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As a province that has a very large sea area, North Maluku must be able to become a leading province in the fishery product sector. The mushrooming of fishery product processing businesses carried out by micro-industries in North Maluku is certainly very good but it must also be followed by the nutritional quality of the products produced. One type of nutrition that can be increased in processed fish is calcium, a material that can be used as a source of calcium is also easily available, such as tuna bone meal and anchovies which have a high enough calcium content. In previous research, it was found that the use of tuna fish bone meal had a high effect on the value of canned tuna with an average of 792.9 mg per 180 grams, the fortification of anchovy flour had an effect on product calcium, which averaged 83.34 mg per 180 grams and without preparation with an average calcium value of 21.6 mg per 180 mg. However, it has not been able to reveal the best and proper fortivication to increase the calcium content of the product, so it is necessary to continue with different concentrations for activation.The research started from the preparation stage, manufacturing of fortivication materials, product manufacturing, calcium testing, microbiological testing and statistical analysis, carried out with five treatments, namely without fortivication or 0% (A0), fortivication of tuna fish bone meal 3% (B1), flour. 6% tuna bones (B2), 3% anchovy flour (C1), 6% anchovy flour (C2).From the results of the study it was found that fortivication using tuna bone meal as much as 6% had a high effect on the increase in calcium content in canned tuna with an average of 7.253 ppm. Whereas fortivication using 3% and 6% anchovy flour had an effect on the increase in product calcium with an average value of 473 ppm and 790 ppm, respectively.

The sodium chloride content in the flesh of tuna fish is one of the factors for determining the price in the fishing industry. Titration is a standard method for the analysis of salt and this is time consuming. Near infrared spectroscopy is a potential alternative method for rapid detection without the need for wet chemical assay. Although sodium chloride is infrared inactive, this study investigated the influence of salt on the absorbance of near infrared energy and showed that the sodium chloride content can be determined using changes in the water band at 970 nm. Calibration equations were developed from frozen fish pieces and ground samples using multiple linear regression for the wavelength region of 700–1000 nm. The best result was achieved from frozen samples with a coefficient of determination for the calibration set ([Formula: see text]) = 0.71, standard error of calibration (SEC) = 0.20%, coefficient of determination for the validation set ([Formula: see text]) = 0.64, standard error of prediction (SEP) = 0.26% and bias = − 0.00%. In order to verify the significant variables used to determine infrared inactive sodium chloride, partial least squares regression was performed on frozen samples. The important variable in multiple linear regression and partial least squares regression was the absorbance band at 976 nm attributed to water molecules. The result from partial least squares calibration showed [Formula: see text] = 0.83, SEC = 0.20%, [Formula: see text] = 0.54, SEP = 0.25% and bias = 0.00%. The salt values predicted using the near infrared models were not significantly different from the reference values obtained by the standard titration method at the 95% confidence interval.

The mechanisms of mercury accumulation and distribution in fish tissues are related to its high affinity for sulfhydryl groups in proteins. There is evidence that mercury is distributed unevenly based on the different reactivity of these groups in the various muscle proteins. Tuna fish also shows numerous specialized anatomical features including the structure of the swimming muscles and some form of endothermy, which generates variations in the mercury content between dark and white muscle and between muscle tissues with different lipid content. The aim of the study is to verify, through a suitable sub lot of Thunnus thynnus caught by a static trap in south-western Sardinia, the effective uneven distribution of mercury in the various muscles and also identify the sites representative of the entire carcass. In agreement with other authors, the results show that even in the Bluefin tuna of the Mediterranean, the site “anterior extremity of upper loin (schienale in Italian)” is representative of the mercury average content of muscle tissues as a whole.

