Atmospheric mercury (Hg) in the Adirondacks: concentrations and sources

Hourly averaged gaseous elemental Hg (GEM) concentrations and hourly integrated reactive gaseous Hg (RGM), and particulate Hg (Hg(p)) concentrations in the ambient air were measured at Huntington Forest in the Adirondacks, New York from June 2006 to May 2007. The average concentrations of GEM, RGM, and Hg(p) were 1.4 +/- 0.4 ng m(-3), 1.8 +/- 2.2 pg m(-3), and 3.2 +/- 3.7 pg m(-3), respectively. RGM represents < 3.5% of total atmospheric Hg or total gaseous Hg (TGM: GEM + RGM) and Hg(p) represents < 3.0% of the total atmospheric Hg. The highest mean concentrations of GEM, RGM, and Hg(p) were measured during winter and summer whereas the lowest mean concentrations were measured during spring and fall. Significant diurnal patterns were apparent in warm seasons for all species whereas diurnal patterns were weak in cold seasons. RGM was better correlated with ozone concentration and temperature in both warm (rho (RGM - ozone) = 0.57, p < 0.001; rho (RGM - temperature) = 0.62, p < 0.001) and cold seasons (rho (RGM - ozone) = 0.48, p = 0.002; rho (RGM - temperature) = 0.54, p = 0.011) than the other species. Potential source contribution function (PSCF) analysis was applied to identify possible Hg sources. This method identified areas in Pennsylvania, West Virginia, Ohio, Kentucky, Texas, Indiana, and Missouri, which coincided well with sources reported in a 2002 U.S. mercury emissions inventory.     

The Use of principal component analysis (PCA) for evaluating results from pig meat quality measurements

The relationships between different meat quality methods, i.e. pH, meat colour, protein extractability and pigment content, measured on Swedish pig carcasses, were analysed by principal component analysis (PCA). The result indicated that when using PCA for selection among the meat quality methods used, the ultimate internal reflectance explained the greatest proportion of the total variance. The results of this study show that PCA is a simple method of finding objects with different characteristics (e.g. outliers and various quality classes) and for variable selection.     

河北省2010年至2019年小麦质量监测数据统计分析

为了给小麦收储企业和加工企业提供河北省小麦质量信息,对合理利用当地小麦资源提供技术依据,对2010年至2019年河北省小麦主产区的新收获小麦进行容重、千粒重、不完善粒含量、生芽粒含量、水分、硬度指数、降落数值、湿面筋含量以及蛋白质含量等品质质量指标的分析,从各检测指标的年度变化、各市检测指标平均值比较和检测指标优选比较...     

Residues of lead,cadmium, mercury and tin in canned meat products from Egypt: an emphasis on permissible limits and sources of contamination

In an attempt to determine the residual levels of lead (Pb), cadmium (Cd), mercury (Hg) and tin (Sn) in canned meat products marketed in Egypt, a total number of 160 random samples (40 each) of canned chicken luncheon (CCL), canned beef luncheon (CBL), canned frankfurter (CF) and canned corned beef (CCB) were randomly collected from different supermarkets in Egypt to be analyzed using atomic absorption spectrophotometry. From the obtained results, it was found that the mean values of residual levels of Pb in examined CCL, CBL, CF and CCB samples were 0.330, 0.224, 0.206 and 0.334 mg/kg, respectively, while those of Cd were 0.057, 0.053, 0.039 and 0.042 mg/kg, those of Hg were 0.387, 0.450, 0.402 and 0.332 mg/kg, and finally those of Sn were 2.061, 2.308, 0.755 and 1.997 mg/kg. The obtained results were compared with the permissible limits of heavy metals recommended by international and national authorities. In addition, the public health significance as well as the sources of contamination of canned meat products by heavy metals were addressed.     

