Analytical study on ethephon residue determination in water by ion-pairing liquid chromatography/tandem mass spectrometry

A detailed analytical study on ethephon residue determination in water, making use of ion-pairing liquid chromatography coupled to electrospray tandem mass spectrometry (LC/MS/MS), has been carried out. Ethephon is a plant growth regulator, highly polar, which is typically present in aqueous solution in anionic form due to its acid character. Both its extraction and pre-concentration from water samples and its chromatographic retention are difficult. Several approaches for sample pretreatment have been tested including direct injection into the chromatographic system, on-line solid phase extraction (SPE) and off-line SPE, with the best results being obtained after off-line SPE, using Oasis MAX cartridges (mixed-mode strong anion-exchange). After testing several ion-pairing reagents, tetrabuthylammonium acetate (TBA) was selected. This was added to the samples before LC/MS/MS analysis to facilitate ethephon chromatographic retention. The acquisition of several specific MS/MS transitions together with the evaluation of their relative intensity ratios allowed the reliable confirmation of the analyte in samples. The optimised approach was tested in low-salinity water spiked at 0.1 µg L−1 level with satisfactory recovery, and a limit of detection of 0.02 µg L−1. To this purpose, the water sample was partially de-ionised in an initial stage, in order to remove major ions that would have interfered in analyses. The application of this methodology to more saline/complex water samples, as surface or wastewater, was problematic and a thorough optimisation of the de-ionisation conditions would be required

Analytical strategy based on the use of liquid chromatography and gas chromatography with triple-quadrupole and time-of-flight MS analyzers for investigating organic contaminants in wastewater

The presence of a wide variety of organic pollutants with different physico-chemical characteristics has been investigated in wastewater samples from a municipal solid waste treatment plant placed at Castellón, Spain. An advanced analytical strategy has been applied, consisting on the combined used of two powerful and complementary techniques, GC and LC, both hyphenated with tandem mass spectrometry with triple quadrupole analyzers. The GC-MS/MS method was based on sample extraction using C18 SPE cartridges and allowed the determination of around 60 compounds from different chemical families, such as PAHs, octyl/nonyl phenols, PCBs, organochlorine compounds, insecticides, herbicides and PBDEs. Most of compounds selected are included as priority contaminants in the European Union (EU) Water Directive. The UHPLC-MS/MS method, which provided high chromatographic resolution and sensitivity and short analysis time, used a sample extraction with OASIS HLB SPE cartridges and allowed the determination of 37 (more polar) pesticides. The methodology developed has been applied to the analysis of 41 water samples (20 non-treated, raw leachates, and 21 treated) collected between March 2007 and February 2009. Treated (reverse osmosis) water samples analyzed rarely exceeded 0.5 μg/L for the contaminants investigated. As expected, in non-treated leachates the number of detections and the concentration levels found were notably higher than in treated waters. The most commonly detected pollutants were herbicides (simazine, terbuthylazine, terbutryn, terbumeton, terbacil and diuron), together with fungicides (thiabendazole and carbendazim) and 4-t-octylphenol. In the light of data obtained, it has been proven that reverse osmosis process used for water treatment was efficient and notably reduced the levels of organic contaminants found in raw leachate samples. 2 In order to investigate the presence of other non-target contaminants, water samples were also analyzed by using GC-TOF MS and LC-QTOF MS. Several organic pollutants that did not form a part of the previous list of target contaminants were identified in the samples, thanks to the good sensitivity of TOF MS in full spectrum acquisition mode and the valuable accurate mass information provided by these instruments. The insecticide diazinon, the fungicide diphenylamide, the UV filter benzophenone, N-butyl benzenesulfonamide (N-BBSA), the insect repellent diethyltoluamide, caffeine or pharmaceuticals like erythromycin, benzenesulfonanilide, ibruprofen, atenolol or paracetamol, were some of the compounds identified in the water samples analyzed