This research modified coolbox by mixing sengon wood sawdust and potassium hydroxide-soaked cocofiber. By considering its composition, potassium hydroxide content, and soaking duration, this research was done to find the optimum amount of those three variables to make the best insulator. The best insulator was chosen based on its thermal conductivity, density, and economic value, and the easiness in the making. From the experiment, the chosen composition consists of 30% sengon wood sawdust and 70% potassium hydroxide-soaked cocofiber with content of 15% and soaking duration of 2 hours. With thermal conductivity of 0,352W/mK, density of 0,303gram/cm3, and specimen production cost of Rp607,41, this material was used for composition reference in the making of the coolbox. The experiment of coolbox lasted for 35 hours with 71 temperature data retrievals. The coolbox experiment used 500 gram tuna fish and 2500 gram ice as cooler. The result showed that the lowest temperature for ice inside coolbox was 0,3°C, the lowest temperature of fish was 5°C, and the lowest temperature in coolbox chamber is 17°C. With the ratio of 1:5 for fish and ice, the coolbox insulation using sengon wood sawdust and potassium hydroxide-soaked cocofiber was able to maintain fish temperature below 20°C for 27,5 hours. Meanwhile, the styrofoam coolbox was able to maintain fish with the same condition for 35 hours.

Mercury (Hg) content behaviour was followed along the canning process in muscle samples of tuna fish to point out implications concerning canned tuna consumers. Hg was quantified in the same batch of the Skipjack tuna ( Katsuwonus pelamis ), considering three distinct stages (raw, cooked and canned tuna) independently in both white and dark muscle tissue. Hg concentration data was then used to estimate the weekly tolerable intake of Hg regarding the recommendations from the international agencies. A small but significant difference in Hg concentration between white and dark muscle was observed either in the raw samples (0.115 ± 0.003 μg g −1 against 0.124 ± 0.003 μg g −1 ) as also in the canned samples (0.134 ± 0.003 μg g −1 against 0.155 ± 0.003 μg g −1 ). Overall results indicate an increment in the Hg concentration in both types of muscle throughout the canning process (raw

Fish consumption is one of the major ways through which humans receive exposure to mercury (Hg). The existing forms of Hg in food, particularly Hg bound to proteins, may affect the absorption of Hg by humans and subsequently its potentially toxic effects. However, the knowledge regarding Hg-binding proteins in edible fish muscle is scarce. In the present study, salmon and tuna fish muscles, collected from seven different regions and countries, were analyzed using metallomics- and proteomics-based techniques. The concentration of Hg in sashimi samples ranged from 4.4 to 317.4 ng/g. Size exclusion chromatography (SEC) coupled with inductively coupled plasma mass spectrometer (ICP-MS) showed that beta-actin was a novel Hg-binding protein from the fish muscles, and this protein could also bind bismuth (Bi), silver (Ag), and copper (Cu). Hg bound to beta-actin accounted for approximately 30.2-37.6% of the total Hg in the tuna muscles and was significantly correlated to total Hg in the fish muscles (r = 0.98, p 0.01) and in the fraction of soluble proteins (r = 0.94, p 0.01). These findings suggest that proteins act as the main Hg accumulation sites in edible fish; thus, increasing human exposure to Hg following gastrointestinal digestion.

Several species of tuna fish were analyzed for (210)Po content in their edible muscle tissues. This study was carried out as a part of baseline data generation around a large nuclear power plant situated at Kudankulam, southeast coast of India. The concentration of (210)Po in the muscle tissue ranged from 40.9±5.2 to 92.5±7.9Bq/kg of fresh fish, and the highest activity was recorded for the tuna Euthynnus affinis and the lowest for Auxis thazard. The committed effective dose to the local residents was calculated to be 62.7-141.8μSvyear(-1).

This study aims to determine the performance of hydroxyapatite adsorbents from tuna bone waste against cadmium metal ion removal. Hydroxyapatite adsorbents have been activated physically (calcined at 500°C and 700°C) and chemically (using H3PO4). The adsorbent was then characterized using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). A batch experiment was conducted to study the effect of initial concentration and contact time on cadmium adsorption. The results of SEM and FTIR analysis showed that the best adsorbent was obtained from calcination results at 700°C. The observation shows that the contact time and initial concentration affect the efficiency of adsorption. The highest removal efficiency of cadmium was 86.28% with an adsorption capacity of 44.62 mg/g obtained at the contact time of 150 minutes and an initial concentration of cadmium 100 mg/L. The results of the isotherm study show that the adsorption equilibrium in the cadmium solution follows the Freundlich isotherm model with values R2 = 0.923, N = 9.4339, and KF = 7.92. The adsorption kinetics of cadmium adsorption followed the pseudo-second-order equation with values of K2 and qe at 0.021534 g.mg−1.min−1 and 47.61 mg/g, respectively. The results obtained indicate that hydroxyapatite from tuna bone waste is a promising alternative for cadmium adsorption.

