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Chile is one of the major producers of phytocolloids extracted from seaweed. Multicellular algae are considered to be primary accumulators of arsenic. We analyzed 14 species of algae belonging to the groups Rhodophyceae (10), Phaeophyceae (3) and Chlorophyceae (1) from different coastal zones of Chile in 2003-2004. Dry ashing mineralization (for total As) and acid digestion (for inorganic As) together with quantification by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) were employed. In general, total arsenic concentrations varied between 3.0 and 68mgkg -1, whereas inorganic arsenic concentrations ranged between 0.15 and 1.06mgkg -1. The algal species Durvillaea antarctica and Porphyra columbina, used for direct human consumption, did not have inorganic arsenic levels that represent a health risk to consumers. Among species used for phytocolloids production, such as Macrocystis piryfera, Gracilaria chilensis and Gigartina skottsbergii, observed levels of inorganic arsenic were greater than 1mgkg -1, the limit value established by the regulations of some countries. Among the 14 species of algae tested, inorganic arsenic levels were between 0.8% and 13% of the total arsenic concentrations; that is, arsenic present in these algae was found primarily as organic arsenic.

A column-switching system between a cation-exchange column (PRP-X200) and an anion-exchange column (PRP-X100) was used for separation of eight arsenic species. The sample was injected on the PRP-X200 column and the species eluted in the void volume of that column [arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine (AB)] were transferred to the PRP-X100 column and, after separation, were thermo-oxidized on-line and detected by hydride generation (HG) atomic absorption spectrometry (AAS). The species initially retained in the PRP-X200 column were subsequently separated in that column, thermo-oxidized on-line and detected by HG atomic fluorescence spectrometry (AFS). The organoarsenical species present in natural seafood products were extracted with methanol-water and quantified using the proposed method. The analytical features of the method are reported. The highest limit of detection (LOD) for the sample was obtained for AB [3.6 ng g-1, dry mass (dm)], whereas TMAO and DMA gave the lowest LOD (0.9 ng g-1 dm). For all species the methodology developed provides optimum precision, ranging from 1 to 12%, and the recovery percentage was greater than 95% for all species. The method was applied to the following certified reference materials: CRM 627 (Tuna fish tissue, Institute for Reference Materials and Measurements, IRMM), DORM-2 (Dogfish muscle, National Research Council of Canada, NRCC), TORT-2 (Lobster hepatopancreas, NRCC) and NFA-Shrimp and NFA-Plaice (National Food Agency of Denmark). Only CRM 627 is certified for arsenic species (AB and DMA), and the contents obtained for these species were compared with the certified values. The contents of the other arsenic species present in CRM 627 and the species in the other reference materials were compared with the data reported by other authors.

Se ha planteado como objetivo general de esta investigación el desarrollo de metodologias analiticas para la determinación de arsénico inorgánico en un amplio muestrario de productos pesqueros. Los resultados se evaluaron desde el punto de vista medio-ambiental sanitario y toxicologico. Para el cumplimiento de este objetivo general se han desarrollado metodologias para la determinacion de arsenico inorganico en aguas y productos pesqueros. Dichas metodologias se han aplicado a un amplio muestrario de productos pesqueros del Estuario Guadalquivir y de productos de la pesca pertenecientes a un estudio de dieta total. Los resultados obtenidos han permitido ponen de manifiesto la necesidad de regular los contenidos de arsenico en productos de la pesca en función de sus contenidos de arsenico inorganico.

To evaluate the impact on fauna of the release of toxic waste from the tailings dam operated by the Boliden Apirsa S.L company at Aznalcollar, Seville (Spain) a study was carried out of total and inorganic arsenic contents in 164 samples from six different estuary species, including molluscs, crustaceans and fish, collected at six sampling stations distributed along the estuary and mouth of the River Guadalquivir. The contents found, expressed in micrograms per gram wet weight, were as follows. Total arsenic: Crassostrea angulata - giant cupped oyster (2.44±0.45); Scrobicularia plana - peppery furrow (2.50±0.73); Palaemon longirostris - delta prawn (1.33±0.54); Uca tangeri - AfroEuropean fiddler crab (1.76±0.08); Melicertus kerathurus - shrimp (3.60±1.92); and Liza ramada - mullet (0.65±0.38). Inorganic arsenic: C. angulata (0.09±0.02); S. plana (0.38±0.23); P. longirostris (0.04±0.01); U. tangeri (0.22±0.03); M. kerathurus (0.03±0.01); and L. ramada (0.03±0.03). The levels of total As are comparable to those obtained by other authors. With respect to inorganic arsenic, only S. plana and U. tangeri present high levels of inorganic arsenic. This may be due to the fact that these organisms live in estuary sediments, reservoirs of inorganic arsenic, and ingest particles of sediments during feeding. Because of the lack of information for this area concerning previous levels of total and inorganic arsenic in the species analysed, it was not possible to establish the impact on the fauna of the River Guadalquivir estuary of the toxic spill resulting from the failure of the mine tailings dam at Aznalcollar. With respect to the implications to human health as a result of consumption of species from the Guadalquivir estuary, only with the species Scrobicularia plana, as a high consumption of this mollusc might, in some cases, exceed the maximum tolerable intake for inorganic arsenic indicated by the FAO/WHO. Consumption of the liver of L. ramada does not appear to present pro

