首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
Total mercury was measured in the edible portions of 244 selected fish and shellfish purchased in Canada at the retail level. By species, average mercury concentrations ranged from 0.011 μg g-1 for oysters to 1.82 μg g-1 for swordfish. The predatory fish contained the highest concentrations of mercury: swordfish (mean 1.82 μg g-1, range 0.40-3.85 μg g-1), marlin (1.43, 0.34-3.19 μg g-1), shark (1.26, 0.087-2.73 μg g-1), and canned, fresh and frozen tuna (0.35, 0.020-2.12 μg g-1). Levels of mercury in the fresh and frozen tuna contained a mean of 0.93 μg g-1 (range 0.077-2.12 μg g-1) and were substantially higher than in the canned tuna (0.15, 0.02-0.59 μg g-1). In the canned tuna, mercury concentrations varied with subspecies, with the highest average concentrations being found in Albacore tuna (mean 0.26 μg g-1, range 0.19-0.38 μg g-1) and the lowest (0.047, 0.025-0.069 μg g-1) in five samples for which the subspecies of tuna were not identified. Mean concentrations of mercury in swordfish and fresh and frozen tuna were up to three times higher than reported for the USA. Dietary intake estimations found that provided fresh and frozen tuna, marlin, swordfish or shark are consumed once a month or less, the dietary intakes of total mercury by women of child-bearing age, averaged over 1 month, would fall below the Joint FAO/WHO Expert Committee on Food Additives provisional tolerable weekly intake for total mercury. The current Canadian advisory to children and women of child-bearing age is to limit their consumption of fresh and frozen tuna, swordfish and shark to no more than one meal per month.  相似文献   

2.
Mercury and cadmium concentrations were measured in the flesh and liver (or hepatopancreas) of albacore (Thunnus alalunga) and horned octopus (Eledone moschata) to establish whether the concentrations exceeded the maximum levels fixed by the European Commission. In both species, mercury and cadmium mean concentrations were higher in liver (albacore: mercury = 2.41 μg g-1 wet wt, cadmium = 9.22 μg g-1 wet wt; horned octopus: mercury = 0.76 μg g-1 wet wt, cadmium = 6.72 μg g-1 wet wt) than in flesh (albacore: mercury = 1.56 μg g-1 wet wt, cadmium = 0.05 μg g-1 wet wt; horned octopus: mercury = 0.36 μg g-1 wet wt, cadmium = 0.33 μg g-1). Mercury concentrations exceeding the prescribed legal limit of 1 μg g-1 wet wt were found in almost all albacore samples (flesh: 71.4%; liver: 85.7%). For horned octopus, concentrations above 0.5 μg g-1 wet wt were observed solely in hepatopancreas, while in flesh, the concentrations were below this limit in all the samples examined. Of the flesh samples of albacore, 42.8% exceeded the proposed tolerance for cadmium for human consumption, whilst for horned octopus, the established limit was not exceeded in any sample.  相似文献   

3.
Cadmium and mercury in cephalopod molluscs: Estimated weekly intake   总被引:3,自引:0,他引:3  
Cadmium and mercury concentrations were measured in the flesh and hepatopancreas of different species of cephalopod molluscs (European squid, common octopus, curled octopus, horned octopus, pink cuttlefish, common cuttlefish) in order to establish whether the concentrations exceeded the maximum levels fixed by the European Commission. In hepatopancreas, the levels of cadmium were substantially higher than those in flesh (flesh 0.11-0.87 µg g-1 wet weight, hepatopancreas 2.16-9.39 µg g-1 wet weight), whilst the levels of mercury (flesh 0.13-0.55 µg g-1 wet weight, hepatopancreas 0.23-0.79 µg g-1) were approximately double those in flesh. Concentrations exceeding the maximum permitted limit of cadmium were found in 39.8 and 41.0% of common octopus and pink cuttlefish flesh, respectively. For mercury, concentrations above the limit were found only in octopuses, and precisely in 36.8, 50.0 and 20.0% of flesh samples of common, curled and horned octopus, respectively. In the hepatopancreas, concentrations of cadmium and mercury were above the proposed limits in all the samples examined. The estimated weekly intake of between 0.09 and 0.49 µg kg-1 body weight for cadmium and between 0.05 and 0.24 µg kg-1 body weight for mercury made only a small contribution to the provisional tolerable weekly intake (cadmium 1.3-7.0%, mercury 1.0-4.8%) set by the WHO.  相似文献   