Determination of free amino acids in plants by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS)

A robust and sensitive method for identification (quantification and confirmation) of 19 free amino acids in the plant matrix, Stellaria media, based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS), with a triple quadrupole analyser, has been developed. Regarding MS optimization, flow injection analysis (FIA) was used in scan and selected reaction monitoring (SRM) mode. The collision energies optimized varied from −12 to −39 eV. The acquisition of three MS/MS transitions for most of the compounds allowed the accurate confirmation of these analytes, which was supported by the accomplishment of ion intensity ratios and retention time as compared with the corresponding standards. The use of a Phenomenex EZ:faast™ Free (Physiological) Amino Acid kit speeds up the sample preparation immeasurably. Nineteen amino acids were separated within 18 minutes on a reverse-phase column under a gradient stepwise programme using 10 mM ammonium formate both in water and methanol. The detection limit (LOD) for free amino acids varied from 0.4 to 9.1 pmol mL−1, except for asparagine amounting to 3000 pmol mL−1. The quantification precision (RSD) of free amino acids for intra- and interday assays was 0.05–19% and 0.2–19%, respectively, but for most of the compounds, it did not exceed 5%. The optimized and validated method was subsequently utilized for free amino acid identification in weed collected from field locations in Poland.National Science Centre: UMO-2013/09/N/NZ9/0196

Simultaneous determination of triazines and their main transformation products in surface and urban wastewater by ultra-high-pressure liquid chromatography- tandem mass spectrometry

This work describes the optimization, validation and application to real samples of an ultra-high-pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the quantification and confirmation of 11 compounds (atrazine, simazine, terbuthylazine, terbumeton, terbutryn and their main transformation products) in surface and wastewater samples. Most of these analytes are included in the list of priority substances in the framework on European Water Policy. The application of this method to water samples reveals that the most relevant transformation products (TPs) should be incorporated into current analytical methods (which are focused mainly on the determination of unchanged compounds), to obtain a more realistic knowledge on water quality regarding pesticide contamination. TPs are generally more polar and mobile than the parents and they can be transported to the aquatic environment more rapidly than their precursors. Additionally, they can present some degree of toxicity and in fact TPs are also included within the legislation on drinking water as pesticide derivatives. To efficiently combine UHPLC with MS/MS, a fast-acquisition triple quadrupole mass analyzer was used. Working in selected reaction monitoring mode, up to three simultaneous transitions per compound were acquired allowing a reliable identification at ng/L levels. The method developed includes a pre-concentration step based on solid-phase extraction (OASIS HLB cartridges). Satisfactory recoveries (70-120%) and relative standard deviations (<20%) were obtained for all compounds in different water samples types spiked at two concentration levels (0.025 and 0.1 μg/L). The optimized method was found to have excellent sensitivity with instrumental detection limits as low as 50 fg. In addition, the influences of the matrix constituents on ionization efficiency and extraction recovery have been studied in different types of Italian and Spanish surface and urban wastewater. Signal suppressions were observed for all compounds, especially for influent wastewater. The use of isotope-labelled internal standards was found to be the best approach to assure an accurate quantification in all matrix sample

Pesticide residues and transformation products in groundwater from a Spanish agricultural region on the Mediterranean Coast

An overview is given on the presence and changes over time of pesticide residues in groundwater from the Valencia region, one of the most important citrus cultivation sites of southern Europe. A multiresidue LC-MS/MS method was applied for the screening of around 50 pesticides in 75 water samples collected during 2000. The herbicides simazine, terbuthylazine, bromacil, terbumeton, and diuron were the most frequently detected compounds. On the basis of compounds detected in these samples, another method that focused on 30 herbicides and relevant transformation products (TPs) was developed and applied to around 80 water samples collected during 2003. Simazine was the most frequently found compound followed by several triazine metabolites. Data for this paper show the vulnerability of groundwater in this area to herbicide applications and illustrate the importance of including pesticide TPs in environmental monitoring programmes, as four out of the five compounds most frequently detected were pesticide TP

