Pesticide occurrence in the waters of Júcar River, Spain from different farming landscapes.

A combined methodology to identify and quantify farming chemicals in the entire Júcar River basin has been developed. The procedure consisted of the application of environmental forensic criteria associating laboratory analytical samples, cartographic analysis using Geographical Information Systems (GIS) and synthetic statistical analysis. Sampling involved the collection of 15 samples in surface waters distributed alongside the Júcar River and its two main tributaries (Cabriel and Magro Rivers).

Simultaneous determination of pyrethroids and pyrethrins by dispersive liquid-liquid microextraction and liquid chromatography triple quadrupole mass spectrometry in environmental samples.

A simple and environmentally friendly dispersive liquid-liquid microextraction (DLLME) method coupled with electrospray ionization liquid chromatography triple quadrupole mass spectrometry (LC-QqQ-MS/MS) was developed for the simultaneous determination of 17 synthetic and natural pyrethroids. A comparison of solid-phase extraction (SPE) versus DLLME for water samples and only "dilute and shoot" versus the additional extract cleanup by DLLME for sediment samples is reported. Chloroform was the extracting solvent in the DLLME technique for both water and sediment samples.

Comparison of green sample preparation techniques in the analysis of pyrethrins and pyrethroids in baby food by liquid chromatography-tandem mass spectrometry.

A new selective and sensitive liquid chromatography triple quadrupole mass spectrometry method was developed for simultaneous analysis of natural pyrethrins and synthetic pyrethroids residues in baby food. In this study, two sample preparation methods based on ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and salting-out assisted liquid-liquid extraction (SALLE) were optimized, and then, compared regarding the performance criteria. Appropriate linearity in solvent and matrix-based calibrations, and suitable recoveries (75-120%) and precision (RSD values≤16%) were achieved for selected analytes by any of the sample preparation procedures.

Determination of pesticides and veterinary drug residues in food by liquid chromatography-mass spectrometry: A review.

Monitoring of pesticides and veterinary drug residues is required to enforce legislation and guarantee food safety. Liquid chromatography-mass spectrometry (LC-MS) is the prevailing technique for assessing both types of residues because LC offers a versatile and universal separation mechanism suitable for non-gas chromatography (GC) amenable and the majority of GC-amenable compounds. This characteristic becomes more relevant when LC is coupled to MS because the high sensitivity and specificity of the detector allows to apply generic sample preparation procedures, which simultaneously extract a wide variety of residues with different physico-chemical properties.

Pesticides in the Ebro River basin: Occurrence and risk assessment.

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).

Spatio-temporal patterns of pesticide residues in the Turia and Júcar Rivers (Spain).

A study was conducted on the occurrence of 50 pesticides in water and sediments of Turia and Júcar Rivers (Valencian Community, Eastern Spain) for a period of two consecutive years each, 2010/2011 and 2012/2013, respectively to assess the contribution of agriculture and urban activities on pesticide pollution. The results showed that mean concentrations of pesticides ranged from View Article and Find Full Text PDF

Assessment of two extraction methods to determine pesticides in soils, sediments and sludges. Application to the Túria River Basin.

Pressurized liquid extraction (PLE) and Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction methods were optimized for the simultaneous determination of 50 pesticides in sediment, soils and sewage sludge. For QuEChERS development, several buffers and dispersive solid-phase extraction clean-up (dSPE) sorbents were tested. In the PLE method, several parameters affecting the extraction efficiency, such as organic solvent, amount of sample, cell size, temperature, pressure, static time, number of cycles and % of flush, as well as sorbent used for the on-line clean up, were also evaluated.

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

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 697 ng L(-1)), the organophosphorus (malathion in 54% of the samples up to 320 ng L(-1)), and the ureas (diuron in 54% of the samples up to 159 ng L(-1)).

Transcriptomic, biochemical and individual markers in transplanted Daphnia magna to characterize impacts in the field.

Daphnia magna individuals were transplanted across 12 sites from three Spanish river basins (Llobregat, Ebro, Jucar) showing different sources of pollution. Gene transcription, feeding and biochemical responses in the field were assessed and compared with those obtained in re-constituted water treatments spiked with organic eluates obtained from water samples collected at the same locations and sampling periods. Up to 166 trace contaminants were detected in water and classified by their mode of action into 45 groups that included metals, pharmaceuticals, pesticides, illicit drugs, and other industrial compounds.

Perfluoroalkyl substance contamination of the Llobregat River ecosystem (Mediterranean area, NE Spain).