罗非鱼酶解液中挥发性成分分析

采用顶空- 固相微萃取(HS-SPME)技术结合气相色谱- 质谱联用(GC-MS)对罗非鱼蛋白酶酶解液中挥发性成分进行研究,优化顶空固相微萃取的条件,并对挥发性成分进行鉴定和分析。结果表明最佳萃取条件为样品中添加30g/100mL 氯化钠,采用以聚二甲基硅氧烷/ 二乙烯基苯(PDMS/DVB)为涂层的萃取头在60℃条件下搅拌萃取40min。实验共鉴定出69种挥发性物质,其中与罗非鱼酶解液气味相关的成分主要是相对分子质量为80～200的C6～C9 挥发性羰基化合物、醇类和含氮类物质,这些挥发性成分的协同作用构成了酶解液的特征风味。     

Continuous analysis of dissolved gaseous mercury (DGM) and mercury flux in two freshwater lakes in Kejimkujik Park,Nova Scotia: evaluating mercury flux models with quantitative data

Diurnal patterns for dissolved gaseous mercury (DGM) concentration, mercury flux, several water variables (pH, oxidation reduction potential (ORP), water temperature), and meteorological variables (wind speed, air temperature, % relative humidity, solar radiation) were measured in two lakes with contrasting dissolved organic carbon (DOC) concentrations in Kejimkujik Park, Nova Scotia. A continuous analysis system made it possible to measure quick changes in DGM over time. Consistently higher DGM concentrations were found in the high DOC lake as compared to the low DOC lake. An examination of current mercury flux models using this quantitative data indicated some good correlations between the date and predicted flux (r ranging from 0.27 to 0.83) but generally poor fit (standard deviation of residuals ranging from 0.97 to 3.39). Cross-correlation analysis indicated that DGM dynamics changed in response to solar radiation with lag-times of 65 and 90 min. This relationship with solar radiation was used to develop new predictive models of DGM and mercury flux dynamics for each lake. We suggest that a generalized approach using time-shifted solar radiation date to predict DGM can be incorporated into existing mercury flux models. It is clear from the work presented that DOC and wind speed may also play important roles in DGM and mercury flux dynamics, and these roles have not been adequately accounted for in current predictive models.     

Content of toxic heavy metals (mercury, lead, and cadmium) in canned variegated scallops (Chlamys varia)

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).     

虎纹蛙肌肉挥发性成分和脂肪酸分析

对虎纹蛙肌肉中的挥发性成分和脂肪酸分别进行测定。采用顶空固相微萃取-气相色谱-质谱联用技术(HS-SPME-GC-MS)分析虎纹蛙肌肉中的挥发性成分。结果共鉴定出36种成分,其中醛类化合物有15种,且含量最高,占挥发性成分总量的68.76%;己醛、(Z)-4-庚烯醛、(E,Z)-2,4-癸二烯醛、(E,E)-2,4-癸二烯醛、1-辛烯-3-醇和2,3-戊二酮等可能对虎纹蛙肉的整体风味贡献较大;虎纹蛙肌肉脂肪酸主要由不饱和脂肪酸(UFA)组成,占脂肪酸总量的72.89%;在日常饮食中,虎纹蛙肉为n-3多不饱和脂肪酸(n-3 PUFA)较为丰富的食物资源;亚麻酸(C18:3 n-3,ALA)、二十碳五烯酸(C20:5 n-3,EPA)和二十二碳六烯酸(C22:6 n-3,DHA)为主要的n-3 PUFA。UFA为虎纹蛙肉的重要风味前体物质。     

Mercury speciation in the muscle of two commercially important fish,hake (Merluccius merluccius) and striped mullet (Mullus barbatus) from the Mediterranean sea: estimated weekly intake

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.     

无花果不同部位中的营养成分分析

采用不同方法对无花果的枝、叶及果分别进行成分提取、测定了提取物中苯甲醛（紫外双波长法）、硒元素（比色法）、糖（高效液相色谱法）和蛋白质（凯氏定氮法）的含量。结果表明：苯甲醛和硒在叶中的含量最高；蛋白质在不同部位的含量均以水提取物为最高；糖的含量与其分子量大小及无花果的不同部位有关。这说明无花果的枝、叶及果均具有较高的食用和药用价值。以上研究结果为进一步综合开发利用无花果提供了实验依据。     

Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): importance of atmospheric deposition and ecosystem factors

