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Due to the analytical challenges of detecting and quantifying nanoparticles in seawater, the data on distributions of NPs in the marine environment is limited to qualitative studies or by ensemble measurements subject to various analytical artifacts. Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) allows determination of individual inorganic NPs at environmentally relevant concentrations, yet only few studies have been conducted on selected elements in surface sea water. Here, a sequential multi-element screening method was developed and implemented to provide a first survey of the horizontal and vertical distributions of inorganic nanoparticles and trace elements in a pristine Norwegian fjord prospect for submarine tailings deposition. Statistical control of false-positive detections while minimizing the size detection limit was ensured using a novel raw signal processing. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) gave confirmative and qualitative information regarding particle morphology and composition. Following SP-ICP-MS screening for particles of 16 elements, particulate Al, Fe, Mn, Pb, Si and Ti were found and determined to mass concentrations in ng/L of 1–399, 1–412, below limit of detection (8 particles per liter. Total metals concentrations were at least an order of magnitude higher, at concentrations in μg/L of 1–12 for Al, 2–13 for Fe, 0.3–11 Mn, 0.02–0.5 for Pb, 46 to 318 Si and 0.04–0.4 for Ti. A strong depth dependence was observed for both trace elements and particles with concentrations increasing with depth. Our results provide a baseline for the fjord and new data on environmental levels of both total metals and metal containing nanoparticles including the vertical and horizontal distribution of natural nanoparticles.

Background Diet is a major source of human exposure to hazardous environmental chemicals, including many perfluoroalkyl acids (PFAAs). Several assessment methods of dietary exposure to PFAAs have been used previously, but there is a lack of comparisons between methods. Aim To assess human exposure to PFAAs through diet by different methods and compare the results. Methods We studied the dietary exposure to PFAAs in 61 Norwegian adults (74% women, average age: 42 years) using three methods: i) by measuring daily PFAA intakes through a 1-day duplicate diet study (separately in solid and liquid foods), ii) by estimating intake after combining food contamination with food consumption data, as assessed by 2-day weighted food diaries and iii) by a Food Frequency Questionnaire (FFQ). We used existing food contamination data mainly from samples purchased in Norway and if not available, data from food purchased in other European countries were used. Duplicate diet samples (n=122) were analysed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) to quantify 15 PFAAs (11 perfluoroalkyl carboxylates and 4 perfluoroalkyl sulfonates). Differences and correlations between measured and estimated intakes were assessed. Results The most abundant PFAAs in the duplicate diet samples were PFOA, PFOS and PFHxS and the median total intakes were 5.6 ng/day, 11 ng/day and 0.78 ng/day, respectively. PFOS and PFOA concentrations were higher in solid than liquid samples. PFOS was the main contributor to the contamination in the solid samples (median concentration 14 pg/g food), while it was PFOA in the liquid samples (median concentrations: 0.72 pg/g food). High intakes of fats, oils, and eggs were statistically significantly related to high intakes of PFOS and PFOA from solid foods. High intake of milk and consumption of alcoholic beverages, as well as food in paper container were related to high PFOA intakes from liquid foods. PFOA intakes derived from food diary and FFQ were significantly higher than those derived from duplicate diet, but intakes of PFOS derived from food diary and FFQ were significantly lower than those derived from duplicate diet. We found a positive and statistically significant correlation between the PFOS intakes derived from duplicate diet with those using the food diary (rho=0.26, p-value=0.041), but not with the FFQ. Additionally, PFOA intakes derived by duplicate diet were significantly correlated with estimated intakes from liquid food derived from the food diary (rho=0.34, p=0.008) and estimated intakes from the FFQ (rho=0.25, p-value=0.055). Conclusions We provide evidence that a food diary or a FFQ-based method can provide comparable intake estimates to PFOS and PFOA intakes derived from a duplicate diet study. These less burdensome methods are valuable and reliable tools to assess dietary exposure to PFASs in human studies.