4.
Coastal populations with high seafood consumption in the Mediterranean have a significant exposure to dietary methylmercury, and areas where environmental mercury pollution is an issue due to industrial activities are of special concern. The study was undertaken with the aim of assessing methylmercury exposure through fish consumption in a community of north Morocco and characterizing the relevant health risk. Concentrations of total mercury were determined in human hair, a biomarker of methylmercury exposure, and in locally consumed fish by cold vapour atomic absorption spectrophotometry. Based on consumption frequencies reported by the 108 subjects included in the study the weekly intake of methylmercury was estimated and biomarker data were evaluated in relation to the estimated intake and the sociodemographic characteristics of the population. Multiple regression analysis was employed for the interpretation of hair mercury data in relation to fish consumption frequency, gender and the age of individuals. Mercury concentrations in hair ranged from 0.22 to 9.56 µg g-1 (geometric mean = 1.79 µg g-1) and were closely related to fish intake. Fisherman and their families consumed fish three to five times per week and were the most exposed population subgroup. A high proportion of women of child-bearing age (50%) had relatively high levels of mercury in their hair (3.08-7.88 µg g-1).  相似文献   

5.
The mercury content of 25 samples of fish and seafood products most frequently consumed in Spain was determined. A simple method comprising cold vapour and atomic absorption spectrometry was used to determine separately inorganic and organic mercury. In all samples inorganic mercury content was below 50 µg kg-1. There was wide variability, among not only the mercury levels of different fish species, but also for different samples of the same species — with the methylmercury content ranging from below 54 to 662 µg kg-1. The highest mean methylmercury content was found in fresh tuna. Based on an average total fish consumption of 363 g/person week-1, the methylmercury intake was estimated to be 46.2 µg/person week-1. Therefore, the mercury intake of Spanish people with a body weight ≤ 60 kg is lower than the Joint FAO/WHO Expert Committee on Food Additives (JECFA) provisional tolerable weekly intake (PTWI) of 1.6 µg kg-1 body weight, but exceeds the US National Research Council (NRC) limit of 0.7 µg kg-1 body weight week-1 based on a benchmark dose.  相似文献   

6.
Total mercury was measured in 259 total diet food composites from two Canadian cities. Levels were generally low, with 46% of the composites having concentrations below the limit of detection, which ranged from 0.026 to 0.506 ng g-1. The fish category contained the highest mercury concentrations, which averaged 67 ng g-1 and ranged from 24 to 148 ng g-1. All composites were below the Canadian guideline for total mercury in fish of 0.5 ppm. Dietary intakes of mercury averaged 0.022 μg kg-1 body weight/day (μg kg-1 day-1), and ranged from 0.012 μg kg-1 day-1 for females over 65 years old to 0.062 μg kg-1 day-1 for 0-1-month-old infants. For fish consumers, fish contributed to more than half of the ingested mercury. All intakes were well below Joint FAO/WHO Expert Committee on Food Additives Provisional Tolerable Weekly Intakes, expressed on a daily basis, of 0.71 μg kg-1 day-1 total mercury and 0.47 μg kg-1 day-1 methyl mercury, and also below a recent Health Canada recommended maximum methyl mercury intake of 0.2 μg kg-1 day-1 for children and women of child-bearing age.  相似文献   

7.
Total mercury concentrations were measured in the muscle of different kinds of fish: megrim (Lepidorhombus boscii), common sole (Solea vulgaris), striped mullet (Mullus barbatus), anglerfish (Lophius piscatorius), and black-bellied angler (Lophius budegassa  相似文献   