The concentration of total mercury (Hg) and arsenic (As) has been measured in edible and non-edible tissues (flesh, viscera, gill, skin, fin and tail) of two species of tuna fish including 15 yellowfin (Thunnus albacares) and 15 skipjack (Katsuwonus pelamis). They were fished from Chabahar port, the Oman Sea, Iran, in April-May 2011. Atomic absorption spectrometer equipped with cold vapour and hydride generation system was used to determine total concentrations of Hg and As after microwave digestion. Based on the results, the highest and the lowest Hg contents (wet weight basis) in yellowfin and skipjack were observed in viscera (1.29±0.06 and 1.15±0.04 μg/g), and fin and tail (0.48±0.04 and 0.30±0.08 μg/g), respectively. Furthermore, the highest level of As accumulation in yellowfin and skipjack was found in skin (1.99±0.35 and 2.17±0.20 μg/g, respectively), while the lowest was measured in fin and tail (0.19±0.04 and 0.23±0.03 μg/g, respectively). Most yellowfin samples had significantly more heavy meta...

Physical properties (water holding capacity, cohesiveness, chewiness, springiness) and sensory characteristics (cohesiveness, chewiness, springiness and overall) of little tuna fish balls that substituted with arrowroot flour and added with sodium tripolyphosphate (STPP) were investigated. Substituted little tuna fish ball was added with 0%; 0.1%; 0.2%; 0.3% of sodium tripolyphosphate. Results of this study showed that the addition of sodium tripolyphosphate increased water holding capacity, cohesiveness, chewiness, and springiness parameters with respect to better textural properties of substituted little tuna fish balls (p

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) This work describes the evaluation of several parameters for preparing a tuna fish candidate reference material (RM) in order to measure its total Hg and methyl-Hg mass fractions by cold vapor atomic absorption spectrometry (CV-AAS) and solid sampling graphite furnace atomic absorption spectrometry (SS-GF AAS). Best results were acquired after extraction with toluene and L-cysteine for 15 min at 80 degrees C. The parameters investigated were stability of chemical composition during production, homogeneity and analyte segregation. No analyte segregation was observed and the material was shown to be stable even when stored at 50 degrees C for 10 months. Total Hg mass fraction was 3.03 +/- 0.22 mu g g(-1) by CV AAS, 2.99 +/- 0.43 mu g g(-1) by SS-GF AAS and 2.95 +/- 0.15 mu g g(-1) by direct mercury analyser (DMA). Methyl-Hg mass fraction was 2.49 +/- 0.13 mu g g(-1) by CV AAS and 2.44 +/- 0.46 mu g g(-1) by SS-GF AAS. Embrapa Agrossilvipastoril, Ctr Pesquisas Agr, BR-78550970 Sinop, MT, Brazil Univ Sao Paulo, Inst Quim, BR-05508000 Sao Paulo, SP, Brazil Univ Fed Sao Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, Brazil Univ Fed Sao Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, Brazil FAPESP: 2007/56504-6 FAPESP: 2012/11517-1 FAPESP: 2012/11998-0 Web of Science

Reference material plays an important role in analytical measurements. Total arsenic was analyzed in tuna fish samples using three different preparation methods for stability. The stability of total arsenic in tuna fish was evaluated over 12 months, under room temperature storage condition. Each measurement was conducted in triplicate in three different laboratories. Statistical analysis was carried out using Student's t-test. Two different methods were conducted to confirm homogeneity of the candidate reference material in this study. Random bottle number was applied in this analysis. Statistical analysis was carried out and the homogeneity for total arsenic was calculated using the one-way analysis of variance (ANOVA). The statistical results showed no significant changes in stability and the sample was homogeneous. The candidate reference material developed in this study demonstrated its suitability for quality assurance of the total arsenic measurement in tuna fish.