Meat samples of 84 minke whales (Balaenoptera acutorostrata) mainly from the Barents Sea, collected between 1 May and 16 August 2011, were analyzed for total mercury, methylmercury, cadmium, lead, total arsenic, inorganic arsenic and selenium. The average total mercury concentration found was 0.15 ± 0.09 mg/kg, with a range from 0.05 to 0.49 mg/kg. The molar ratio of selenium to mercury varied between 1.0 and 10.3. Cadmium content ranged from 0.002 to 0.036 mg/kg, while the content of lead in whale meat ranged from

Despite the ban of nitrofurans (NFs) for use in food production in many countries in the 1990s, NF metabolites in food are still regularly detected during import control testing. We have developed a confirmatory routine method for the detection and quantification of NF metabolites in seafood using LC-MS/MS and validated the method according to the strict criteria in European legislation and Codex Alimentarius. Method characteristics were found to fulfill the criteria. We report for the first time a new false positive for 1-amino-2,4-imidazolidinedione (AHD), the metabolite of Nitrofurantoin (NFT). By using optimized washing procedures, the non tissue bound false positives can be minimized. The results from the validation on both lean and fatty fish and crustaceans, results from proficiency tests and routine use over many years, demonstrates that the method is fit for purpose to determine NF metabolites in the seafood category. acceptedVersion

Hg pollution released from the U-864 submarine sunk during WWII and potential introduction of that Hg into the marine food chain have been studied by a combination of quantitative Hg and MeHg determination and Hg isotopic analysis via cold vapor generation multicollector inductively coupled plasma-mass spectrometry (CVG-MC-ICP-MS) in sediment and Cancer pagurus samples. The sediment pollution could be unequivocally linked with the metallic Hg present in the wreck. Crabs were collected at the wreck location and 4 nmi north and south, and their brown and claw meat were analyzed separately. For brown meat, the δ202Hg values of the individuals from the wreck location were shifted toward the isotopic signature of the sediment and, thus, the submarine Hg. Such differences were not found for claw meat. The isotope ratio results suggest direct ingestion of metallic Hg by C. pagurus but do not offer any proof for any other introduction of the submarine Hg into the marine food chain.

Organotin compounds are anthropogenic metal species with multiple uses as pesticides, preservatives, antifouling agents, biocides, and catalysts. Butyltins are the main organotin compounds found in biota, and the highest levels are found in marine foodstuffs. In this paper, we present the figures of merit for an in-house validated method for routine analysis of butyltins in seafood using GC inductively coupled plasma isotope dilution MS. The working range of the method spanned several orders of magnitude from 3.3–1013, 2.4–785, and 0.3–900 ng Sn/g dry weight for monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT), respectively. The trueness of the method was evaluated by analyzing Certified Reference Materials (CRMs) ERM CRM 477 (Mussel Tissue) and NIES CRM 15 (Scallop). Recoveries, with RSD % in parentheses, were 78 (±14), 80 (±6), and 88% (±8%) for MBT, DBT, and TBT in ERM CRM 477 and 96% (±5%) for TBT in NIES CRM 15. Good agreements were found between experimental uncertainties and uncertainties predicted for single-laboratory validated methods calculated from the maximum standard measurement uncertainty function. The method has proven to be robust, and the wide range of seafood validated ensures that the method is applicable for measuring butyltins in marine tissue.

The aim of this paper is to evaluate the food safety of the red king crab from Norwegian waters and obtain information on possible geographical and gender differences. Samples of claw and leg meat of 185 red king crabs (Paralithodes camtschaticus), collected from 23 positions in the Barents Sea, were analysed for dioxins, furans, non-ortho and mono-ortho PCBs, non dioxin-like PCBs, polybrominated diphenyl ethers, and perfluorinated alkyl substances and elements, such as arsenic, cadmium, mercury and lead. The concentrations of persistent organic pollutants and metals were low compared to maximum levels laid down in European regulations. Hence, red king crab is a safe food. Significant differences in the concentrations of metals among different areas, and between male and female crabs, were found. Positive correlations were found between carapace length and mercury, methylmercury and cadmium concentrations, and between fat and arsenic and inorganic arsenic concentrations.