8.
The occurrence of deoxynivalenol (DON) in Danish wheat flour was studied during the period 1998-2003 by either capillary gas chromatography with electron capture detection and liquid chromatography coupled to an ion trap mass spectrophotometer. A total of 151 samples were collected from mills and the retail market in Denmark. Contamination levels varied considerably from year-to-year with the highest concentrations occurring in samples from the 2002 harvest with mean and median concentrations of 255 and 300 µg kg-1, respectively. Compared to other harvest years, 2002 had the highest amount of precipitation around flowering time, i.e. from the end of June to the beginning of July covering weeks 25-27. The lowest average levels were found in samples from the 2001 harvest, where weeks 25-27 were dry compared with other harvest years. The highest value (705 µg kg-1) was obtained in a flour sample from the 2002 harvest, but none of the tested samples exceeded the maximum limit of 750 µg kg-1, which has been recently introduced by the European Commission for DON in flour used as raw materials in food products. Calculation of chronic or usual intake by a deterministic approach showed that intake did not exceed the TDI of 1 µg kg-1 bw day-1 either for the whole population or for children. A probabilistic approach also showed that intake in general was below the TDI, but intake for children in the 99% percentile amounted to more than 75% of the TDI. The highest intake is calculated to be 2.5 µg kg-1 bw day-1.  相似文献   

9.
The production of β-carotene from a synthetic medium by Blakeslea trispora in fed-batch culture was investigated. A maximum β-carotene concentration of 85.0 mg L-1 with productivity of 0.16 mg L-1 h-1 and specific β-carotene production rate of 0.01 mg g-1 h-1 was obtained by feeding the cells constantly with olive oil, cottonseed oil, soybean oil, antioxidant, and low concentration of growth factors at feeding rate of 4.2 mL h-1 from the beginning of the fermentation. In this case, the fed-batch culture supported high values of biomass dry weight (11.0 g L-1) and sugar utilization (0.976 g g-1). The morphology of the fungus was studied during growth in fed-batch fermentation system using an image analysis system. Zygospores are the morphological forms, which are responsible for the production of the pigment. The highest percentage of zygospores (11.44%) was correlated with the highest percentage of intracellular β-carotene (0.72%) in the total biomass dry weight. Moreover, high percentages of vacuolated hyphae, evacuated cells, and degenerated hyphae of the microorganism were observed. This was due to the formation of high amount of H2O2 by exposure of the microorganism to high dissolved oxygen concentration.  相似文献   

10.
Polyethylene terephthalate (PET) is frequently used as a packaging material for beverage bottles, fruit and vegetable trays, and egg crates in Japan. Levels of formaldehyde (FA), acetaldehyde (AA) and PET oligomers in various PET food packaging were determined. PET samples were initially dissolved in trifluoroacetic acid with 2,4-dinitrophenylhydrazine to derivatize formaldehyde and acetaldehyde to their dinitrophenylhydrazones. The stable derivatives along with the oligomers were analysed using HPLC with ultraviolet light detection at 360 and 254 nm, respectively. The PET pellets contained 3.5-12.4 µg g-1 AA and 4.0-7.2 mg g-1 oligomers, while FA was below the determination limit. FA, AA and oligomer levels in Japanese bottles were 0.6-3.0 µg g-1, 8.4-25.7 µg g-1 and 5.0-8.7 mg g-1, ND-1.6 µg g-1, 5.0-13.1 µg g-1 and 4.9-8.2 mg g-1 in French and Italian bottles, and ND-1.2 µg g-1, 9.1-18.7 µg g-1 and 5.6-8.0 mg g-1 in US and Canadian bottles, respectively. Compared with European bottles, Japanese bottles contain higher FA and AA levels. In sheet-moulding products, their contents were determined as ND-1.1 µg g-1, 11.5-43.1 µg g-1 and 4.6-9.2 mg g-1, respectively. The results show that sheet-moulding products contain lower FA and higher AA in comparison with bottles. FA and AA are considered to be generated from PET during the heating process for moulding the pellets to bottles or sheet-moulding articles and de-aeration during the sheet-moulding process is effective in removing FA. In contrast, the level of the oligomers remains unchanged during the moulding process from pellets to bottles or sheet products.  相似文献   