A method for the selective quantitative determination of inorganic arsenic [As(III) + As(v)] in seafood was developed. In order to do so, various procedures for the solubilization and extraction of inorganic arsenic quoted in the literature were tested. None provided satisfactory recoveries for As(III) and As(v) in real samples. Consequently, a methodology was developed which included solubilization with HCl and subsequent extraction with chloroform. The arsenic was solubilized in 9 mol l-1 hydrochloric acid. After reduction by hydrobromic acid and hydrazine sulfate, the inorganic arsenic was extracted into chloroform, back-extracted into 1 mol l-1 HCl, dry-ashed, and quantified by hydride generation-atomic absorption spectrometry (HG-AAS). The analytical features of the method are as follows: detection limit, 3.07 ng g-1. As (fresh mass); precision (RSD), 4.0%; recovery, As(III) 99%. As(v) 96%. In the optimized conditions, other arsenic species - dimethylarsinic acid (DMA), arsenobetaine (AB), arsenocholine (AC) and tetramethylarsonium-ion (TMA+) - were not co-extracted. However, different percentages of minor species were extracted with chloroform: monomethylarsonic acid (MMA) 100%, and trimethylarsine oxide (TMAO) 3-10%. Real samples and reference materials of seafood (DORM-1, DORM-2, TORT-2, CRM-278 and SRM-1566a) were analyzed. The analysis of DORM-1 provided an inorganic arsenic value of 124 ± 4 ng g-1 As, dry mass (dm), which is very close to the value obtained by other authors using high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and ionic chromatography-hydride generation-atomic absorption spectrometry (IC-HG-AAS).

A long-term monitoring plan was established to study if bird populations around Donana National Park were affected by the toxic spill from the Aznalcollar mine. The concentrations of Zn, Pb, As, Cu, Sb, Co, Tl and Cd in the blood of 11 bird species feeding in the area were determined. The parameters which most affect the accumulation of trace elements in the birds studied are, firstly, species and, secondly, trophic position, sex, days of exposure and weight. In some individuals, Zn and Cu occurred at higher levels than the reference values for contaminated areas. Concentrations of Pb and Cd in a considerable number of individuals were higher than those found in birds from uncontaminated areas. The present data, together with the lack of data on blood metal concentration prior to the spill, do not offer any conclusive evidence of the influence of the spill on avian blood metal concentrations.

A method for the selective quantitative determination of inorganic arsenic [As(III) + As(v)] in seafood was developed. In order to do so, various procedures for the solubilization and extraction of inorganic arsenic quoted in the literature were tested. None provided satisfactory recoveries for As(III) and As(v) in real samples. Consequently, a methodology was developed which included solubilization with HCl and subsequent extraction with chloroform. The arsenic was solubilized in 9 mol 1(-1) hydrochloric acid. After reduction by hydrobromic acid and hydrazine sulfate, the inorganic arsenic was extracted into chloroform, back-extracted into 1 mol 1(-1) HCl, dry-ashed, and quantified by hydride generation-atomic absorption spectrometry (HG-AAS). The analytical features of the method are as follows: detection limit, 3.07 ng g(-1) As (fresh mass); precision (RSD), 4.0%; recovery, As(III) 99%, As(v) 96%. In the optimized conditions, other arsenic species-dimethylarsinic acid (DMA), arsenobetaine (AB), arsenocholine (AC) and tetramethylarsonium-ion (TMA(+))-were not co-extracted. However, different percentages of minor species were extracted with chloroform: monomethylarsonic acid (MMA) 100%, and trimethylarsine oxide (TMAO) 3-10%. Real samples and reference materials of seafood (DORM-1, DORM-2, TORT-2, CRM-278 and SRM-1566a) were analyzed. The analysis of DORM-1 provided an inorganic arsenic value of 124 +/- 4 ng g(-1) As, dry mass (dm), which is very close to the value obtained by other authors using high performance liquid chromatography -inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and ionic chromatography-hydride generation-atomic absorption spectrometry (IC-HG -AAS).