Removal efficiency for emerging contaminants in a WWTP from Madrid (Spain) after secondary and tertiary treatment and environmental impact on the Manzanares River

The effluents from wastewater treatment plants (WWTPs) can be an important contamination source for receiving waters. In this work, a comprehensive study on the impact of a WWTP from Madrid on the aquatic environment has been performed, including a wide number of pharmaceuticals and pesticides, among them those included in the European Watch List. 24-h composite samples of influent (IWW) and effluent wastewater after secondary (EWW2) and after secondary + tertiary treatment (EWW3) were monitored along two campaigns. Average weekly concentrations in IWW and EWW2 and EWW3 allowed estimating the removal efficiency of the WWTP for pharmaceutical active substances (PhACs). In addition, the impact of EWW3 on the water quality of the Manzanares River was assessed, in terms of PhAC and pesticide concentrations, through analysis of the river water collected upstream and downstream of the discharge point. After a preliminary risk assessment, a detailed evaluation of the impact on the aquatic environment, including a toxicological study and screening of pharmaceutical metabolites, was made for the seven most relevant PhACs: sulfamethoxazole, azithromycin and clarithromycin (antibiotics), metoprolol (antihypertensive), diclofenac (anti-inflammatory/analgesic), irbesartan (antihypertensive), and the antidepressant venlafaxine. Among selected PhACs, irbesartan, clarithromycin and venlafaxine presented moderate or high risk in the river water downstream of the discharge. Albeit no acute toxicity was detected, more detailed studies should be carried out for these substances, including additional toxicological studies, to set up potential sublethal and chronic effects on aquatic organisms.Funding for open access charge: CRUE-Universitat Jaume

The Chub Mackerel (Scomber Colias) in the Atlantic Spanish Waters (ICES Divisions 8.c and 9.a): Biological, fishery and survey data

Atlantic chub mackerel (Scomber colias , Gmelin, 1978) is a middle-sized pelagic fish distributed in warm and temperate Northeast Atlantic waters. The bulk of the catches takes place in north western waters of Africa, but landing are significantly increased in the most recent years in the Iberian Peninsula, resulting a new target species for both Portuguese and Spanish purse seiner fleets which partially replaces the important drop of sardine landings in both countries. Given this increasing importance and the lack, for the time being, of any scientific assessment, nor management plan and in order to update the available biological and catch information on this specie in Spanish Atlantic waters, this paper working document compile, review and analyze the existing data of biology, fisheries, and surveys to further enhance knowledge on chub mackerel in Atlantic Iberian waters (ICES Subdivisions 9.a South & North and Division 8.c), specifically: (i) stock structure, (ii) spatial distribution (iii) growth and reproduction and (iv) fisheries exploitation. This analysis suggests an increasing trend in Atlantic waters (9a) in both spatial distribution and abundance, mainly due to the strength of the 2015 and 2016 cohorts. This area, besides, could be considered as a nursery area while the Cantabrian Sea (8c) is rather main spawning area. The increase of such availability is also discussed within the frame of the North East Atlantic warming

Participación y diversidad. Avanzando en la participación de las personas inmigrantes en la sociedad civil de Andalucía. Libro del proyecto y transcripción de las sesiones

