Multivariate data analysis of some xenobiotic trace metals in mussels from the gulf of Trieste

The concentration of Cd, Hg and Pb in the soft part of mussels has been studied by means of bi- and multi-variate statistical approaches. In particular, the principal component analysis has been applied to study the association among these toxic metals in mussels sampled from the gulf of Trieste, which is a critical area as far as mercury pollution is concerned.     

Heavy metals at trace level in edible mussels (Mytilus galloprovincialis Lamarck) from the gulf of Trieste

The concentration of heavy metals (cobalt, nickel, copper, cadmium, mercury and lead), which are present at trace levels in the edible part of mussels (Mytilus galloprovincialis Lamarck) from hatcheries in the gulf of Trieste, is normally or log-normally distributed, according to a statistical test sensitive to asymmetry of the distribution. A log-normal distribution appears valid for describing nearly all trace metals, in particular toxic heavy metals like cadmium, mercury and lead. The frequency distribution of these metals has nearly the same asymmetry, although the one-way analysis of the variance shows that sample means come from different population means characterising the particular hatchery.     

Multivariate data analysis of some xenobiotic trace metals in mussels from the Gulf of Trieste

Summary The concentration of Cd, Hg and Pb in the soft part of mussels has been studied by means of bi-and multi-variate statistical approaches. In particular, the principal component analysis has been applied to study the association among these toxic metals in mussels sampled from the gulf of Trieste, which is a critical area as far as mercury pollution is concerned.

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Mehrdimensionale Analyse der Daten einiger xenobiotischer Spurenmetalle in Miesmuscheln aus dem Golf von Triest

Zusammenfassung Der Gehalt von Cd, Hg und Pb in Miesmuschelfleisch wurde nach einer statistischen mehrdimensionalen Analyse untersucht. Besonders wurde die Hauptkomponentenanalyse zum Studium der Assoziationen dieser toxischen Metalle in Miesmuscheln angewandt. Die Miesmuschelproben stammten aus dem Golf von Triest, ein kritisches Gebiet für Quecksilberverunreinigungen.

     

Principal component analysis for the identification of pollution sources in mussel survey by trace metals

Principal component analysis has been applied to analyze the correlation matrix obtained from a 8 X 43 data matrix. The 8 trace metals are Mn, Co, Ni, Cu, Zn, Cd, Hg, Pb, which are contained in the soft part of mussels (Mytilus galloprovincialis Lamarck). Mussels were sampled from two sites in the Gulf of Trieste. In both samples, 76-78% of the total variance is explained by the four principal components. The orthogonally rotated factor matrix indicates that Co and Ni are bonded to the first principal component and Cd and Pb to the first (site 2) or second principal component (site 1). The origin of trace metals in the soft part of mussels from the Gulf of Trieste is discussed.     

Principal component analysis for the identification of pollution sources in mussel survey by trace metals

Summary Principal component analysis has been applied to analyze the correlation matrix obtained from a 8 × 43 data matrix. The 8 trace metals are Mn, Co, Ni, Cu, Zn, Cd, Hg, Ph, which are contained in the soft part of mussels (Mytilus galloprovincialis Lamarck). Mussels were sampled from two sites in the Gulf of Trieste. In both samples, 76–78% of the total variance is explained by the four principal components. The orthogonally rotated factor matrix indicates that Co and Ni are bonded to the first principal component and Cd and Pb to the first (site 2) or second principal component (site 1). The origin of trace metals in the soft part of mussels from the Gulf of Trieste is discussed.

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Analyse der Hauptkomponenten zur Identifizierung der Verunreinigungsursachen von Muscheln über die Spurenmetalle

Zusammenfassung Die Analyse der Hauptkomponenten wurde auf die Korrelationsmatrix, die aus der 8 × 43-Datenmatrix hervorgeht, angewandt. Diese 8 Spurenmetalle sind Mn, Co, Ni, Cu, Zn, Cd, Hg, Pb, die im Fleisch der Miesmuscheln (Mytilus galloprovincialis Lamarck) gefunden worden sind. Die Miesmuscheln stammen aus zwei Gegenden des Golfes von Triest. Vier Hauptkomponenten erklären 76–78 % der totalen Varianz der beiden Stichproben. Die orthogonale-rotierte Faktorenmatrix zeigt, daß Co und Ni an die erste Hauptkomponente und Cd und Pb an die erste (Lage 2) oder an die zweite Hauptkomponente (Lage 1) gebunden sind. Die Herkunft der Spurenmetalle im Muschelfleisch aus dem Golf von Triest wird diskutiert.

