Search results for "Omethoate"
showing 5 items of 5 documents
Retrospective screening of pesticide metabolites in ambient air using liquid chromatography coupled to high-resolution mass spectrometry
2015
A new methodology for the retrospective screening of pesticide metabolites in ambient air was developed, using liquid chromatography coupled to Orbitrap high-resolution mass spectrometry (UHPLC-HRMS), including two systematic workflows (i) post-run target screening (suspect screening) and (ii) non-target screening. An accurate-mass database was built and used for the post-run screening analysis. The database contained 240 pesticide metabolites found in different matrixes such as air, soil, water, plants, animals and humans. For non-target analysis, a "fragmentation-degradation" relationship strategy was selected. The proposed methodology was applied to 31 air samples (PM10) collected in the…
Use of SPME extraction to determine organophosphorus pesticides adsorption phenomena in water and soil matrices
2005
Solid-phase micro extraction (SPME) coupled with GC enables rapid and simple analysis of organophosphorus pesticides in a range of complex matrices. Investigations were made into the extraction efficiencies from water of six organophosphorus insecticides (methamidophos, omethoate, dimethoate, parathion methyl, malathion, and parathion ethyl) showing a wide range of polarities. Three SPME fibres coated with different stationary phases, polydimethylsiloxane, polyacrylate, and carbowax-divinylbenzene (CW-DVB), were investigated. Water was spiked with the pesticides at concentrations from 1 to 0.01 µg mL-1, and the solutions used for optimization of the procedure. The CW-DVB fibre, with a 65 µm…
Rapid screening of organophosphorus pesticides in honey and bees by liquid chromatography—Mass spectrometry
2002
Twenty-two organophosphorus pesticide residues were simultaneously determined in honey and honeybee samples by extraction procedures based on solid-phase and liquid chromatography-atmospheric pressure chemical ionization-mass in positive and negative ionization modes. Pesticides in honeybee samples were extracted by matrix solid phase dispersion with C18 silica and subsequently eluted with a mixture of dichloromethane-methanol (85∶15, v/v). The average recoveries from spiked honeybees (0.5–10 μg g−1) ranged from 76% for coumaphos to 100% for omethoate, with relative standard deviations between 3 and 17%. Limits of detection were ≤0.13 μg g−1 and limits of quantification were ≤0.43 μg g−1. H…
Multi-residue analysis of 30 currently used pesticides in fine airborne particulate matter (PM 2.5) by microwave-assisted extraction and liquid chrom…
2009
A confirmatory and rapid procedure has been developed for the determination of 30 currently used pesticides (CUP) in fine airborne particulate matter (PM 2.5) at trace level. The proposed method includes extraction of PM 2.5-bound pesticides by microwave-assisted extraction (MAE) followed by a direct injection into LC-MS/MS. The main parameters affecting the MAE extraction (time, temperature and volume of solvent) were optimised using statistical design of experiments (DoE). The matrix effect was also evaluated. Recoveries ranged from 72 to 109% and the limit of quantification (LoQ) was 32.5 pg m(-3) for chlorpyrifos, 13.5 pg m(-3) for fenhexamid, imazalil and prochloraz, and 6.5 pg m(-3) f…
GC–MS characterization of contemporary pesticides in PM10 of Valencia Region, Spain
2012
Pesticides in the inhalable fraction of particulate matter (PM10) should be well tracked in order to contribute information to future exposure assessment in individuals of the general public. A total of 40 current-used pesticides and metabolites were searched for in ambient air samples collected from January through December 2010. The samples were taken from one remote, one urban and three rural sites in Valencia Region (Spain) and analyzed using liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS). In the PM10 fraction 17 pesticides and metabolites were detected overall, two of them currently banned (carbofuran and omethoate, although the latter is a metabolite of the pe…