Among different fish slices used for sashimi preparation, tuna is the most popular and preferable fish type for Taiwanese people. To improve the hygienic quality of fish slices, electrolyzed (EO) water containing 10, 50, and 100 mg/L chlorine, was used in combination with CO gas treatment. Effect of different treatment on aerobic plate count (APC), volatile basic nitrogen (VBN), K value, and Hunter L*, a*, b* values of yellow-fin tuna steak during storage (4 °C and −20 °C) were evaluated. It was found that APC, VBN, and K values increased with storage time for all treatment. Except for K value, APC and VBN of tuna steak treated with the combination of more than 50 mg/L chlorine EO water and CO gas had the lowest value after 8 d of refrigerated storage. Hunter a* value of tuna steak treated with only CO gas was the highest, followed by those treated with EO water and CO gas. These results demonstrated that EO water containing 50 mg/L chlorine combined with CO gas treatment in tuna fish steak would be an effective method for enhancing the hygienic quality and freshness for tuna meat and extending refrigerated storage time. Tuna treated with EO water containing 100 mg/L chlorine and CO gas combination had the lowest APC immediately after treatment and reduced further to below detection limit after 1 mo frozen storage at −20 °C.

The present investigation was carried out on the bluefin tuna (Thunnus thynnus) collected during the month of April 2003 from the Straits of Messina. The aim of this study is to determine heavy metal levels (Cd, Cu, Hg, Mn, Pb and Zn) in liver and muscle tissues of 14 Thunnus thynnus of different age and sex and to investigate the relationships between fish sex and size (length and weight) and metal concentrations in the tissues. The concentrations of the various metals were determined by a Varian atomic absorption spectroscopy instrument. The results show significant variations (p0.01) for Hg and Zn concentrations in muscle than in liver samples. Concentrations of Cd and Pb are below the instrumental detection limits in almost all muscle samples. Levels of Hg (3.03 +/- 0.55 microg/g) are above the MRLs only in muscle (1 microg/g) establishing toxicological risks for the consumer. Regression analysis shows a negative correlation between mercury level and weight and length in samples from both female and male. No significant difference between mean heavy metals concentrations and male or female tuna is seen. For greater food safety, it would be advisable to reduce the mercury intake by selecting safer fish, species and size and by the avoidance of tuna fish consumption by pregnant women, young children and old people, who are more sensitive to mercury exposure.

Isotope dilution-inductively coupled plasma mass spectrometry (ID-ICP/MS) was applied to determine mercury in living tissue. Microwave digestion method using HNO 3 /H 2 O 2 media for the dissolution of solid sample was studied. The procedure for accurate determination of total mercury in tuna fish tissue sample by ID-ICP/MS is described. For the method validation, total Hg concentration in tuna fish CRM (BCR CRM 463) was determined by ID-ICP/MS after addition of 202 Hg to CRM followed by acid decomposition of the spiked sample. This method was applied to the determination of Hg in tuna fish CCQM-P39 sample provided by IRMM (Institute for Reference Materials and Measurement, GEEL, Belgium) for the international comparison study.

This study was carried out to determine the current levels of total mercury and methylmercury in the muscle tissue of albacore (Thunnus alalunga) and bluefin tuna (Thunnus thynnus) caught in the Mediterranean sea with the purpose of ascertaining whether the concentrations exceeded the maximum level fixed by the European Commission Decision. Total mercury concentrations ranged from 0.84 to 1.45 mg kg(-1) w.w. (av. 1.17 mg kg(-1) w.w.) and from 0.16 to 2.59 mg kg(-1) (av. 1.18 mg kg(-1) w.w.) in the muscle of albacore and bluefin tuna, respectively. In 78.6% of albacore and in 61.1% of bluefin tuna analysed, total mercury concentrations exceeded the maximum level fixed by the European Commission Decision (Hg = 1 micro g g(-1) wet wt). In the two species, mercury was present almost completely in the methylated form, with percentages between 77 and 100% (av. 91.3%) in albacore and between 75 and 100% (av. 91%) in bluefin-tuna. In order to assess the potential health impact, the estimated weekly intake was calculated. The estimated weekly intake was far above the established Provisional Tolerable Weekly Intake for both species.

