E. Beceiro-González

Metals in airborne particulate matter in La Coruña (NW Spain)

Abstract A study of heavy metal (Pb, Cd, Mn, V, Zn and Fe) concentrations in atmospheric particulate by sampling particulate matter is described at two different locations in La Coruna (NW Spain), using high volume samplers equipped with glass microfiber filters. Filters were subjected to an acidic extraction. Heavy metal determination was performed by means of atomic absorption spectroscopy with electrothermal atomization for Pb, Mn, Cd and V, with an air-acetylene flame for Fe, Zn and Cu. Principal components analysis suggest two main sources of elements: anthropogenic and soil crosion patterns. Results showed that the particulate matter concentration depends on atmospheric conditions.

Development of a Matrix Solid Phase Dispersion methodology for the determination of triazine herbicides in mussels

A method based on Matrix Solid Phase Dispersion (MSPD) for determination of nine triazines in mussels has been optimised in terms of the sorbents used for extracting and cleaning-up. Two dispersing agents: C18 and florisil, and eight cleanup co-sorbents: florisil, silica, silica/alumina, Envi™ Carb, Envi-Carb-II/PSA, SAX/PSA, Envi-Carb-II /SAX/PSA and C18 were assayed. Analytes were eluted using 20 mL of ethyl acetate and 5 mL of acetonitrile and finally the extract was concentrated to dryness, re-constituted with 1 mL methanol and determined by HPLC-DAD. The best results were obtained with C18 as dispersing agent and Envi-Carb-II/SAX/PSA as clean-up co-column. Recoveries ranged between 79% and 99% and repeatability and reproducibility were below than 16% for all compounds. The linearity of the calibration curves yielded the R(2)⩾0.9993. The LOQ values ranged from 0.10 to 0.18 mg kg(-1) dried sample. Finally the method was applied to the analysis of mussel samples from Galicia (NW Spain).

Total arsenic and selenium levels in atmospheric particulate matter of La Coruña (Spain)

This paper presents a study concerning the degree of pollution due to arsenic and selenium in atmospheric particulates of La Coruña (NW Spain). Sampling of particulate matter was accomplished with high volume samplers equipped with glass microfibre filters; samples were collected in two different areas (one an industrial area and the other a rural area). For As and Se determination, hydride generation and electrothermal atomization atomic absorption spectrometry, respectively, were used.

On-line solid-phase extraction method for determination of triazine herbicides and degradation products in seawater by ultra-pressure liquid chromatography-tandem mass spectrometry.

A fast, simple, selective and sensitive method has been developed for the determination of nine triazine herbicides (ametryn, atrazine, cyanazine, prometryn, propazine, simazine, simetryn, terbuthylazine and terbutryn) and eight degradation products (desethyl atrazine, desethyl-desisopropyl atrazine, desethyl 2-hydroxyatrazine, desethyl terbuthylazine, desisopropyl atrazine, desisopropyl 2-hydroxyatrazine, 2-hydroxyatrazine and 2-hidroxyterbuthylazine) in seawater samples. On-line solid-phase extraction coupled with ultra-pressure liquid chromatography-tandem mass spectrometry was employed for simultaneous analysis of all compounds in 11min. Validation parameters were studied through the estimation of the limits of detection and quantification, calibration curves and precision. Limits of quantification ranged from 0.023 to 0.657μgL-1. Good linearity was obtained for all compounds with R2>0.99 in all cases. Furthermore, inter-day precision (0-2.1%) and intra-day precision (0-3.9%) were shown to be satisfactory. On-line solid-phase extraction recoveries in spiked unpolluted seawater sample were evaluated and acceptable values (80.3-99.8%) with adequate RSD (0.1-3.1%) were found. Finally, the proposed method was applied to the analysis of the target compounds in seawater samples collected from seawater nearby a zone of intensive horticulture of Matosinhos (Portugal). The concentrations of the herbicides were below the limit of detection in all cases.

A simple method for simultaneous determination of nine triazines in drinking water

A simple, effective, and economic method for determination of nine triazines (ametryn, atrazine, cyanazine, prometryn, propazine, simazine, simetryn, terbuthylazine, and terbutryn) in drinking water based on solid-phase extraction (SPE) followed by high-performance liquid chromatography-diode array detection (HPLC-DAD) was developed. A specialized solid phase (Oasis HLB) was used, and the parameters that may affect the efficiency of SPE were optimized. The limits of detection (ranged from 0.010 to 0.023 µg L−1) were satisfactory and allow the determination of triazines at the levels required by European Union legislation. Repeatability (2.4–7.6%) and intermediate precision (0.9–11.0%) calculated at 0.1 µg L−1 (legislation level) were adequate. The accuracy calculated as the average recovery of spiked tap and mineral waters was higher than 86% for all compounds. The developed method also could be used for undergraduate laboratory experiments because it acquaints students with solution preparation, solid phase extraction procedure, and HPLC-DAD technique.

Application of a Developed Method for the Extraction of Triazines in Surface Waters and Storage Prior to Analysis to Seawaters of Galicia (Northwest Spain)

A simple method based on solid-phase extraction combined with liquid chromatography for simultaneous determination of nine triazine herbicides (ametryn, atrazine, cyanazine, prometryn, propazine, simazine, simetryn, terbuthylazine, and terbutryn) in surface water samples was developed and validated. Under optimized conditions, 50 mL of water sample was pumped through the Oasis HLB cartridge, and triazines were eluted with 3 mL acetone. Finally the extract was concentrated to dryness, reconstituted with 1 mL methanol : water (1 : 1) and injected into the HPLC-DAD system. The stability of the herbicides on the cartridges at −18 and 4°C was also evaluated, and the recoveries obtained after three weeks of storage were satisfactory for all compounds. The analytical features of the proposed method were satisfactory: repeatability and intermediate precision were <10% and recoveries in spiked river water and seawater samples were higher than 93% for all compounds studied. Limits of quantification (varied from 0.46 to 0.98 µg L−1) were adequately allowing the determination of these compounds at the levels requested by the 2008/105/EC Directive. Finally, this method was applied to the analysis of 50 seawater samples from Galicia (northwest Spain).