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Postigo C.,CSIC - Institute of Environmental Assessment And Water Research | Lopez de Alda M.J.,CSIC - Institute of Environmental Assessment And Water Research | Barcelo D.,CSIC - Institute of Environmental Assessment And Water Research | Barcelo D.,Catalan Institute for Water Research | And 3 more authors.
Journal of Hydrology | Year: 2010

The present work describes an automated methodology based on on-line solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry (on-line SPE-LC-ESI-MS/MS) for the determination of 22 medium to highly polar pesticides in groundwater, and its application to the analysis of 133 samples collected from different aquifers of Catalonia (NE Spain), in areas where agricultural practice is significant. Sample preconcentration was performed by passing 5 mL of the sample through PLRPs cartridges (for analysis of 16 pesticides measured in the positive ionization mode) and through Hysphere-Resin GP cartridges (for analysis of six pesticides measured in the negative ionization mode). Further LC-MS/MS determination was performed in the selected reaction monitoring (SRM) mode, by recording two SRM transitions per compound, thus obtaining four identification points. The methodology developed allows the determination of the target compounds at the pg or low ng L-1 level with satisfactory precision (relative standard deviations lower than 16%) and accuracy (recovery percentages higher than 75%) and is well suited for routine monitoring. Its application to various groundwater samples from Catalonia has revealed simazine, diuron and atrazine (present in more than 70% of the samples) as the most ubiquitous compounds. Approximately 16% of the samples investigated had individual pesticides levels above 100 ng L-1 and 7% presented total pesticides levels above 500 ng L-1. Concentrations higher than 100 ng L-1 were found for all triazines studied but cyanazine, the phenylureas diuron, linuron and chlortoluron, the target chloroacetanilides alachlor and metolachlor, and the organophosphate dimethoate in a few samples. Three and eight out of the 16 investigated groundwater bodies presented total pesticide levels exceeding the EU quality standards in terms of individual and total pesticide concentrations, 100 and 500 ng L-1, respectively. © 2009 Elsevier B.V. All rights reserved.


Flor-Arnau N.,University of Barcelona | Real M.,United Research Services Espana | Gonzalez G.,United Research Services Espana | Sanchez J.C.,University of Barcelona | And 3 more authors.
Limnetica | Year: 2015

The Water Framework Directive (WFD) implementation requires the use of biological quality elements to assess ecological status in water bodies, including aquatic flora. Previous macrophyte indices have been developed for rivers in several Mediterranean regions of the Iberian peninsula. Due to the lack of a suitable tool that would consider macrophyte and physicochemical characteristics of all Spanish Mediterranean fluvial types, the Fluvial Macrophyte Index (IMF) was designed in compliance with WFD. We have worked with the identified samples collected from 177 sites and with the data from 121 extra sites from projects carried out in the Ebro basin and in Catalonia. IMF includes tolerance values and ecological range of 124 taxa (50 angiosperms, 31 alg, 30 mosses, 8 liverworts and 5 pteridophytes). IMF scores are obtained from the Zelinka and Marvan's (1961) formula and the value is then assigned to the corresponding quality class according to the WFD. This assignment is based on the fluvial group to whom the sampling site corresponds. Each group includes several Mediterranean river types based on their similarity of macrophyte inventories and for each of them the reference values and thresholds between quality classes have been calculated. The IMF has been correlated with other macrophyte indices, as well as with hydromorphological indices and physicochemical variables. Most of the correlations are significant and the obtained coefficients are high. In addition, the IMF is able to statistically discriminate reference sites from perturbed sites in most of the fluvial groups. Moreover, if the indices contained in the Water Planning Instruction (Ministerial Order ARM/2656/2008, 10 September) are applied, the IMF shows a high discrimination efficiency between sites with good or higher ecological status and the rest. Therefore, the IMF is proposed as an effective ecological tool to assess the ecological status of Mediterranean rivers. © Asociación Ibérica de Limnología Madrid.

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