Mercury levels in canned tuna fish were determined by cold vapour atomic absorption spectrophotometry while cadmium and lead levels were determined by flame atomic absorption spectrophotometry. The metal contents in the samples, expressed in μg g−1 wet weight, varied from 0.20 to 0.66 with an average value of 0.29 for mercury, from 0.09 to 0.32 with an average value of 0.18 for cadmium and from 0.18 to 0.40 with an average value of 0.28 for lead. The results of this study indicate that tuna fish from the Mediterranean coast of Libya have concentrations well below the permissible levels for these toxic metals. Their contribution to the body burden can therefore be considered negligible.

Tuna fishes were collected in the Straits of Messina (Italy), were dissected and dorsal muscles minced, freeze-dried, ground and sieved. The obtained powder was stabilised by γ-irradiation and filled into brown glass bottles. The homogeneity and stability at +20 °C and +40 °C were verified with regards to the total arsenic, dimethylarsinic acid and arsenobetaine contents. Ten laboratories participated in the certification study. All participants had demonstrated beforehand their ability to produce accurate results for the As speciation in fish tissue. The certified values are: total arsenic (4.8 ± 0.3) mg/kg, arsenobetaine (52 ± 3) μmol/kg, dimethylarsinic acid (2.0 ± 0.3) μmol/kg. The material is available from the BCR since early 1998.

The quality of the aquatic and marine environment can be monitored by the determination of pollutants in organisms living in this environment. Certified reference materials and well-organised proficiency tests are powerful means of ensuring a constant level of quality and verifying the correct application of standardised methods. The preparation of a tuna fish proficiency testing material for the evaluation of quality of As and Hg monitoring in seafood is described. Preparation and characterisation of the material as well as studies on its homogeneity and stability are described. Concentrations of 3.4 ± 0.2 mg/kg total arsenic and 2.91 ± 0.09 mg/kg total mercury have been determined as target values. Moreover indicative values for some trace elements (Cd, Cu, Ni, Pb, Sr) and some major constituents (Al, Br, C, Ca, Cl, Fe, H, K, Mg, N, Na, P, S, Si, Zn) have also been measured.

Determinations of total mercury and methyl mercury (MeHg) are currently performed by a number of laboratories to control the level of contamination of fish samples. The need to improve the quality control of MeHg in fish has justified the organisation of a series of interlaboratory studies in the frame of the BCR-Programme (now renamed Measurements and Testing Programme) of the European Commission, which were successfully concluded by the certification of total mercury and MeHg in two tuna fish materials (CRMs 463 and 464). These materials were collected in the Adriatic Sea, carefully prepared (controlled freeze-drying) and their homogeneity and stability were verified. This paper presents the certification work performed by 14 laboratories from 8 Member States of the European Union. The certified values for total mercury and MeHg are 2.85 ± 0.16 μg/g and 3.04 ± 0.16 μg/g (as MeHg + ) in the CRM 463, and 5.24 ± 0.10 μg/g and 5.50 ± 0.17 μg/g (as MeHg + ) in the CRM 464, respectively.

The applicability of a gold nanoparticle-modified glassy carbon sensor (AuNPs-GCS) for the determination of inorganic mercury in different matrices is demonstrated. Mercury content in some certified samples (Estuarine sediment BCR CRM 277, City waste incineration ash BCR CRM 176, Sea lettuce BCR CRM 279 and Tuna fish ISPRA T22) and in three real samples (drinking water, a plant, a pharmaceutical) has been determined. The analysis was performed by anodic stripping voltammetry using the optimized conditions (deposition potential 0 V, step potential 0.004 V, frequency 150 Hz, amplitude 0.003 V). For each sample the most suitable conditions to take account of matrix effects were identified and adopted.