Residue levels of the antibacterials enrofloxacin and ciprofloxacin were analysed in 15 commercially relevant animal by-products (ABPs). Enrofloxacin was detected in all ABPs, and ciprofloxacin was detected in 11 of 15 ABP samples. Feed to muscle and skin carry –over of low background enro- and ciprofloxacin levels were assessed by applying a simple toxicokinetic model. The muscle and skin uptake and elimination rates were established in Atlantic salmon (Salmo salar L.) fed enrofloxacin enriched diets (100 µg kg-1 ‘low’ and 4000 µg kg-1 ‘high’) in triplicate for 41 days followed by a 90 days depuration period. The terminal half-lives were 17 ± 0.4 and 18 ± 0.7 days, and uptake rates were 9.3 ± 3.3 and 11 ± 3.1 (day-1) for the ‘low’ and ‘high’ groups, respectively. Only fish fed high background levels had quantifiable levels of the metabolite ciprofloxacin with a formation of 0.25 ± 0.01% day-1. The toxicokinetic carry-over model predicted muscle and skin steady state levels of 1.8 µg kg-1 when fed theoretically high enrofloxacin levels (158 µg kg-1), which is below the EU limit of 100 µg kg-1 for enrofloxacin in finfish food products. The antibacterial residue levels could however be detected in EU food surveillance programmes.

Arsenolipids are the major arsenic species present in marine oils. Several structures of arsenolipids have been elucidated the last 5 years, demonstrating the chemical complexity of this trace element in the marine environment. Several commercial fish oils and marine oils, ranging in total arsenic concentrations from 1.6 to 12.5 mg kg(-1) oil, were analyzed for arsenolipids using reversed-phase high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The arsenolipids were quantified using three different arsenic-containing calibration standards; dimethylarsinate (DMA), triphenylarsinoxide (Ph₃AsO) and a synthesized arsenic-containing hydrocarbon (AsHC) (dimethylarsinoyl nonadecane; C₂₁H₄₃AsO). The observed variation in signal intensity for arsenic during the gradient elution profile in reversed-phase HPLC was compensated for by determining the time-resolved response factors for the arsenolipids. Isotopes of germanium ((74)Ge) and indium ((115)In) were suited as internal standards for arsenic, and were used for verification of the arsenic signal response factors during the gradient elution. Dimethylarsinate was the most suitable calibration standard for the quantification of arsenolipids, with recoveries between 91% and 104% compared to total arsenic measurements in the same extracts. A range of marine oils was investigated, including oils of several fish species, cod liver and seal, as well as three commercial fish oils. The AsHCs - C₁₇H₃₈AsO, C₁₉H₄₂AsO and C₂₃H₃₈AsO - were identified as the major arsenolipids in the extracts of all oils by HPLC coupled with quadrupole time-of-flight mass spectrometry (qTOF-MS). Minor amounts of two arsenic-containing fatty acids (AsFAs) (C₂₃H₃₈AsO₃ and C₂₄H₃₈AsO₃) were also detected in the oils. The sum of the AsHCs and the AsFAs determined in the present study accounted for 17-42% of the total arsenic in the oils.

The reactivity of 1,1-diethoxy-3-(1,3-dithian-2-yl)propan-2-one, a diacetal of oxobutanedial, and some of its derivatives toward selected reagents has been studied. As expected, hydride and Grignard-type additions take place at the oxo moiety only and give the corresponding alcohols in good-to-excellent yields. Standard reductive amination occurs at the oxo moiety as well, but the reaction was in most cases not selective and furnished the expected amine mixed with 3-(1,3-dithian-2-yl)-1,1-diethoxypropan-2-ol. The conversion of the diethyl acetal moiety to an aldehyde group is generally an efficient transformation, but some aldehydes are unstable, making the deprotection useless. If the acetal contains a tertiary alcohol or a benzyloxy moiety, however, stable products are formed in good yields. Attempts to convert the 1,3-dithiane substituent into an aldehyde group without concomitant decomposition of the product were totally unsuccessful. The chemical potential of this moiety, therefore, has to be utilized at an earlier stage and under different conditions.