11.
Estimations of ochratoxin A (OTA) and 4-deoxynivalenol (DON) exposure of the Belgian population through beer consumption were made using the results of the recent Belgian food survey and the compiled data set of OTA and DON levels in conventionally and organically produced beers in 2003-05. For the consumers of organic beers, the daily intake of OTA was 0.86 (in 2003), 1.76 (in 2004) and 0.72 (in 2005) ng kg-1 body weight (bw), considering the mean beer consumption (0.638 litres) and the average level of OTA in 2003, 2004 and 2005, respectively. Using the 97.5th percentile of beer consumption (1.972 litres), the corresponding OTA daily intakes were 2.65, 5.44 and 2.24 ng kg-1 bw, which are close or above the tolerable daily intake (TDI) of 5 ng kg-1 bw. For the consumers of conventional beers, the OTA intakes were low: 0.23, 0.23 and 0.11 ng kg-1 bw day-1 for the average beer consumption, in 2003, 2004 and 2005 against 0.72, 0.73 and 0.34 ng kg-1 bw day-1 when the 97.5th percentile level was considered. As for the DON intake, the estimates were quite low for both conventional and organic beer consumers when the provisional maximum TDI (PMTDI) of 1 µg kg-1 bw was considered. Average consumption of organic beer led to daily intakes of 0.05 and 0.04 µg DON kg-1 bw in 2003 and 2004, respectively, whilst for conventional beer, daily intakes were 0.07 and 0.05 µg DON kg-1 bw. At the 97.5th percentile level of beer consumption, daily intakes of 0.15 and 0.13 µg kg-1 bw were obtained for organic beers against 0.23 and 0.17 µg kg-1 bw for conventional ones. The results showed that beer could be an important contributor to OTA exposure in Belgium, even though a declining trend seems to be apparent during the last year of monitoring. Therefore, efforts should be devoted to maintain the OTA levels as low as reasonably achievable, especially for organic beer.  相似文献   

12.
The use of silver foils in various food preparations is a common practice in Middle Eastern and South East Asian countries. The FAO/WHO Joint Expert Committee on Food Additives (JECFA) has included silver in the list of food additives, but specifications were not prepared. Indian food legislation has included food-grade silver foil and laid down a purity requirement of 99.9%. This leaves an unspecified margin of 0.1% or 1000 µg g-1 for contaminants. Therefore, a study to investigate the levels of metallic contaminants in food-grade silver foil was undertaken. Of 178 foils analysed, 161 (90%) contained silver, whilst 10% were fraudulently made up of aluminium. In the case of silver foils, 46% of the samples adhered to the desired purity requirement of 99.9%, while 54% had a lower silver content. Copper was present in 86.3% of the silver foils, while chromium, nickel and lead contamination was found in over 54% of samples. Cadmium levels were detected in 28% of the silver foils and manganese was present in 6.8% of samples. In silver foils showing metal contaminants, average levels were found for nickel (487 µg g-1), lead (301 µg g-1), copper (324 µg g-1), chromium (83 µg g-1), cadmium (97 µg g-1) and manganese (43 µg g-1), which being appreciable justify the need to prescribe limits for some metals in food-grade silver foil as well as for silver powder used in confectioneries and medicinal preparations. The work reported here should encourage manufacturers to use high-purity raw materials and take suitable precautions to reduce unwarranted exposure of consumers to toxic metal contaminants.  相似文献   

13.
Australian survey of acrylamide in carbohydrate-based foods   总被引:2,自引:0,他引:2  
A method was developed and validated for the determination of acrylamide in carbohydrate-based foods. Solid-phase extraction employing a mixed-bed anion and cation exchange cartridge in series with a C18 extraction disk was used to clean-up water extracts of food samples before analysis by liquid chromatography coupled with tandem mass spectrometry detection. The limit of detection was calculated as approximately 25 μg kg-1 and the limit of reporting was 50 μg kg-1. The average method recovery for 84 samples from a range of matrices reporting was 99% with a relative standard deviation of 11.2%. A survey was conducted of 112 samples of carbohydrate-based foods composited from 547 products available in the Australian market. The analytical results were used in conjunction with Australian food consumption data derived from the 1995 National Nutrition Survey (NNS) to prepare preliminary dietary exposure estimates of Australians to acrylamide through only the food groups examined. Mean dietary exposure to acrylamide resulting from consumption of the foods tested, for Australians aged 2 years and above, was estimated as 22-29 µg day-1 (equivalent to 0.4-0.5 µg kg-1 bodyweight day-1) and between 73 and 80 µg day-1 (1.4 and 1.5 µg kg-1 bodyweight day-1) for 95th percentile consumers. Young children (2-6 years) consuming acrylamide-containing foods had a higher acrylamide exposure on a per kilogram bodyweight basis (mean 1.0-1.3 µg kg-1 bodyweight day-1). The estimated exposure of Australians to acrylamide is similar to that estimated for other countries.  相似文献   