Cesium-137 is a fission product of 235 U and 239 Pu. After a major nuclear accident, it is released into the atmosphere and in the far field region it will produce radioactively contaminated food and drinking water. This paper will study the specific activity of 137 Cs in three Costa Rican export products: tuna fish, coffee and powdered milk. The average specific activities found are as follows: 0.89±0.41, 1.16±0.76 and 4.53±2.00 Bq kg −1 . They represent low values compared to their derived intervention levels: 1.25 × 10 7 , 1.25 × 10 7 and 2.44 × 10 5 Bq kg −1 , respectively.

An account is given of a systematic, collaborative investigation to detect problems and sources of error in the determination of methylmercury (MeHg) in biological samples. The work was done by a group of analytical laboratories under the auspices of the Community Bureau of References (BCR) of the Commission of the European Communities (EC). The paper presents the organization of three intercomparisons on organic mercury in solution and solid matrices, and the results obtained by the participants. The different analytical steps of the methods used (extraction, clean-up, separation, final detection) are compared and assessed.

Levels of essential and toxic trace elements in six marine species greatly in demand in the international market (canned pink clams, razor clams, clams, king crab, sardines, and frozen albacore tuna fish) were studied. A special laboratory adequately equipped for handling and preparing biological materials, is described. The elements As, Br, Na, Se, Hg, Cr, Fe, Zn and Rb were determined by INAA, while copper and cadmium content were determined using RNAA. Significant differences were found on comparing the contents of some toxic elements in mollusk and other samples of marine food. Various certified reference materials (CRMs) of the IAEA, NIST and NIES were analyzed for quality assurance purposes.

Fifteen brands and types of tuna fish were analyzed for selenium by using differential-pulse cathodic-stripping voltammetry. The cans with high and low concentrations of selenium were analyzed for arsenic by using differential-pulse polarography. Three samples with different levels of added As and a blank were analyzed for each can of tuna fish. Four sample-digestion methods with several variations of each were tested to determine the most reliable technique. An acid-digestion procedure using HNO3 and Mg(NO3)2, 6H2O with an 18-h predigestion step gave the best results, with an average recovery of 98.2%. The selenium concentration of the cans analyzed ranged from 0·034 to 1·20 μg g−1, with an average concentration of 0·68 ± 0·27 μg g−1. The arsenic concentrations of the two cans analyzed were 1·62 μg g−1 and 2·41 μg g−1 in the low- and high-selenium cans, respectively. The selenium concentrations found in the tuna fish are not excessively high and do not seem to pose a problem. The arsenic concentration of 2·41 μg g−1 does, however, approach the maximum allowable level set by the FDA at 2·6 ppm.

The applicability of different chemical modifiers for thermal stabilization and ETAAS determination of mercury is studied. The modifier effect is strongly influenced by the type of acid and acid content in the sample solution. A method is described for mercury determination in tuna fish and sediment after high pressure digestion with nitric acid, using thioacetamide (TAC) as chemical modifier. The method permits determination of 0.5 µg g–1 mercury. A simpler and faster procedure using a slurry technique for the determination of mercury in reference materials (tuna fish, spinach, cabbage and sediments) was also evaluated. Optimal instrumental parameters for mercury determination in slurries are presented. On the basis of the results obtained a new procedure which allows determination of 0.1 µg g–1 mercury was developed.

The toxicity of methylmercury is sufficiently high to justify an evaluation of the risk from the consumption of contaminated food. In the method of risk assessment proposed here, distribution frequencies are assigned to the parameters in question, rather than mean values. Total body burden is estimated by numerical simulation on a digital computer. Based on recorded cases of incipient intoxication and allowing a safety factor of 10, the critical body burden has been estimated at between 5, 4 and 6 mg total mercury. From an application of this approach to the assessment of risk from Mediterranean red tuna fish consumption, it appears that there may exist high frequency consumers whose body burdens, while not in the overtly neurotoxic range, approach the computed critical level.

An economically-feasible technique for the substantial reduction of the total mercury content of slices of tuna fish is described. Extraction at room temperature of the fish slices with 0.5 % cysteine hydrochloride solution is followed by rinsing and washing with sodium bicarbonate solution. The optimal conditions and recycling of the extraction solution are described. The organoleptic properties, protein quality and shelf life of the canned treated fish were satisfactory.

