Lipid and fatty acid composition, and persistent organic pollutant levels in tissues of migrating Atlantic bluefin tuna (Thunnus thynnus, L.) broodstock

Lipid class, fatty acid and POP levels were measured in migrating Atlantic bluefin tuna (ABT) tissues caught off the Barbate coast, Spain. Tissue lipids were largely characterized by triacylglycerol, reflecting large energy reserves accumulated prior to reproductive migration. Fatty acid compositions of muscle, liver and adipose exhibited similar profiles, whereas gonads showed a higher affinity for docosahex- aenoic acid. Tissue POP concentrations correlated positively with percentage triacylglycerol and nega- tively with polar lipids. Highest POP concentrations were in adipose and lowest in gonads, reflecting lipid content. DL-PCBs contributed most to total PCDD/F þ DL-PCB levels, with mono-ortho concentrations higher in tissues, whereas non-ortho PCBs contributed greater WHO-TEQs due to differences in TEFs. PBDE47 was the most prominent BDE congener in tissues, probably through biotransformation of BDE99 and other higher brominated congeners. The perceived POP risk from ABT consumption should be balanced by the well-established beneficial effects on human health of omega-3 fatty acids

Comprehensive two-dimensional gas chromatography for the analysis and fast screening of polycyclic aromatic hydrocarbons in sediments

Trabajo presentado en el 36th International Symposium on Capillary Chromatography (ISCC), celebrado en Riva del Garda (Italia) del 27 de mayo al 1 de junio de 2012.This study evaluates the feasibility of comprehensive two-dimensional gas chromatography- time-of-flight mass spectrometry (GC×GC–ToF MS) for the determination of the 15+1 priority EU polycyclic aromatic hydrocarbons (PAHs) in sediments from the Sancti-Petri Channel (Cadiz Bay, Spain). The study area is a tidal channel of about 18 km, which connects the southern part of the Bay of Cádiz with the Atlantic Ocean. This protected natural enclave is potentially affected by different human and industrial activities. Firstly, standard solutions were used to optimise the separation by GC×GC–ToF MS of the investigated PAHs. Special attention was paid to critical PAH groups usually affected by chromatographic co-elution. The performance of the proposed methodology for the determination of the target compounds in real-life samples was evaluated by the analysis of sediment extracts prepared using a previously optimised microwave-assisted extraction-based method followed by solid-phase extraction purification. The developed methodology was then applied to the analysis of the 16 test PAHs in 17 sediments sampled along the 18-Km channel. The influence of the different industrial and human activities developed in the study area became evident though both, the detected PAH levels, and the divergent profiles observed for the compounds in the analysed sediments. Regarding this last aspect, the feasibility of a visualisation approach based on the use of size-normalised bubbles for the fast screening of PAH occurrence and the tentative identification of the potential major pollution sources was evaluated.Authors thank projects CTQ-2006-14993/BQU, AGL2009-11909 and S-2009/AGR-1464 for financial support.Peer Reviewe

Anthropogenic and naturally-produced organobrominated compounds in bluefin tuna from the Mediterranean Sea

