Search

A statistical study of recovery has been carried out in five mineralization procedures: i) HNO3/H2SO4 (1:1), 45°C/15 h; ii) HNO3, 100°C (teflon pump)/l h.; iii) HNO3/H2SO4 (1:1), 100°C (teflon pump)/l h; iv) H2SO4/HCI (1:1), 100°C (teflon pump)/l h; and v) Lumaton, 45°C/24 h, for determination of mercury (cold vapor - A.A.S.) in muscle of fish. Only in method 1 there is no evidence of the systematic error (P > 0.05). This method was applied to 449 samples of fresh and salted fish. Mean concentrations of mercury ranged of 0.014 ppm ( Pagellus erythrinus ) to 0.970 ppm ( Lepidopus caudatus ) for fresh fish, and for salted fish between 0.043 ppm ( Diplodus sargus cadenati ) and 0.172 ppm ( Galeorhinus galeus ). One can conclude that the low mercury level of analyzed samples was lower than fish species from some polluted areas of the Mediterranean Sea. No significant differences were observed between the mean concentrations of fresh and salted fish.

A total of 20 metals (Na, K, Ca, Mg, B, Ba, Co, Cr, Cu, Sr, Fe, Li, Mn, Mo, Ni, V, Zn, Al, Cd, and Pb) were analyzed by inductively coupled plasma optical emission spectrometry in muscle and liver tissue from a total of 28 examples of the fishes Mullus surmuletus and Pseudupeneus prayensis marketed in Tenerife, Canary Islands (Spain). Significant differences (P < 0.05) in B, K, Mg, Mn, and Na concentrations were found between muscle and liver. The mean concentrations of K (1,388.04 mg/kg wet weight [wet wt]) and Mg (153.33 mg/kg wet wt) were higher in muscle than in liver (697.49 and 114.21 mg/kg wet wt, respectively). The mean concentrations of B in liver (0.18 mg/kg wet wt), Mn (0.70 mg/kg wet wt), and Na (892.09 mg/kg wet wt) were higher than those in muscle (0.15, 0.11, and 375.55 mg/kg wet wt, respectively). The mean concentrations of Al, Cd, and Pb in muscle tissue were 2.72 mg/kg wet wt and 4.28 and 10.29 μg/kg wet wt, and those in liver tissue were 31.31 mg/kg wet wt and 612.91 and 232.08 μg/kg wet wt, respectively. When comparing the two fish species, the muscle tissue of M. surmuletus has significantly higher concentrations (P < 0.05) of Al, B, Ba, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Sr, and Zn than did P. prayensis muscle, whereas the concentrations of Cd and V were significantly higher (P < 0.05) in P. prayensis muscle. Toxicological assessment of Cd and Pb concentrations was performed using the maximum limits set by the European Commission Regulations 1881/2006 and 629/2008 for muscle tissue (50 and 300 μg/kg wet wt, respectively). The concentrations of Cd and Pb in muscle detected in the present study for all the analyzed examples of M. surmuletus and P. prayensis were lower than the maximums established for muscle tissue by European legislation. Therefore, consumption of the muscle of these fish is considered safe in terms of Al, Cd, and Pb concentrations. However, the consumption of liver tissue should be avoided because of its high levels of metals. Constant monitoring of the concentrations of metals of toxicological concern in fish products available in the market is an essential part of food safety.

The concentrations of three toxic heavy metals, mercury (Hg), lead (Pb), and cadmium (Cd), were determined in preserved variegated scallops (Chlamys varia, Bivalvia, Mollusca), which are often consumed in Tenerife (Canary Islands, Spain). A total of 300 samples of seven commercial brands (A, B, D, H, J, L, and M) and one processed product ("scallop sauce") were analyzed. Samples were collected weekly in a major shopping area in Santa Cruz de Tenerife during a 12-month period. The concentrations of lead and mercury were far below the maximum limit permitted for human consumption by the European Communities Commission regulation (EC) 466/2001 (1 and 0.5 mg kg(-1) wet weight for Pb and Hg, respectively). Concentrations of cadmium were close to the maximum limit permitted by regulation (EC) 466/2001 (1 mg kg(-1) wet weight).

Concentrations of mercury were determined for tinned molluscs (Mollusca, Bivalvia), i.e., mussels (Mytilus spp.), cockles (Cerastoderma edule), variegated scallops (Chlamys varia), and razor shells (Ensis spp.), consumed in Spain. A total of 220 samples were analyzed: 120 mussels, 40 cockles, 24 variegated scallops, and 36 razor shells. Samples were obtained weekly from markets in Santa Cruz de Tenerife (Canary Islands) over a period of 12 months. All observed concentrations of mercury were below the maximum permitted for human consumption (0.5 mg/kg) as defined by European Community Decision 93/ 351/CE. Mercury concentrations were 27.28 +/- 12.43 microg/kg for mussels, 66.59 +/- 23.53 microg/kg for cockles, 33.68 +/- 15.76 microg/kg for variegated scallops, and 21.26 +/- 12.24 microg/kg for razor shells. To evaluate the importance of mercury as a food contaminant, the percentage ingested daily, the weight of mercury in the diet, and the calculated percentage of this metal in the diet contributed by reference species were estimated.

Concentrations of three toxic heavy metals (Hg, Pb, Cd) and six essential heavy metals (Fe, Zn, Mn, Cr, Cu, Ni) were determined in mussel conserves (Mytilus galloprovincialis, Bivalvia, Mollusca) consumed habitually by individuals in Tenerife (Canary Islands, Spain). A total of 600 samples were analyzed, corresponding to six different commercial brands and four different processing types: pickled sauce (mixture of olive oil, vinegar, red pepper, laurel, and salt), coquille St. Jacques sauce (coquille St. Jacques broth), nature (water and salt), and bionature (water, salt, and soluble vegetal fiber). Samples were collected weekly from markets in Santa Cruz de Tenerife during a 12-month period. All values for toxic metals were lower than the permitted maximum for human consumption as proscribed in European Community Directive 2001/22/CE (1,000 microg/kg wet weight for Pb and Cd) and European Community Decision 93/351/EEC (500 microg/kg wet weight for Hg). For the six essential heavy metals, mussels are a very good source, contributing high percentages of the recommended daily allowance.