The levels of mercury and selenium in twenty-eight gonad specimens of two species of tunas, i.e., sixteen individuals of yellow fin Thuunus albacares and twelve individuals of albacore Thunnus alalunga, are presented. Total mercury content (T-Hg) correlated significantly between gonad and muscle, and T-Hg in gonad was about 30% of that in the muscle. The ratio of methyl mercury content (MeHg) to T-Hg in gonad was small compared with that in the muscle. Selenium content (Se) was relatively high, and Se in yellow fin was significantly high compared with that in albacore. Moreover, in both the species, Se in the ovary was significantly high com-pared with that in the testis. The molar ratio (Se/Hg) of Se to T-Hg correlated negatively with T-Hg, and tended to get nearer to 1 with the increase in T-Hg.

Trace amounts of transition elements (Co, Cr, Cu, Fe, Mn and V) and other seven elements in optical waveguide samples were determined by INAA. The contents of impurities in ultra-pure materials are less than those of high-purity materials and of G.R. grade. The increase of contamination of trace transition elements and iridium from furnace or crucible are observed in the production of optical glass fibers. Up to seventeen elements were determined in five NBS biological standard reference materials: Oyster Tissue: SRM-1566, Brewers Yeast: SRM-1569, Spinach: SRM-1570, Orchard Leaves: SRM-1571 and Tuna Fish, and in four Japanese biological standard reference materials: Tea Leaves B&C, Pepperbush and Shark Meat. The analytical results in NBS and Japanese standard reference materials are in good agreement with published values and certified values by NBS.

A collaborative study of the determination of mercury in fish has been completed in which wet oxidation of fish tissue in nitric acid, using vanadium as a catalyst, is compared with the AOAC official final action digestion technique, 25.103–25.105, involving a nitric-perchloric acid mixture. The study used tuna fish samples of known mercury content and included spike recovery studies in which methyl mercury solutions of known composition were provided to each laboratory. The study was designed to provide recovery information that bracketed the regulatory level of mercury in fish. The results indicate that the proposed digestion method is at least as precise and accurate as the AOAC method. The proposed method is also more rapid and less hazardous. It has been adopted as official first action.

A method for the determination of methylmercury has been improved by adding several steps to the ordinary process, such as the proteinase digestion of the samples and continuous extraction of the digest with benzene, and by utilizing p-nitrobenzyl chloride as an internal standard in gas chromatographic analysis. The method thus modified eliminated the emulsion formation, one of the most serious troubles in ordinary method, throughout the whole procedure. The new method revealed 93% of average recovery and less than 1.7% of deviation. The improved procedure was used to estimate the ratio of methylated mercury to total mercury in tuna fish and the results are presented.

Determination of total arsenic was strongly influenced by the properties of the spesies. In a sample of tuna fish, the total arsenic concentration (90-95%) mostly comes from organic arsenic species, arsenobetain (AB). AB in particular, was not decomposed to arsenate which can lead to a serious error in quantification when a hydride generator step is additionally used in the analysis scheme. This research was done to compare three different types of sample preparations, namely dry ashing, water extraction, and microwave digestion, for measuring the total arsenic using HG-QF-AAS, GF-AAS and ICP-MS measurements. HG-QF-AAS and ICP-MS gave similar concentrations of total arsenic in a tuna fish sample, which were 3.49±0.08 μg g-1 and 3.56±0.014 μg g-1, respectively. Meanwhile, the result from GF-AAS measurements was about a half of the others. The results of this research can be used as a reference for determination of total arsenic in tuna fish samples.

Methylmercury-forming activity in vitro and total vitamin B12 content in yellowfin tuna livers were determined. A good correlation (R=0.9) was found between the total vitamin B12 content and the mercury-methylating activity in vitro ; the latter was previously shown to correlate well with the amount of methylmercury accumulated in the livers, and the results thus suggest that vitamin B12 may play a role in the methylmercury accumulation in tuna fish.