The level of perfluorinated alkyl substances (PFAS) was determined in North East Arctic cod (Gadus morhua) liver samples from 15 Norwegian fjords and harbors. Five harbors in the eastern part of Norway, six harbors in the western part and four harbours in the northern part. A total of 200 samples were analyzed for 16 PFAS. Determination of PFAS were carried out by LC-MS/MS following sample clean up by solid phase extraction and ultracentrifugation. The predominating PFAS was PFOS, which was found to be higher than the level of quantification (1.5 μg kg-1 wet weight) in 72% of the samples. The highest level of PFOS found was 21.8 μg kg-1 wet weight in a sample from Kragerø in the eastern part of Norway. A significantly higher level of PFOS was found in the eastern fjords and harbors compared to fjords and harbors in the western and northern part of Norway. Within the northern fjords and harbors elevated PFOS levels were found in Narvik, which may indicate a local source there. Variations in PFOS of the cod livers thus reflect differences in levels of pollution between the areas.

Feed additives are typically used in intensive farming production over long periods, and hence, they can accumulate in farmed animal tissues. Concerns regarding the use of ethoxyquin as an antioxidant feed additive, have recently arisen due to its potential conversion into a series of transformation products (TPs). The aim of this work was to characterize the TPs of ethoxyquin in fish feed by a novel approach based on the use of traveling-wave ion mobility spectrometry (TWIMS) coupled to high-resolution quadrupole time-of-flight mass spectrometry (QTOFMS). First, ethoxyquin was oxidized under controlled conditions and the generated TPs were added to a comprehensive database. Atlantic salmon feeds were then screened for ethoxyquin TPs using both targeted and untargeted approaches. Twenty-seven TPs were tentatively identified during the oxidation experiments, fifteen of them also being present in the feed samples. In addition, ten other potential TPs were detected in fish feed following the untargeted approach. Thirty-one of these TPs have been reported for the first time in this work through the oxidation experiments and the feed samples. Therefore, this study provides valuable information on the oxidative fate of ethoxyquin in feed, which can be used for future evaluations of potential risk related to this additive.

The contents of total arsenic and inorganic arsenic were determined in fillet samples of Northeast Artic cod, herring, mackerel, Greenland halibut, tusk, saithe and Atlantic halibut. In total, 923 individual fish samples were analysed. The fish were mostly caught in the open sea off the coast of Norway, from 40 positions. The determination of total arsenic was carried out by inductively coupled plasma mass spectrometry following microwave-assisted wet digestion. The determination of inorganic arsenic was carried out by high-performance liquid chromatography-ICP-MS following microwave-assisted dissolution of the samples. The concentrations found for total arsenic varied greatly between fish species, and ranged from 0.3 to 110 mg kg(-1) wet weight. For inorganic arsenic, the concentrations found were very low (0.006 mg kg(-1)) in all cases. The obtained results question the assumptions made by the European Food Safety Authority (EFSA) on the inorganic arsenic level in fish used in the recent EFSA opinion on arsenic in food.

Selected 5-substituted derivatives 4 of 1,1-diethoxy-5-hydroxypent-3-yn-2-one were treated with propane-1,3-dithiol under various conditions. The unprotected hydroxy ketones underwent cyclization during the dithiol addition and gave the corresponding 3-(diethoxymethyl)-2-oxa-6,10-dithiaspiro[4.5]decan-3-ols 5 in 80–90% yield as the only products (Scheme 3 and Table 1). These products can be regarded as partly modified carbohydrates in the furanose form. When the benzyl-protected analogues 10-Bn of the 1,1-diethoxy-5-hydroxypent-3-yn-2-one derivatives were treated with the same dithiol, however, no cyclization occurred; instead the corresponding 3-{2-[(benzyloxy)methyl]-1,3-dithian-2-yl}-1,1-diethoxypropan-2-one derivatives 11-Bn were formed in good yield (up to 99%; Table 4). These 1,3-dithianes were and are in the process of being converted to a number of new carbohydrate analogues, and here are reported high-yield syntheses of functionalized molecules 17 belonging to the 5,5-diethoxy-1,4-dihydroxypentan-2-one family of compounds (Table 7), via 15-Bn (Table 5) and 16-Bn (Table 6 and Scheme 8).

