also generates some metabolites. The present work was aimed at developing and validating an analytical method for the determination of the above parent compounds and their main metabolites in the edible fractions of rice.

Effect of different formulations on tebuconazole residues in stone fruits.

Background: The correlation between pesticide residue levels and formulation of an active substance is often not considered, even if it is reasonable to expect some differences arising from behaviour during dilution and spraying, from adhesion to plant and from degradation. An experimental study to investigate the magnitude of tebuconazole residues as a function of different tebuconazole formulated products was carried out in Italy. The fungicide was applied as wettable powder (WP) and water-dispersible granule (WG) formulations to peach, plum, apricot and nectarine orchards, on four different sites.

[Field studies: legal framework and implementation].

The Decree DL.vo no. 194/95 prescribes compliance with correctness and quality criteria in laboratory and field studies when experimental data on pesticides are to be submitted to the regulatory authority.