14.
《Food chemistry》2005,89(2):295-300
Total mercury and methylmercury concentrations were measured in the muscle tissue of two fish species from the Ionian and Adriatic seas. Higher total mercury and methylmercury concentrations were detected in striped mullet (Mullus barbatus), a benthic species (Ionian sea: Hg=0.40 μg g−1 wet wt, MeHg=0.40 μg g−1 wet wt; Adriatic sea: Hg=0.49 μg g−1 wet wt, MeHg=0.44 μg g−1 wet wt), than in hake (Merluccius merluccius), a pelagic species (Ionian sea: Hg=0.09 μg g−1 wet wt, MeHg=0.09 μg g−1 wet wt; Adriatic sea: Hg=0.18 μg g−1 wet wt; MeHg=0.16 μg g−1 wet wt). Total mercury residues were determined in all samples of both species from the Adriatic sea, while levels below the limit of detection were registered in 25% and 11%, respectively, of striped mullet and hake samples from the Ionian sea. In 18.8% and 22.2% of striped mullet samples from the Ionian and Adriatic seas, respectively, total mercury concentrations exceeded the maximum level fixed by the European Commission Decision (Hg=0.5 μg g−1 wet wt). In the two different species, mercury was present almost completely in the methylated form with mean percentages between 60% and 100%. The estimated weekly intake for total mercury was below the established the provisional tolerable weekly intake (PTWI) for both species, though their consumption provides a methylmercury intake above the WHO safety limit.  相似文献   

15.
Arsenic contamination of rice plants by arsenic-polluted irrigation groundwater could result in high arsenic concentrations in cooked rice. The main objective of the study was to estimate the total and inorganic arsenic intakes in a rural population of West Bengal, India, through both drinking water and cooked rice. Simulated cooking of rice with different levels of arsenic species in the cooking water was carried out. The presence of arsenic in the cooking water was provided by four arsenic species (arsenite, arsenate, methylarsonate or dimethylarsinate) and at three total arsenic concentrations (50, 250 or 500 µg l-1). The results show that the arsenic concentration in cooked rice is always higher than that in raw rice and range from 227 to 1642 µg kg-1. The cooking process did not change the arsenic speciation in rice. Cooked rice contributed a mean of 41% to the daily intake of inorganic arsenic. The daily inorganic arsenic intakes for water plus rice were 229, 1024 and 2000 µg day-1 for initial arsenic concentrations in the cooking water of 50, 250 and 500 µg arsenic l-1, respectively, compared with the tolerable daily intake which is 150 µg day-1.  相似文献   

16.
The migration characteristics of the UV stabilizer Tinuvin 234 (2-(2H-benzotriazol-2-yl)-4,6-bis (1-methyl-1-phenylethyl)phenol) into food simulants has been measured from polyethylene terephthalate (PET) using HPLC with UV detection. Ethanol/water, isooctane and a fractionated coconut oil simulant (Miglyol®) were used as food simulating solvents. The migration characteristics were measured at temperatures in the range of 40-70°C. Diffusion coefficients were determined to be in the range of 1 × 10-14 cm2 s-1 to 1 × 10-18 cm2 s-1. At 40°C, the amount of migration into 95% ethanol after 10 days was 2 μg dm-2. Isooctane is determined to be a good fatty food simulant that provides similar results for PET to those of fatty foods.  相似文献   

