Search results for "Pesticide residues"

Pesticides in the Ebro River basin: Occurrence and risk assessment

2016

In this study, 50 pesticides were analyzed in the Ebro River basin in 2010 and 2011 to assess their impact in water, sediment and biota. A special emphasis was placed on the potential effects of both, individual pesticides and their mixtures, in three trophic levels (algae, daphnia and fish) using Risk Quotients (RQs) and Toxic Units (TUs) for water and sediments. Chlorpyrifos, diazinon and carbendazim were the most frequent in water (95, 95 and 70% of the samples, respectively). Imazalil (409.73 ng/L) and diuron (150 ng/L) were at the highest concentrations. Sediment and biota were less contaminated. Chlorpyrifos, diazinon and diclofenthion were the most frequent in sediments (82, 45 and 2…

Simultaneous clean up of fish fat containing low levels of residues and separation of PCB from chlorinated pesticides by thin-layer chromatography

1974

Multiresidue analysis of organic pollutants by in-tube solid phase microextraction coupled to ultra-high performance liquid chromatography-electrospr…

2013

In this work, in-tube solid phase microextraction (IT-SPME) coupling with ultra-high-pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) multiresidue analytical method has been proposed for the first time for on-line enrichment of 9 analytes included in Water Frame Directive 2000/60/EC (WFD). The device was equipped with a GC TRB-5 capillary column, used as pre-concentration loop, and two conventional six-port injection valves. Water sample and desorption solvent volumes were tested. The optimum conditions were 4mL of processed sample followed by elution with 40μL of methanol. The analytes were detected with a mass spectrometer after being ionized positively using an elect…

Analysis of carbamate and phenylurea pesticide residues in fruit juices by solid-phase microextraction and liquid chromatography–mass spectrometry

2007

A new analysis method to detect carbamates and phenylurea pesticide residues in fruit juices was developed using solid-phase microextraction (SPME) coupled with liquid chromatography-single quadrupole mass spectrometry (LC/MS) and liquid chromatography-quadrupole ion trap mass spectrometry (LC/QIT-MS). The pesticide residues present in watery matrices as fruit juices were extracted using three types of fibers: 50-microm Carbowax/templated resin (CW/TPR), 60-mum poly(dimethylsiloxane)/divinylbenzene (PDMS/DVB) and 85-microm polyacrylate. The different extraction conditions were evaluated choosing as the best parameters 90 min (time), 20 degrees C (temperature) and 1 ml (volume). After extrac…

A model for the formation and degradation of bound residues of the herbicide 14C-isoproturon in soil

1999

Abstract The humic monomer catechol was reacted with 14 C-isoproturon and some of its metabolites, including 14 C-4-isopropylaniline, in aqueous solution under a stream of oxygen. Only in the case of 14 C-4-isopropylaniline, incorporation in oligomers, in fulvic acid-like polymers, and in humic acid-like polymers was observed. The main oligomer was identified by mass spectrometry as 4,5-bis-(4-isopropylphenylamino)-3,5-cyclohexadiene-1,2-dione. Oligomers and polymers containing bound 14 C-4-isopropylaniline were subjected to biodegradation studies in a loamy agricultural soil during 55 days by quantifying 14 CO 2 evolved. In all cases, significant mineralization rates could be determined, w…

Immunoreagent generation and competitive assay development for cyprodinil analysis.

2012

Cyprodinil is an anilinopyrimidine fungicide applied worldwide for the prevention and treatment of highly destructive plant diseases in a large variety of crops, including cereals, fruits, and vegetables. This paper describes the development of the first reported immunoassays for cyprodinil. Two original haptens have been synthesized and conjugated to different carrier proteins, and polyclonal antibodies have been produced. Moreover, competitive enzyme-linked immunosorbent assays have been developed and characterized for the analysis of this widely used pesticide. The influence of organic solvents and buffer conditions over the assay analytical parameters was studied. The IC 50 values of th…

Fungicide multiresidue monitoring in international wines by immunoassays

2015

24 pages, 5 figures, 1 table. -- Available online 10 November 2015.

Ultra-High-Performance Liquid Chromatography Coupled with Quadrupole Orbitrap High-Resolution Mass Spectrometry for Multi-Residue Analysis of Mycotox…

2020

Cannabidiol (CBD) food supplements made of Cannabis sativa L. extracts have quickly become popular products due to their health-promoting effects. However, potential contaminants, such as mycotoxins and pesticides, can be coextracted during the manufacturing process and placed into the final product. Accordingly, a novel methodology using ultra-high-performance liquid chromatography coupled with quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) was developed to quantify 16 mycotoxins produced by major C. sativa fungi, followed by a post-target screening of 283 pesticides based on a comprehensive spectral library. The validated procedure was applied to ten CBD-bas…

Pesticide monitoring in the basin of Llobregat River (Catalonia, Spain) and comparison with historical data.

2014

Through an extensive sampling in the Llobregat River basin, the presence of 50 currently used pesticides in water, sediment, and biota was assessed. Pesticides were detected primarily in water (up to 56% of the analytes), whereas their presence in sediments was more intermittent, and in biota was scarce. Those at high concentrations in water were the benzimidazoles (carbendazim in 22% of the samples up to 697ngL-1), the organophosphorus (malathion in 54% of the samples up to 320ngL-1), and the ureas (diuron in 54% of the samples up to 159ngL-1). However, this pattern differed in sediments and biota, which were contaminated primarily with organophosphorus (higher Kow) (chlorpyrifos 93% of se…

Screening of currently used pesticides in water, sediments and biota of the Guadalquivir River Basin (Spain)

2013

The occurrence of 50 currently used pesticides and their transformation products in surface and waste waters, sediment and fish in the Guadalquivir River Basin was determined in 2010 and 2011. After selective sample extraction, pesticides were identified and quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The contamination profile in water and sediments is marked by the presence of organophosphorus and triazines. Transformation products were even at higher concentrations than parent pesticides. A wider range of pesticides was present in water than in sediments but none of them were detected in fish. The mean concentrations ranged from 0.2 to 13.0 ng/L in …