Environmental distribution of PAHs in pine needles, soils, and sediments.

Introduction: The content of 16 polycyclic aromatic hydrocarbons (PAHs) was determined in 60 samples from three environmental matrices (soils, sediments, and pine needles) in an effort to assess their distribution on a river basin scale.

Methods: A sampling campaign was carried out in 2006, selecting urban, industrial, and agricultural sampling sites along the northeast of Spain. Techniques used included pressurized liquid extraction and solid-liquid ultrasonic extraction followed by gas chromatography-electron impact ionization mass spectrometry.

Occurrence and fate of organochlorinated pesticides and PAH in agricultural soils from the Ebro River basin.

This study was aimed to assess the presence and fate of 22 organochlorinated pesticides (OCHs) and their degradation products and 16 Environmental Protection Agency-priority polycyclic aromatic hydrocarbons (PAHs) in soils of the Ebro River basin (NE Spain) during a 3-year period. The study site is characterized by a long and active agricultural history where pesticides have largely been used. Soils were extracted using pressurized liquid extraction followed by gas chromatography-mass spectrometry.

Development of a portable biosensor for screening neurotoxic agents in water samples.

A high sensitive portable biosensor system capable of determining the presence of neurotoxic agents in water has been developed. The system consists of (i) a screen-printed electrode with acetylcholinesterase (AChE) immobilized on it, (ii) a self-developed portable potentiostat with an analog to digital (A/D) converter and a serial interface for transferring data to a portable PC and (iii) an own designed software, developed with Lab-Windows CVI, used to record and process the measurements. The system has been developed to perform high precision amperometrical measurements with low drifts, low noise and a good reproducibility.

Impact of pesticides used in agriculture and vineyards to surface and groundwater quality (North Spain).

An environmental monitoring program was carried out to determine the impact of eight pesticides on the surface and groundwater quality of agricultural areas within the Ebro, Duero and Miño river basins. Three triazines and their desethyl degradation products, metolachlor and metalaxyl, were monitored during 18 months in 63 sites. Solid-phase extraction (SPE) using OASIS HLB 60 mg cartridges and gas chromatography-mass spectrometry (GC-EI-MS) provided good analytical quality parameters and limits of quantification of 0.

Priority pesticides and their degradation products in river sediments from Portugal.

A multiresidue gas chromatography-mass spectrometry method was developed to determine 28 priority pesticides of different chemical families (organochlorine, organophosphorus, triazines, anilides) together with some of their transformation products in river sediment. Ultrasonic, Soxhlet and pressurized liquid extraction (PLE) methods were compared in spiking experiments using acetone:hexane (1:1) followed by alumina solid phase extraction cartridges or in-cell alumina clean-up for PLE. All extraction techniques produced acceptable recoveries for the pesticides under study, although Soxhlet extraction produced the lowest recoveries for 2,4-DDE, trifluralin, lindane, and hexachlorobenzene (<50%) whereas ultrasonic extraction resulted in low recoveries for hexachlorobenzene and lindane (<50%).

Assessment of priority pesticides, degradation products, and pesticide adjuvants in groundwaters and top soils from agricultural areas of the Ebro river basin.

Gas chromatography-mass spectrometry (GC/MS) was employed for the determination of 30 widely used pesticides including various transformation products and alkylphenols in water and agricultural soils with the aim of assessing the impact of these compounds in agricultural soils and the underlying aquifer. The extraction, clean-up, and analytical procedures were optimized for both water and soil samples to provide a highly robust method capable of determining target analytes at the ppb-ppt level with high precision. For water samples, different solid-phase extraction cartridges and conditions were optimized; similarly, pressurized liquid extraction conditions were tested to provide interference-free extracts and high sensitivity.

Sampling of water, soil and sediment to trace organic pollutants at a river-basin scale.

Sampling is considered a crucial step in the analysis of organic compounds in the environment. This review describes field sampling techniques and provides detailed step-by-step procedures for collection and preservation of all major environmental matrices (water, sediment and soil) integrated as part of the river-basin water cycle. Attention is given to the prerequisites for obtaining reliable samples, and the practical issues of sample collection (planning, field sampling, sampling strategies and equipment and data quality assessment) are considered.