17.
The aim of this study was to determine the levels of lead and cadmium in chicken, pork, beef, lamb and turkey samples (both meat and meat products), collected in the island of Tenerife (Spain). Lead and cadmium were measured by graphite furnace atomic absorption spectrometry (GFAAS). Mean concentrations of lead and cadmium were 6.94 and 1.68 µg kg-1 in chicken meat, 5.00 and 5.49 µg kg-1 in pork meat, 1.91 and 1.90 µg kg-1 in beef meat and 1.35 and 1.22 µg kg-1 in lamb meat samples, respectively. Lead was below the detection limit in turkey samples and mean cadmium concentration was 5.49 µg kg-1. Mean concentrations of lead and cadmium in chicken meat product samples were 3.16 and 4.15 µg kg-1, 4.89 and 6.50 µg kg-1 in pork meat product, 6.72 and 4.76 µg kg-1 in beef meat product and 9.12 and 5.98 µg kg-1 in turkey meat product samples, respectively. The percentage contribution of the two considered metals to provisional tolerable weekly intake (PTWI) was calculated for meat and meat products. Statistically significant differences were found for lead content in meats between the chicken and pork groups and the turkey and beef groups, whereas for cadmium concentrations in meats, significant differences were observed between the turkey and chicken, beef and lamb groups. In meat products, no clear differences were observed for lead and cadmium between the various groups.  相似文献   

18.
Three hundred and twenty samples from the 1999 UK harvest comprising wheat (201 samples), barley (106) and oats (13) were analysed for ochratoxin A and deoxynivalenol. A small number of organic samples was also obtained. Samples were collected from farms, central stores, mills, maltings and ports from across the UK from February to April 2000. Ochratoxin A and deoxynivalenol analysis was by affinity column clean up and high-performance liquid chromatography with fluorescence and ultraviolet light detection, respectively, with limits of detection of 0.2 and 20 μg kg-1. The survey found ochratoxin A at below 5 μg kg-1 in 97% of the samples indicating satisfactory storage conditions. The remaining 3% of the samples contained ochratoxin A at levels between 5.2 and 231 μg kg-1, but none of these samples was intended for human consumption. Deoxynivalenol was detected in 88% of all samples, with 83% below 100 μg kg-1; the maximum level was 600 μg kg-1. Twenty samples containing deoxynivalenol at or above 150 μg kg-1 by high-performance liquid chromatography were all confirmed by gas chromatography/mass spectrometry. Nivalenol was also detected by gas chromatography/mass spectrometry at levels of 50 μg kg-1 or higher in 18 of 20 samples where deoxynivalenol was confirmed.  相似文献   

19.
A method for the simultaneous quantitative determination of deoxynivalenol (DON), fumonisin B1 (FB1) and zearalenone (ZEN) in maize by liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCIMS/MS), using stable isotopically labelled and structural analogues internal standards, is described. The procedure involves accelerated solvent extraction followed by two solid-phase clean-up steps on strong anion exchange resin and a Mycosep® column. Typical recoveries were calculated by spiking blank maize at three different concentrations for deoxynivalenol (200, 400 and 1000 μg kg-1) at 70%, for fumonisin B1 (100, 200 and 1000 μg kg-1) at 90%, and for zearalenone (50, 100 and 200 μg kg-1) at 40%. LC-APCIMS/MS analyses were realized in collision-induced dissociation on an ion-trap instrument to provide a high degree of selectivity and sensitivity. Extraction of ions from two transition reactions, monitored by LC-APCIMS/MS for each analyte, enabled a limit of detection for DON, FB1 and ZEN at, respectively, 10, 20 and 3 μg kg-1, and a limit of quantification at, respectively, 50, 50 and 10 μg kg-1. The robustness of the method was also evaluated with the analysis of wheat samples.  相似文献   

20.
A total of 226 swordfish samples collected from Taiwanese fishing vessels in the Indian and Atlantic oceans were examined for total mercury (THg) and organic Hg (OHg). Analysis of 56 pooled white muscle samples showed that THg and OHg concentrations ranged from 0.056 to 3.97 (1.3 ± 0.97) and from 0.043 to 3.92 (1.01 ± 0.82) µg g-1 flesh mass, respectively. These values were similar to those from various previous studies during the past three decades. THg and OHg were significantly linearly correlated with fork length (FL, cm) of the fish from Indian and Atlantic oceans; however, there was no significant OHg%-FL relationship. OHg and THg also were significantly correlated. Fishes with FL ≤ 140 cm met the methyl Hg (meHg) regulatory standard set by the European Commission Decision (meHg ≤ 1.0); and fish with FL ≤ 211 cm met the Taiwanese Food and Hygiene Standard (meHg ≤ 2.0). Weekly swordfish consumption rates and amounts are recommended accordingly.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号