Currently, there is no legal limit for methyl mercury (MeHg) in food; thus, no standardized method for the determination of MeHg in seafood exists within the European jurisdiction. In anticipation of a future legislative limit an inductively coupled plasma isotope dilution mass spectrometry (GC-ICP-ID-MS) method was developed in collaboration with the European Standardization Organization (CEN). The method comprises spiking the tissue sample with Me201Hg, followed by decomposition with tetramethylammonium hydroxide, pH adjustment and derivatization with sodium tetraethylborate, and finally organic extraction of the derivatized MeHg in a hexane phase. Subsequently, the sample is analyzed via GC-ICP-MS and the result calculated using the ID equation. The working range of the method was 0.0005–1.321 mg/kg MeHg in marine tissue, with an internal reproducibility (RSD) of 12–1%. The method was validated based on statistical measures, such as the z-scores, using the commercially available reference materials from National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1566b, NIST SRM 2977 and National Research Council of Canada (NRCC) TORT 2, NRCC, DORM 3, NRCC DOLT 4, and European Reference Material (ERM) CE 464. Z-scores for all standard reference materials, except for NIST SRM 1566b, were better than |1.5|. The wide range of marine tissues used during the validation ensures that the method will be applicable for measuring of MeHg in seafood matrixes of all kinds.

In January 2006 it was reported from Russia that Greenland halibut (Reinhardtius hippoglossoides) caught in the Barents Sea had shown mercury levels exceeding the European Union's upper limit of 0.5 mg/kg wet weight (ww) for this species. These findings were confirmed in a small study from the same area. To gain more knowledge, a larger study was initiated to investigate the levels of mercury in Greenland halibut caught off the coast of northern Norway. A total of 320 Greenland halibut were caught in this area in May 2006. Individual fish were filleted and analysed for mercury, arsenic, cadmium and lead. Round weight of the fish varied between 1.1 and 8.1 kg. Fish age varied between 12 and 29 years. The highest mercury concentration measured in muscle tissue was 1.1 mg/kg ww. The highest concentrations were found in female fish. Mercury concentration was positively correlated with fish size and negatively correlated with fat content. Fish captured in the easternmost part of the investigated area ...

A two-compartmental model for the kinetics of carry-over of the brominated flame retardant α-hexabromocyclododecane (HBCD) from feed to the fillet of farmed harvest-sized Atlantic salmon (Salmo salar L.) was developed. The model is based on a fat compartment for storage of the lipophilic α-HBCD and a central compartment comprising all other tissues. Specific for this model is that the salmon has a continuous growth and that fillet contaminant levels are explained by both the fat and the central compartments. The uptake and elimination kinetics are obtained from experimental data where consumer sized (start weight approximately 1 kg) Atlantic salmon was fed α-HBCD spiked feed (280 ± 11 µg kg−1) for 2 months followed by a depuration period of 3 months. The model was used to simulate the HBCD feed-to-fillet transfer in Atlantic salmon under realistic farming conditions such as the seasonal fluctuations in feed intake, growth and fillet fat deposition. The model predictions gave fillet concentrations of 0.2–1.8 µg kg−1 depending on the level of fish oil inclusion in the salmon diets when using fish oil with high POP background levels. Model simulations show that currently farmed Atlantic salmon can contribute to a maximum of 6% of the estimated provisional food reference dose for HBCD.