Concentrations of methylmercury in game fish from many interior lakes in Voyageurs National Park (MN, U.S.A.) substantially exceed criteria for the protection of human health. We assessed the importance of atmospheric and geologic sources of mercuryto interior lakes and watersheds within the Park and identified ecosystem factors associated with variation in methylmercury contamination of lacustrine food webs. Geologic sources of mercury were small, based on analyses of underlying bedrock and C-horizon soils, and nearly all mercury in the 0- and A-horizon soils was derived from atmospheric deposition. Analyses of dated sediment cores from five lakes showed that most (63% +/- 13%) of the mercury accumulated in lake sediments during the 1900s was from anthropogenic sources. Contamination of food webs was assessed by analysis of whole, 1-year-old yellow perch (Perca flavescens), a regionally important prey fish. The concentrations of total mercury in yellow perch and of methylmercury in lake water varied substantially among lakes, reflecting the influence of ecosystem processes and variables that affect the microbial production and abundance of methylmercury. Models developed with the information-theoretic approach (Akaike Information Criteria) identified lake water pH, dissolved sulfate, and total organic carbon (an indicator of wetland influence) as factors influencing methylmercury concentrations in lake water and fish. We conclude that nearly all of the mercury in fish in this seemingly pristine     

2017~2019年日照市市售海带中铅、镉、汞、砷、无机砷污染监测分析

目的 调查日照市市售海带中常见污染物铅、镉、汞、砷、无机砷污染的含量,为市售海带的深加工与安全风险评价提供基础资料与科学依据。方法 在市直、县区各农贸市场、超市、食堂等进行随机采样,用电感耦合等离子体质谱仪(ICP-MS)测定市售海带中铅、镉、汞、砷的含量,以液相色谱-原子荧光光谱仪测定无机砷的含量,并按照湿、淡干、盐干等三种海带样品进行分类,对检测结果进行比较分析。 结果 2017～2019年日照市市售海带样品按照湿、淡干、盐干分类,三类样品中铅、镉、汞、砷及无机砷的含量在不同年度之间具有一致性。在同一年度中,铅、镉、砷含量的平均值：湿<盐干<淡干；汞含量平均值：湿<盐干、淡干,盐干、淡干样品中汞含量无显著差异；湿样品无机砷含量均合格,而淡干、盐干样品合格率偏低。结论 海带中铅、镉、汞、砷、无机砷污染普遍存在,而在湿、淡干与盐干海带中铅、镉、汞、砷、无机砷含量的差别应在监管与安全风险评估中给予重视。     

Contents of cadmium, copper, mercury and lead in fish from the Neretva river (Bosnia and Herzegovina) determined by inductively coupled plasma mass spectrometry (ICP-MS)

The concentrations of cadmium, copper, mercury and lead in fish from the Neretva river have been investigated in order to assess safety for consumers and the level of contamination. Samples of muscle and liver from six fish species (brown trout, common carp, prussian carp, chub, rudd and gray mullet) were collected at six locations upstream and downstream from the three largest towns along the Neretva river. Metal concentrations were determined by inductively coupled plasma mass spectrometry after microwave-assisted acid mineralisation. Accumulation of metals in fish tissues was species-dependent. The average content of metals in fish muscle samples was 0.013-0.055, 0.068-16.059, 0.050-0.401 and 0.055-0.703 mg/kg for Cd, Cu, Hg and Pb, respectively. Health effects due to fish consumption could not be excluded. Further investigation is recommended, including a survey of fish consumption frequency among the local inhabitants and sports fishermen.     

Content of mercury and cadmium in fish (Thunnus alalunga) and cephalopods (Eledone moschata) from the south-eastern Mediterranean Sea

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.     