Anthropogenic compounds, such as polybrominated diphenyl ethers (PBDEs), together with naturally-produced organobromines, such as methoxylated PBDEs (MeO-PBDEs), polybrominated hexahydroxanthene derivates (PBHDs), 2,4,6-tribromoanisole (TBA) and a mixed halogenated monoterpene (MHC-1), were measured in muscle from 26 farmed and wild bluefin tuna (Thunnus thynnus) caught in the Mediterranean Sea. This species is ecological attractive because of the changes of geographic habitat throughout its long lifespan which affect its feeding and because it is a part of human diet (especially for people living on coastal areas). PBDE concentrations were similar between tuna samples of different groups (17-149 ng/g lw in farmed tuna, 25-219 ng/g lw in longline-fished tuna and 26-126 ng/g lw in net-fished tuna). However, higher concentrations of naturally-produced MeO-PBDEs and PBHDs were observed in the two types of wild tuna (longline-fished and net-fished) compared to farmed tuna suggesting that wild tunas come easily in contact with sources of these compounds. In all cases, PBHDs presented the highest contribution to the sum of organobromines (50% in farmed tuna and > 90% in wild tuna). TBA was detected at low concentrations (< 6 ng/g lw), while MHC-1 was found at higher levels (up to 42 ng/g lw) in farmed tuna. The estimated daily ingestion of PBDEs from tuna was 830 ng PBDEs/day, regardless of the origin of the tuna. While this value is approximately 600 times lower that the minimum risk level set by the U.S. Department of Health and Human Services, it is approximately 8 times higher than the total intake of PBDEs via diet, suggesting that consumption of tuna can add considerably to the total daily intake of PBDEs

Zebrafish (<i>Danio rerio</i>) Eleutheroembryo-Based Procedure for Assessing Bioaccumulation

This paper reports on the development and preliminary evaluation of a new bioaccumulation test based on the use of zebrafish <i>(Danio renio)</i> eleutheroembryos (72 h after hatching, corresponding to 144 h post fertilization, hpf) as an alternative to adult fish-based procedures for regulatory purposes regarding REACH application. The proposed test accomplished the OECD 305 guideline and consists of a 48 h uptake period followed by a 24 h depuration step. Bioaccumulation experiments were performed for a selected of hyper hydrophobic chemicals (log <i>K</i>_ow> 7.6), that is, PCB 136 and PBDE 154 at two concentration levels corresponding roughly to 1% and 0.1% the chemicaĺs LC₅₀(nominal concentrations of 4.0 and 12.0 μg/L for PCB 136, and 1.0 and 5.0 μg/L PBDE 154, respectively). Toxicokinetic models were used to calculate the bioconcentration factors (BCFs) based on of the chemical concentrations found in the contaminated eleutheroembryos and their surrounding media. The experimentally determined accumulation profiles show bioaccumulation by zebrafish eleutheroembryos of both chemicals, and that the process is more complex than simple water–lipid partition. Calculated log BCFs using a first-order accumulation model­(3.97 and 3.73 for PCB 136, and 3.95 and 4.29 for PBDE 154) were in the range of those previously reported in the literature. The suitability of this new nonprotected life stage bioaccumulation protocol for BCF estimation was evaluated by application to widely divergent micropollutants with different accumulation mechanisms. The results were compared with those in the MITE-NITE database for adult rice fish (<i>Oryzias latipes</i>)

Combined comprehensive two-dimensional gas chromatographic analysis of PAH/PASH compounds in complex matrices

A new gas chromatographic method has been developed that is able to quantify polycyclic aromatic hydrocarbons (PAH) and polycyclic aromatic sulfur-containing hydrocarbons (PASH) up to four rings. The method combines the power of both flame ionization detection (FID) and sulfur chemiluminescence detection (SCD) in series on a single comprehensive two-dimensional gas chromatography (GC x GC) system and provides mass fractions of compounds separated by carbon number n (CnHxSy) and class. In addition to PAH and PASH separation, the method is extended toward nonaromatic and monoaromatic (sulfur-containing) compounds (paraffins, naphthenes, monoaromatics, thiols, sulfides, disulfides, and thiophenes). The 95% confidence interval is doubled when a single injection technique is used instead of a more-accurate double injection technique. A flexible correction procedure that combines the advantages of the two-dimensional separation of GC x GC and its ability to easily define overlapping groups between the FID and the SCD chromatograms is applied. The method is validated using theoretical reference mixtures and is applied on three commercial gas oils with sulfur content from 0.16 wt% up to 1.34 wt%. The repeatability is good, with an average of 3.4%, which is in the same range as the much more expensive Fourier transform ion cyclotron resonancemass spectroscopy (FTICR-MS) technique