A number of 1-substituted and 1,1-disubstituted (E)-4,5,5-triethoxypent-3-en-1-ols (1) have been converted to perfluoroalkylated tetrahydrofurans and tetrahydropyrans in a selective fashion by 1-iodoperfluoroalkane addition under radical conditions using sodium dithionite (Na2S2O4) as radical initiator. Direct perfluoroalkylation of 1 gave the former products only, and the yields were moderate (50–75 %), but when 1 was converted to corresponding 6-substituted and 6,6-disubstituted 2,3-diethoxy-5,6-dihydro-2H-pyrans before perfluoroalkylation was carried out, the transformation turned out to be significantly more successful and afforded, as the only product, 6-substituted and 6,6-disubstituted 2-ethoxy-4-(perfluoroalkyl)tetrahydropyran-3-ones in 77–100 % yield as stereoisomeric mixtures. Subsequent reduction of the keto group with sodium borohydride in ethanol was uneventful and completed the syntheses of a range of 4-perfluorobutylated tetrahydropyran derivatives; the yields in this step were in the 81–94 % range. The best result was obtained with (E)-2-methyl-5,6,6-triethoxyhex-4-en-2-ol which was converted to a diastereoisomeric mixture of 2-ethoxy-6,6-dimethyl-4-(perfluorobutyl)tetrahydropyran-3-ol in 85 % yield in three steps. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

With 3,3,4,4-tetraethoxy-1-butyne as starting material, we are investigating the preparation of a range of alkylated, partially deoxygenated carbohydrate derivatives. In the lecture, an overview of recent results was given, with particular emphasis on progress in the synthesis of perfluoroalkyl-substituted deoxygenated analogs. Since many of the results discussed in the lecture have recently been or are in the process of being published, this paper focuses on our recent advances in preparing fluorinated analogs.

Organic synthesis has been applied to detect potential Tonalide (AHTN) transformation products in a semi-quantitative way in environmental samples by using a well-established trace-analytical method, developed for the quantification of the parent compound AHTN. For the first time, indications for the presence of transformation products of the synthetic musk compound 1-(5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphthalenyl)ethanone (1) (Tonalide®, AHTN) have been found in the environment. Pure standards of the detected products were obtained by multistep syntheses from Tonalide®. Two main derivatives, 3-acetyl-5,6,7,8-tetrahydro-5,5,7,8,8-pentamethyl-2-naphthalenecarbaldehyde (2) and (3-ethyl-5,6,7,8-tetrahydro-5,5,7,8,8-pentamethyl-2-naphthalenyl)methanol (4), and three minor products, (5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphtalenyl)methanol (6), 5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphtalenecarbaldehyde (7), and methyl 5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphthalenecarboxylate...

3,3,4,4-Tetraethoxy-1-butyne, available in high yield in four simple steps from ethyl vinyl ether, is a highly functionalized alkyne, which appears to be a versatile starting material for the synthesis of a range of alkylated, more-or-less deoxygenated carbohydrate mimics. However, many of the reactions used to achieve extension and subsequent structural modification of the carbon chain as well as removal of the protecting groups turn out to be rather sensitive to the substituents’ steric and electronic influence. As a result, the reactivity pattern that emerges is somewhat complex.

Eight laboratories participated in an inter-laboratory method-performance (collaborative) study of a method for the determination of mono methylmercury (MMHg) in foodstuffs of marine origin by gas chromatography inductively coupled plasma isotope dilution mass spectrometry (GC–ICP-IDMS) after dissolution, derivatisation and extraction of the species. The method was tested on seven seafood products covering both a wide concentration range and variations in the MMHg concentrations as well as matrix compositions. The samples were mussel tissue, squid muscle, crab claw meat, whale meat, cod muscle, Greenland halibut muscle and dogfish liver (NRCC DOLT-4), with MMHg concentrations ranging from 0.035 to 3.58mg/kg (as Hg) dry weight. Repeatability relative standard deviations (RSDr) for MMHg ranged from 2.1% to 8.7%. Reproducibility relative standard deviations (RSDR) ranged from 5.8% to 42%. All samples showed HorRat value below 1.0, except for the sample with the lowest MMHg content, mussel tissue, with a HorRat value of 1.6.

