Search results for "Pesticide residues"
showing 10 items of 89 documents
Application of ultra-high pressure liquid chromatography linear ion-trap orbitrap to qualitative and quantitative assessment of pesticide residues
2014
Abstract The analysis of pesticides residues using a last generation high resolution and high mass accuracy hybrid linear ion trap-Orbitrap mass spectrometer (LTQ-Orbitrap-MS) was explored. Pesticides were extracted from fruits, fish, bees and sediments by QuEChERS and from water by solid-phase with Oasis HLB cartridges. Ultra-high pressure liquid chromatography (UHPLC)–LTQ-Orbitrap mass spectrometer acquired full scan MS data for quantification, and data dependent (dd) MS 2 and MS 3 product ion spectra for identification and/or confirmation. The regression coefficients ( r 2 ) for the calibration curves (two order of magnitude up to the lowest calibration level) in the study were ≥0.99. Th…
Comprehensive analysis of airborne pesticides using hard cap espresso extraction-liquid chromatography-high-resolution mass spectrometry
2017
A hard cap espresso extraction procedure has been developed to recover airborne pesticides in particulate matter trapped in filters. This extraction step was made for 20s at 72°C and 19bar using 50mL of 20% (v/v) acetonitrile in water. After that, based on NaCl salting out, extracts were concentrated 22 times and analysed by ultra-high performance liquid chromatography - high resolution mass spectrometry. 35 pesticides were evaluated, as a proof of concept, being validated the whole methodology and compared the extraction method with that based on microwave assisted extraction for 20min. In short, the method avoids cross-contamination of samples, it is relatively fast and consumes only 10mL…
Effects of a glyphosate-based herbicide on survival and oxidative status of a non-target herbivore, the Colorado potato beetle (Leptinotarsa decemlin…
2018
Abstract Glyphosate is the globally most used herbicide against a wide range of weeds. Glyphosate has been considered safe to animals as it mainly targets physiological pathways in plants. However, recent toxicological studies have revealed that glyphosate can cause various toxic effects also on animals. In this study, we investigated the direct toxic effects of a glyphosate-based herbicide (GBH, Roundup® Bio) on 1) survival and 2) oxidative status of a non-target herbivore by using Colorado potato beetles (Leptinotarsa decemlineata), originating from Poland and USA, as model species. Larvae were randomly divided into three groups: 1) high concentration (100% Roundup Bio, 360 g/l), 2) low c…
Analysis of pesticides in fruits by pressurized liquid extraction and liquid chromatography-ion trap-triple stage mass spectrometry.
2005
A multi-residue method using pressurized liquid extraction (PLE) and liquid chromatography-quadrupole ion trap-triple stage mass spectrometry (LC-IT-MS(3)) has been developed for determining trace levels of pesticides in fruits. The selected pesticides can be distinguished in: benzimidazoles and azoles, organophosphorus, carbamates, neonicotinoids, and acaricides. PLE has been optimized to extract these pesticide residues from oranges and peaches by studying the effect of experimental variables on PLE efficiency. Samples were extracted at high temperature and pressure (75 degrees C and 1500psi) using ethyl acetate as extraction solvent and acidic alumina as drying agent. The recoveries obta…
Chronic cumulative risk assessment of the exposure to organophosphorus, carbamate and pyrethroid and pyrethrin pesticides through fruit and vegetable…
2015
In the present study, the chronic cumulative exposure to organophosphorus (OPs), carbamates (CBs) and pyrethroid and pyrethrin (PPs) pesticides in the region of Valencia through fruit and vegetables consumption is presented. A total of 752 samples and 84 pesticides were studied of which, 52 were OPs, 23 CBs and 9 PPs. Residue data were derived from the Valencia Region monitoring program 2007-2011 and food consumption levels from a questionnaire-based dietary survey conducted in 2010 in the same area. The relative potency factor (RPFs) approach was used to estimate chronic cumulative dietary exposure to OPs, CBs and PPs using acephate, oxamyl and deltamethrin as index compounds, respectively…
Determination of carbosulfan and its metabolites in oranges by liquid chromatography ion-trap triple-stage mass spectrometry.
2005
Liquid chromatography ion-trap mass spectrometry LC-MSn has been successfully applied to identify and confirm carbosulfan and seven of its metabolites in oranges after pressurized liquid extraction (PLE) with dichloromethane. Mass spectra of carbosulfan and its metabolites were investigated using multiple stages of mass spectrometry. Although interpretation of the fragmentation pathways, based on mass spectra, enables structural elucidation and identification of these compounds, the proposed fragmentation pathways and ion structures need verification by exact mass measurements. The analytical method--PLE and LC-MS3 --was validated: limits of quantification (LOQ) ranged from 0.01 to 0.07 mg …
Pesticide residue determination in fruit and vegetables by liquid chromatography–mass spectrometry
2000
An overview is given of pesticide residue determination in fruit and vegetables by liquid chromatography-mass spectrometry (LC-MS). Emphasis is placed on the thermospray, particle beam and atmospheric pressure ionization interfaces including advantages and drawbacks and typical detection limits. The capacity of each interface to provide useful data for identification/confirmation of analytes and the possibility of obtaining structural information for the identification of target and non-target compounds is discussed. Finally, sample preparation techniques are dealt with in relation to their influence on further LC-MS determination.
Dynamics and risk assessment of pesticides in cucumber through field experiments and model simulation
2020
Abstract Pesticides are often applied multiple times during cucumber cultivation in China. In order to obtain the residue concentrations and subsequently human health risk assessment after pesticide multiple applications, plenty of field trials have been conducted, consuming a lot of labor force and funds. The application of kinetic models can address this problem to some extent by predicting the residue values of pesticides in cucumber. In this study, a dynamic model (dynamiCROP) was applied in combination with field experiments to investigate the distribution, translocation, and dissipation after the one-time application of seven pesticides in a cucumber-soil environment. Moreover, the re…
Utilization of long duration high-volume sampling coupled to SPME-GC-MS/MS for the assessment of airborne pesticides variability in an urban area (St…
2016
Atmospheric samples have been collected between 14 March and 12 September 2012 on a 2-week basis (15 days of sampling and exchange of traps each 7 days) in Strasbourg (east of France) for the analysis of 43 pesticides. Samples (particle and gas phases) were separately extracted using Accelerated Solvent Extraction (ASE) and pre-concentrated by Solid Phase Micro-Extraction (SPME) before analysis by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Four SPME consecutive injections at distinct temperatures were made in order to increase the sensitivity of detection for the all monitored pesticides. Currently used detected pesticides can be grouped in four classes; those used i…
Determination of pyrethroid pesticide residues in fatty materials by solid-matrix dispersion partition, followed by mini-column size-exclusion chroma…
1999
The method studied uses a combination of a solid-matrix dispersion partition (SMDP) followed by high-performance size-exclusion chromatography on a minicolumn (HPmSEC) of 7.8 mm I.D. for the separation of pyrethroid (PYR) residues from fatty material. The solid-matrix dispersion extraction is carried out by absorbing a fat solution onto an Extrelut-3 cartridge (filled with a macroporous diatomaceous material) and extracting the PYR residues with acetonitrile. Up to 1 g of fatty material can be extracted with 15 ml acetonitrile. The small amount (mean +/- S.D. = 12.4 +/- 5.9 mg) of fatty material which is eluted into the acetonitrile is further removed by HPmSEC. PYR pesticide residues are c…