Determinations of the potassium levels of light and dark muscle tissues were made for tuns fish samples from the Central Pacific. The mean potassium content was determined to be 2.3 mg/g for these tissues and was used as an index to calculate the radioactivity to be expected from K/sup 40/ at 4.2 dis/min per gram of wet tissue. The levels of potassium in light and dark muscle samples were not significantly different. (auth)

The objective of the present investigation was to estimate the arsenic concentration in the edible muscle of Thunnus thynnus and Thunnus toggel (hereafter called tuna and longtail tune) as they have great commercial value. These fish are widely available along the coastal line of Pakistan and are consumed abundantly in large bulk. Thus, it was felt justifiable on the basis of safety of human health that data, in the first instance, be obtained on arsenic concentration in tuna as a function of weight to check whether the metal distribution was species-specific or it depended on individual mode of development. The data, the first of the kind so far presented on the Arabian Sea tuna, would thus provide the required baseline quantitative information needed in future studies on the physiological processes regulating the distribution and uptake of arsenic by these and other species of fish common to the region.

Mercury accumulated in tuna fish is mostly in the form of methylmercury (KAMPS et al. 1972, RIVERS et al. 1972, PAN-HOU & IMURA 1980). It is most probable that the accumulation of methylmercury is via the food chain. Yet, the possibility of mercury methylation in tuna fish cannot be ruled out, since we have reported that liver homogenates from some kinds of tuna fish, which contained higher level of methylmercury, have a relatively high ability to form methylmercury from inorganic mercury in vitro (IMURA et al. 1972).

Toxicological evaluation of hazard is required on any new chemical entity to which man may be exposed, or any novel form of exposure to an already known substance. Exposure to this chemical entity may be as: (i) A medicinal substance administered therapeutically to man by any route, e.g. orally, per rectum, topically, intravenously, intramuscularly, subcutaneously or by inhalation. (ii) A veterinary medicinal substance present as a residue in meat, eggs or milk, e.g. steroidal hormone, oestrogen, veterinary therapeutic substance or growth promoter. (iii) An agricultural residue in vegetable material, pesticide or selective herbicide. (iv) A food colour or preservative. (v) An environmental pollutant in air or water or even in food e.g. mercury in tuna fish or cadmium in shell fish. (vi) As an industrial exposure, e.g. vinyl chloride.

Selenium balance was determined in six young men fed for 45 days a formula depletion diet (33 to 36 micrograms Se/day) then fed for 25 days a repletion of diet (depletion diet plus 200 micrograms Se/day as high-Se wheat or wheat plus tuna fish). After 12 days of adaptation, Se balance during depletion was rather constant at -21 micrograms/day and Se losses in urine and feces were 54 micrograms/day. During repletion, Se balance was +64 micrograms/day for the first 12 days and +25 micrograms/day thereafter and the subjects regained all the Se lost during depletion. If the gastrointestinal absorption of the food Se in North Americans and New Zealanders is similar (80%), young North American men need a dietary Se intake of about 70 micrograms/day to replace losses and maintain body stores.

Approximately three-quarters of the total mercury content originally present in tuna fish could be removed by two-hour extraction of one part of shredded precooked fish with 7.5 parts of dilute hydrochloric acid containing 0.33% cysteine hydrochloride. Nearly two-thirds of the mercury could be removed from 1.5 cm thick slices of precooked fish by 24-hour extraction under the same conditions, at about 2 °C.

THE discovery of environmental mercury contamination in this country has led to increasing concern about mercury toxicity. Mercury poisoning is not a new phenomenon — knowledge of its manifestations goes back at least 1500 years. But the tragedies of Minamata and Niigata in Japan, and the less widely known but no less tragic epidemics in Iraq, Pakistan and Guatemala in the past decade, represent a distinctly different clinical entity: alkyl mercury poisoning. A key concept developed by the extensive Japanese and Swedish investigations in this field is that alkyl mercury compounds (chiefly methyl, the form in which mercury exists in . . .

Excerpt In the wake of the mercury scares of 1970-1971 that were triggered by the revelation of pervasive contamination of our food supply, particularly tuna fish, an intensive search began for all...