Hasta el momento actual, la Inmigración ha venido abordándose bajo un enfoque estrictamente laboral o administrativo, fundamentado en los flujos que el mercado de trabajo demandaba. En menor medida desde la perspectiva del ejercicio de la ciudadanía de las personas inmigrantes, que han venido a buscar una nueva vida en Andalucía, ni en la consideración de que, además, ello le supone ejercer derechos básicos y contribuir a enriquecer y dar nuevas perspectivas y valores a nuestra sociedad civil. Desde este enfoque, el capital social que supone la Inmigración resulta necesario e imprescindible en los procesos de participación y empoderamiento de la sociedad civil de nuestra democracia. Para determinar una estrategia y encontrar las herramientas más adecuadas que nos permitan avanzar en este sentido, es para lo que hemos impulsado el proyecto "Participación y Diversidad" y los dos foros de indagación y debate participativo, que se han celebrado en Sevilla y en Granada entre octubre y noviembre de 2013 y cuyos resultados tienen ustedes en este libro. Por lo general, las personas inmigrantes sólo son llamadas a participar de los asuntos públicos cuando éstos tienen que ver con el tema específico de la inmigración. Pero, en este caso, hemos querido ir más allá abordando la cuestión de la inmigración no en términos particulares sino en relación con su papel en el conjunto de nuestra sociedad, en el procomún; trabajando sobre ese capital social que aportan y sobre el papel ciudadano que desempeñan -o que queremos que aporten y desempeñen las personas inmigrantes. En definitiva, trabajar sobre la participación real y efectiva en nuestra sociedad civil, de las personas que vienen de otros países (de la UE, países desarrollados o en vías de desarrollo) y con otras visiones del mundo, a compartir espacio y vida con nosotros, en igualdad con los andaluces y las andaluzas de origen.Pp. (1-129

Perception of Spanish medical students with regard to working abroad. The role of the university and scientific conferences

Objetivos: Los estudiantes de medicina de las universidades españolas que muestran interés por la investigación tienden a querer desarrollar su carrera en el extranjero o a percibir que en otros países es más sencillo investigar que en España. El objetivo de nuestro estudio es evaluar aquellos parámetros que influyen en esta percepción. Métodos: Realizamos una encuesta con 15 ítems, recogiendo la “experiencia en investigación”, “opinión sobre el papel de la universidad e instituciones”, “interés y conocimiento en investigación”, “percepción sobre emigrar al extranjero” y “opinión acerca de los congresos científicos de estudiantes”, que fue rellenada por 288 estudiantes de diversas facultades de medicina de España. Realizamos un análisis estadístico mediante tests de correlación de Pearson y test T de Student. Resultados: Los principales resultados de nuestro estudio muestran que los estudiantes con mayor interés y conocimiento en investigación poseen una mayor predisposición a emigrar al extranjero. Asimismo, estos estudiantes tienen una peor opinión acerca de las facilidades que la universidad y entidades públicas destinan en España a ello, teniendo sin embargo una mejor opinión sobre la utilidad de los congresos científicos y experiencias de investigación activas en el extranjero. Conclusiones: Nuestro estudio sugiere que las universidades españolas deberían centrar sus esfuerzos en ofrecer a los estudiantes de medicina posibilidades para iniciarse de manera activa y útil en la investigación. Congresos científicos de estudiantes, así como programas universitarios de acceso a la investigación parecen ser las opciones preferidas para evitar esta migración de los talentos científicos médicos de nuestro país.Objectives: Medical students interested in research tend to show a greater predisposition on developing their professional career abroad. They also perceive that developing research in other countries is easier than in Spain. This study is aimed at assessing the parameters that affect this perception. Methods: 288 students from various Spanish medical schools completed a questionnaire consisting of 15 questions. This questionnaire assessed “experience in research”, “opinion on the university role in research initiation”, “interest in and knowledge on scientific research”, “perception of emigrating abroad”, and “opinion on scientific conferences for students”. Pearson correlation analysis and Student’s t-tests were applied. Results: Students with greater interest in and knowledge on research presented an increased predisposition on studying abroad and showed a negative opinion on the facilities provided by the Universities and public institutions in Spain. In contrast, they think that scientific conferences are useful and have a good opinion on active research experiences abroad. Conclusions: Our study suggests that Spanish Universities should concentrate their efforts in order to introduce Medical students to research in an active and useful manner. Scientific conferences for students as well as research access programmes seem to be the preferred options to avoid the emigration of Spanish scientific talents