Search results for "Carbendazim"
showing 10 items of 13 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…
Effect of carbendazim and physicochemical factors on the growth and ochratoxin A production of Aspergillus carbonarius isolated from grapes.
2007
Carbendazim is a systemic fungicide that is commonly used on several crops (tobacco, fruit, vegetables, cereals, etc.). This fungicide is used to control fungal infections in vineyards. It is indicated against Botrytis cinerea, Uncinula necator, Plasmopara viticola and other fungi and can be used either alone or coupled with other fungicides. However, there is a lack of in-depth studies to evaluate its effectiveness against growth of Aspergillus carbonarius isolated from grapes and OTA production. A medium based on red grape juice was used in this study. Preliminary studies were performed at 0.98 a(w) and 25 degrees C using carbendazim concentrations over a wide range (1-2000 ng/ml medium) …
Comparison of microextraction procedures to determine pesticides in oranges by liquid chromatography-mass spectrometry.
2002
A liquid chromatographic-mass spectrometric method has been developed for the determination of bitertanol, carbendazim, fenthion, flusilazole, hexythiazox, imidacloprid, methidathion, methiocarb, pyriproxyfen and trichlorfon. Two procedures, based on stir bar sorptive extraction (SBSE) and matrix solid-phase dispersion (MSPD), have been evaluated for the extraction of these compounds in oranges. Their respective advantages and disadvantages are also discussed. The recoveries obtained by MSPD ranged from 47 to 96% and the relative standard deviations (RSDs) ranged from 1 to 15%, whereas with the SBSE method the recoveries were between 8 and 84% and the RSDs between 4 and 16%. Although, the l…
Predictive assessment of ochratoxin A accumulation in grape juice based-medium by Aspergillus carbonarius using neural networks
2009
Aims: To study the ability of multi-layer perceptron artificial neural networks (MLP-ANN) and radial-basis function networks (RBFNs) to predict ochratoxin A (OTA) concentration over time in grape-based cultures of Aspergillus carbonarius under different conditions of temperature, water activity (a(w)) and sub-inhibitory doses of the fungicide carbendazim. Methods and Results: A strain of A. carbonarius was cultured in a red grape juice-based medium. The input variables to the network were temperature (20-28 degrees C), a(w) (0 center dot 94-0 center dot 98), carbendazim level (0-450 ng ml(-1)) and time (3-15 days after the lag phase). The output of the ANNs was OTA level determined by liqui…
Simultaneous determination of imidacloprid, carbendazim, methiocarb and hexythiazox in peaches and nectarines by liquid chromatography–mass spectrome…
2002
Abstract A liquid chromatographic (LC) atmospheric pressure chemical ionization mass spectrometric (MS) method is described for determining imidacloprid, carbendazim, methiocarb and hexythiazox in peaches and nectarines. The samples were extracted with ethyl acetate and anhydrous sodium sulfate. Recoveries yield for spiking samples were ranged from 64±9% (R.S.D) for carbendazim to 108±14% (R.S.D.) for hexythiazox at the concentration of 0.1 mg kg−1 (n=5). The correlation coefficients were greater than 0.998 over the range between 0.02 and 2 mg kg−1. The limits of quantitation (LOQ) were 0.02 mg kg−1 for all the pesticides. The applicability of the method to detect and quantify imidacloprid,…
On-line preconcentration strategies for analyzing pesticides in fruits and vegetables by micellar electrokinetic chromatography.
2007
Five pesticides (fludioxonil, procymidone, pyriproxyfen, dinoseb and carbendazim) were separated in reversed migration micellar electrokinetic chromatography (RM-MEKC) using 20 mmol l(-1) phosphate buffer at pH 2.3, containing 25 mmol l(-1) sodium dodecylsulfate and 10% methanol. Three on-line concentration strategies, sweeping (SW), normal stacking with reversed migration and a water plug (SRW) and stacking with reverse migration and removal of sample matrix using polarity switching (SRMM), were compared. About 10-, 30- and 50-fold increases in detection sensitivity, compared with standard hydrodynamic injection (5 s at 0.5 psi), were observed with SW, SRW and SRMM, respectively. Limits of…
Particle size distributions of currently used pesticides in ambient air of an agricultural Mediterranean area
2014
This work presents first data on the particle size distribution of 16 pesticides currently used in Mediterranean agriculture in the atmosphere. Particulate matter air samples were collected using a cascade impactor distributed into four size fractions in a rural site of Valencia Region, during July to September in 2012 and from May to. July in 2013. A total of 16 pesticides were detected, including six fungicides, seven insecticides and three herbicides. The total concentrations in the particulate phase (TSP: Total Suspended Particulate) ranged from 3.5 to 383.1 pg m(-3). Most of the pesticides (such as carbendazim, tebuconazole, chlorpyrifos-ethyl and chlorpyrifos-methyl) were accumulated …
Analysis of post-harvest fungicides by micellar electrokinetic chromatography.
2001
A method based on solid-phase extraction (SPE) and micellar electrokinetic chromatography (MEKC) was developed for the simultaneous determination of carbendazim, imazalil, methylthiophanate, O-phenylphenol, prochloraz, procimidone, thiabendazole and triadimefon residues in grape, lettuce, orange and tomato. Selectivity and resolution were studied changing the pH and the concentration of the buffer, the type and concentration of surfactant and the methanol content in the mobile phase. A buffer consisting of 4 mM borate with 75 mM sodium cholate (pH 9.2) gave the best results. The recoveries of the fungicides in spiked fruit and vegetable samples ranged from 30 to 105%, and the limits of dete…
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…
Micellar enhanced fluorimetric determination of carbendazim in natural waters
1994
Abstract A micellar enhanced flow-injection fluorimetric method was developed for the determination of carbendazim in natural water samples. The method is based on the direct injection of 500 μ1 of water into a three-channel flow manifold in which the samples are merged with a buffer solution and subsequently with a surfactant solution. Two alternative procedures were used: one based on the use of sodium dodecyl sulphate micelles in 0.1 M HCl, which permits a 2.6-fold enhancement of the sensitivity found in the absence of micelles to be obtained, and the other based on the use of cetyltrimethylammonium bromide in 0.1 M NaOH, which provides a 11.6-fold enhancement of sensitivity and a limit …