我国主要金柑品种果皮中挥发性成分比较

基于顶空固相微萃取-气相色谱-质谱联用技术,比较我国15 个金柑品种果皮中主要挥发性物质的种类和含量差异。15 个金柑品种累计检出195 种挥发性物质,各品种果皮检出组分数变幅为45～78;总含量变化幅度为791.69～27 405.95 μg/g,变异系数为46.46%;包括烃类、醇类、醛类、酮类和酯类;主要成分为柠檬烯、月桂烯、松油烯、萜品烯、异柠檬烯、异松油烯、左旋-α-蒎烯、γ-榄香烯、丁香烯、吉马烯、α-紫穗槐烯、芳樟醇等物质,不同金柑品种间累计特有成分55 种。利用R软件数据统计结合主成分分析,基于挥发性物质对金柑品种进行了统计学分析,结果显示我国金柑挥发性物质种类和含量丰富,差异显著,可以作为区分不同金柑的辅助工具。     

Biogeographic provinces of total and methyl mercury in zooplankton and fish from the Beaufort and Chukchi seas: results from the SHEBA drift

Samples of copepods (Calanus hyperboreus) and arctic cod (Boreogadus saida) were collected along the SHEBA (Surface HEat Budget of the Arctic) drift track, which commenced in the Canada Basin (October 1997) and finished in the Mendeleev Basin (October 1998). Here, we report total mercury (HgT) and CH3Hg concentrations in these biological samples and examine concentration variability along the drift track in the context of trophic variation, inputs from land, spring mercury depletion events (MDEs), and oceanographic provinces. We find background concentrations of HgT in C. hyperboreus as low as 0.02 microg/g (dw), with the Canada Basin samples exhibiting approximately 2-fold higher mercury concentrations than those from the Chukchi Plateau and Mendeleev Abyssal Plain. This east-to-west trend in mercury concentration is punctuated by two and possibly three intervals of elevated mercury (HgT, 0.10-0.12 microg/g (dw); CH3Hg, 0.023-0.028 microg/g (dw)) along the drift track. One interval of elevated HgT and CH3-Hg levels occurred during and shortly after melt. %CH3Hg reached a maximum of 60% during this time period, three times higher than any other time during the drift. This transient rise in C. hyperboreus CH3Hg concentration seems to strongly point to mercury accumulated in snow during MDEs. However, the alignment of elevated mercury samples with oceanographic fronts and the observed regional differences between basins suggest that variation of mercury concentration is primarily a consequence of ocean structure. Given that large animals such as whales selectively forage in regions of higher food concentration such as fronts, recent change in the ice climate of the western Arctic Ocean, perhaps mediated by changes in heat storage, may provide the means to change their exposure to mercury thus explaining observed increases in mercury concentrations in western beluga whales during the 1990s.     

米团花色素提取前后的主要成分变化分析

研究乙醇提取色素后花中主要成分的变化,为残渣的综合利用提供参考。结果表明,米团花中还原糖、蛋白质、粗纤维和灰分含量分别为11.35%、14.32%、25.47%和5.79%。提取色素(60%的乙醇)后,还原糖几乎全部被浸出,灰分含量显著下降,其中以钾、钙、磷下降最为明显;蛋白质和粗纤维因不溶于乙醇溶液而得到富集,含量显著升高,重金属含量符合国家饲料卫生标准,说明色素提取后的残渣可作为优质饲料。     

顶空固相微萃取-气相色谱-质谱联用法分析山楂果醋易挥发成分

采用顶空固相微萃取和气相色谱-质谱联用法对山楂果醋易挥发性成分进行提取分析,通过与NIST 05 a.L谱库比对,鉴定得到各个组分,应用峰面积归一化法测定各成分的相对含量。共分离得到49 种化合物,结构鉴定出36 种化合物,占总易挥发成分总量的98.91%,对山楂果醋易挥发性成分贡献较大的依次是：酯类化合物11 种,占40.12%;酸类化合物6 种,占33.63%;醇类化合物11 种,占21.79%。此外,醛类化合物1 种,占0.05%;酮类化合物2 种,占0.57%;其他类5 种,占1.55%。初步确定乙酸、乙酸乙酯、乙醇、乙酸-3-甲基丁酯、苯甲酸乙酯、3-甲基丁醇、己酸乙酯、己酸、苯甲酸、乙酸-1-甲基丙酯、2-丁醇、苯乙醇、辛酸、2-甲氧基-4-甲基苯酚是山楂果醋的主要香气成分。以期为山楂果醋的香气特征研究提供科学依据,为山楂果醋品质感官评价体系的建立和山楂果醋产业发展提供参考。