MeONa-mediated addition of dithiol (II) to alkynes (I) is accompanied by an intramolecular cyclization to afford spiro compounds (III), which can be regarded as partly modified furanose derivatives.

This study is one of several baseline studies that will provide basic and reliable information about the content of undesirable substances in important species of fish caught in Norwegian waters. Concentrations of metals in the muscle and liver of more than 800 Northeast Arctic cod caught at 32 sites in the Barents Sea are reported. The highest concentration of both mercury in the muscle and cadmium in the liver was found in cod caught in the western part of the Barents Sea, while the highest concentration of total arsenic was found in cod from the eastern part. The arsenic concentrations varied greatly among individual fish, ranging from 0.3 to 170 mg kg−1 wet weight in the muscle. Such high levels of total arsenic have never previously been reported in any fish, and the primary factor for these high concentrations is likely to be the shrimp in the cod diet.

The aim of this study was to examine Peruvian anchovy oil fatty acid (FA) compositions, and to test the possibility of using the FA data to classify the oils according to geographical origin along the Peruvian coast. The levels of contaminants in a representative set of samples were determined to examine the general levels and investigate if such measurements could aid in future discrimination between oils. The FA results showed that the two known stocks of Peruvian anchovy displayed different levels of docosahexaenoic acid (DHA, 22:6n-3) (southern stock; 14.4 ± 0.8% versus central-northern stock; 9.9 ± 1.2%). However, principal component analysis (PCA) of the FA data indicated clusters according to three regions; North, Center and South. Using a data set of 57 anchovy samples and 21 FA as input, a probabilistic neural network (PNN) was constructed. For the validation data sets, “North” oils was predicted accurately 100% of the time, “Center” oils 100% and “South” oils 83% of the time. The levels of contaminants in the oils determined were low in all but one sample.

The molecular mechanisms underlying the neurotoxicity of methylmercury (MeHg), a ubiquitous environmental contaminant, are not yet fully understood. Furthermore, there is a lack of biomarkers of MeHg neurotoxicity for use in environmental monitoring. We have undertaken a proteomic analysis of brains from Atlantic cod (Gadus morhua) exposed to 0, 0.5 and 2 mg/kg MeHg administered by intraperitoneal injection. The doses were given in two injections, half of the dose on the first day and the second half after 1 week, and the total exposure period lasted 2 weeks. Using 2-DE coupled with MALDI-TOF MS and MS/MS, we observed the level of 71 protein spots to be 20% or more significantly altered following MeHg exposure, and successfully identified 40 of these protein spots. Many of these proteins are associated with main known molecular targets and mechanisms of MeHg-induced neurotoxicity in mammals, such as mitochondrial dysfunction, oxidative stress, altered calcium homeostasis and tubulin/disruption of microtubules. More interestingly, several of the affected proteins, with well-established or recently demonstrated critical functions in nervous system-specific processes, have not previously been associated with MeHg exposure in any species. These proteins include the strongest up-regulated protein, pyridoxal kinase (essential for synthesis of several neurotransmitters), G protein (coupled to neurotransmitter receptors), nicotinamide phosphoribosyl-transferase (protection against axonal degeneration), dihydropyrimidinase-like 5 (or collapsin response mediator protein 5, CRMP-5) (axon guidance and regeneration), septin (dendrite development), phosphatidylethanolamine binding protein (precursor for hippocampal cholinergic neurostimulating peptide) and protein phosphatase 1 (control of brain recovery by synaptic plasticity). The results of the present study aid our understanding of molecular mechanisms underlying MeHg neurotoxicity and defense responses, and provide a large panel of protein biomarker candidates for aquatic environmental monitoring.

The title compound is a stable chemical entity, easily prepared on a large scale using cheap chemicals. The compound is densely functionalized, and by taking advantage of the chemical properties of the various functional groups, a variety of compounds have been synthesized. Some syntheses involve deprotection of the ketal moiety to form the corresponding α,β-unsaturated acetylenic ketones, which appear to react with nucleophiles in a Michael fashion. This has enabled us to develop a new furan synthesis.