The occurrence and sources of 21 perfluoroalkyl substances (PFASs: C4-C14, C16, C18 carboxylate, C4, C6-C8 and C10 sulfonates and C8 sulfonamide) were determined in water, sediment, and biota of the Llobregat River basin (NE Spain). Analytes were extracted by solid phase extraction (SPE) and determined by liquid chromatography triple quadrupole mass spectrometer (LC-QqQ-MS). All samples were contaminated with at least one PFAS, being the most frequently found perfluorobutanoate (PFBA), perfluorooctanoate (PFOA) and perfluorooctane sulfonate (L-PFOS).

Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry to identify contaminants in water: an insight on environmental forensics.

Ultra-high pressure liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QqTOF-MS) acquiring full scan MS data for quantification, and automatic data dependent information product ion spectra (IDA-MS/MS) without any predefinition of the ions by the user was checked for identifying organic contaminants in water samples. The use of a database with more than 2000 compounds achieved high confidence results for a wide number of contaminants based upon retention time, accurate mass, isotopic pattern and MS/MS library searching. More than 20 contaminants, mostly pharmaceuticals, but also mycotoxins and polyphenols were unambiguously identified.

Distribution and fate of perfluoroalkyl substances in Mediterranean Spanish sewage treatment plants.

The concentrations of 21 perfluoroalkyl substances (PFASs: C4-C14, C16, C18 carboxylates, C4, C6-C8 and C10 sulfonates and C8 sulfonamide) were determined in influent, effluent and sludge from 16 different sewage treatment plants (STPs) located in the Ebro (6), Guadalquivir (5), Jucar (2) and Llobregat (3) Rivers, in two consecutive years (2010 and 2011). The analytes were extracted by solid phase extraction (SPE) and determined by Liquid Chromatography triple Quadrupole Mass Spectrometer (LC-QqQ-MS). All samples, except two sludges from Guadalquivir River STPs, were contaminated with at least one PFAS.

Patterns of presence and concentration of pesticides in fish and waters of the Júcar River (Eastern Spain).

The Júcar River, in a typical Mediterranean Basin, is expected to suffer a decline in water quality and quantity as a consequence of the climate change. This study is focused on the presence and distribution of pesticides in water and fish, using the first extensive optimization and application of the QuEChERS method to determine pesticides in freshwater fish. Majority pesticides in water - in terms of presence and concentration - were dichlofenthion, chlorfenvinphos, imazalil, pyriproxyfen and prochloraz (associated with a frequent use in farming activities), as well as buprofezin, chlorpyriphos and hexythiazox.

Occurrence and removal efficiency of pesticides in sewage treatment plants of four Mediterranean River Basins.

Removal of contaminants in the sewage treatment plants (STPs) can be incomplete causing their release to the environment. In this paper, the results of an extensive survey on more than 40 pesticides carried out in 2010 and 2011 in 16 STPs of Ebro, Guadalquivir, Jucar and Llobregat Rivers (Spain) are presented. In 2010, of 43 analytes screened, 29 were detected in influent and 28 in effluent samples, meanwhile in 2011, of 50 analytes, 33 and 34 were detected, respectively.

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

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.

Comparison of the effectiveness of recent extraction procedures for antibiotic residues in bovine muscle tissues.

Acetonitrile extraction followed by primary-secondary amine dispersive SPE cleanup QuEChERS (quick, easy, cheap, effective, rugged, and safe), was compared to pressurized liquid extraction (PLE) using water at 70 degrees C for 10 min at 1500 psi for the determination of 16 veterinary drugs in bovine muscle tissues by LC/MS/MS. PLE was significantly more effective for the extraction of veterinary drugs (ranging from 69 to 103% with RSD < or = 18%) than QuEChERS (ranging from 19 to 89% with RSD < or = 19%). Linearity of the calibration curves was obtained over the range considered from 10 microg/kg or LOQ to 1000, microg/kg) with r2 > or = 0.

Analysis of insecticides in honey by liquid chromatography-ion trap-mass spectrometry: comparison of different extraction procedures.

The feasibility of different extraction procedures was tested and compared for the determination of 12 organophosphorus and carbamates insecticides in honey samples. In this sense, once the samples were pre-treated - essentially dissolved in hot water by stirring - and before they could be analyzed by liquid chromatography-ion trap-second stage mass spectrometry (LC-MS(2)), four different approaches were studied for the extraction step: QuEChERS, solid-phase extraction (SPE), pressurized liquid extraction (PLE) and solid-phase microextraction (SPME). The main aim of this work was to maximise the sensitivity of pesticides and to minimise the presence of interfering compounds in the extract.