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L. Felician is the author of the statistical analysis for site 1 as a part of his thesis in Commodity Science, Faculty of Economics, University of Trieste- L. Gabrielli Favretto is the author of the statistical analysis of the data for site 2. All authors contributed to the rest of the paper     

微波消解-电感耦合等离子体串联质谱法测定新疆黑枸杞红酒中微量元素的主成分分析

建立电感耦合等离子体串联质谱(inductively coupled plasma tandem mass spectrometry,ICP-MS/MS)分析方法测定新疆黑枸杞红酒中22种微量元素含量,并进行主成分分析.黑枸杞红酒经微波消解处理,采用ICP-MS/MS测定22种微量元素含量,在MS/MS模式下以O2为反...     

不同品种桑椹香气成分的主成分分析

采用顶空固相微萃取结合气相色谱-质谱联用（HS-SPME-GC-MS）技术测定来自国家种质镇江桑树圃中6种桑椹的香气成分,用主成分分析法对桑椹香气成分进行分析,并建立桑椹香气强度评价模型。结果表明:6种桑椹检测出48种香气成分,主要为醛类15种、醇类14种、酯类11种和酮类4种。经主成分分析,对前三个主成分进行可视化处理,6种桑椹根据香气成分差异归为6类,说明不同品种桑椹能够通过气质联用技术测定的香气成分进行区分;通过桑椹香气强度评价模型得出,桑椹香气强度综合得分由高到低依次为:镇椹1号、大十、镇9106、紫芽湖桑、淮场20号、镇8603,这与通过感官评价法得到的结果一致,表明所建立的桑椹香气强度评价模型是可靠的。      

A binary aqueous component model for the sediment-water partitioning of trace metals in natural waters

A model defining the overall sediment-water partitioning of a chemical, K(D), and the partitioning of its conservative components, (K(D))i, is presented. With respect to many trace metals in natural waters it is proposed that, through strong and perhaps specific complexation, two independent aqueous components coexist and a binary form of the model is appropriate. For two components of a metal that exhibit unequal partitioning, an inverse relationship between K(D) and particle concentration is predicted. Published experimental measurements of K(D) for metals in river waters, derived under conditions which exclude variable concentrations of preexistent colloidal particles, displayed either an inverse dependence (Cu, Ni, and Pd) or little dependence (Cs) on particle concentration. Regarding the former, iterative fits with the binary model were better than empirical fits based on a third (colloidal) phase model, and suggested the presence of between about 10 and 75% of a particle-reactive component ((K(D))1 approximately 5 x 10(4) to 10(10) mL g(-1)) and 25 and 90% of a less reactive (e.g., strongly complexed) component ((K(D))2 < or = 2.5 x 10(3) mL g(-1)). Regarding Cs, data indicated the presence of a single component whose K(D) was on the order of 10(3) mL g(-1). These observations challenge the conventional means by which sediment-water partitioning is considered and modeled, and imply that a third phase is not always a prerequisite for the particle concentration effect frequently observed in laboratory and field studies.     

FTIR-ATR spectroscopy as a tool for polysaccharide identification in edible brown and red seaweeds

Phycocolloids present in three brown (Himanthalia elongata, Bifurcaria bifurcata, Saccharina latissima) and five red edible seaweeds (Mastocarpus stellatus, Gigartina pistillata, Chondracanthus acicularis, Nemalion helminthoides and Dumontia contorta) were studied by FTIR-ATR spectroscopy. Infrared spectra of polysaccharide standards (alginate, agar, iota-, kappa- and lambda-carrageenan) were obtained for comparison. The main polysaccharide found in brown seaweeds was alginate, a linear copolymer of mannuronic (M) and guluronic acid (G). Alginate M/G ratio was tentatively estimated from specific absorption bands (808/787 cm⁻¹ and 1030/1080 cm⁻¹) in infrared spectra, suggesting higher values of mannuronic than guluronic acid blocks (M/G > 1) for brown seaweeds. According to their infrared spectra, all the red seaweeds studied were mainly carrageenan producers. Thus, M. stellatus showed absorption bands at 929.0, 844.7 and 803.2 cm⁻¹ of a typical hybrid kappa/iota/mu/nu-carrageenan, meanwhile G. pistillata and C. acicularis, showed the characteristic broad band (830–820 cm⁻¹) of lambda-type carrageenan. Moreover, when the second-derivative was obtained to improve resolution of overlapped bands in the original FTIR spectra, this band was divided into several sharper signals, indicating the presence of lambda-/theta-/xi-carrageenans. Accordingly with their FTIR spectra, N. helminthoides contained sulphated polysaccharides, such as carrageenan or mannans, while D. contorta produced lambda- with lesser amounts of kappa-carrageenan. Therefore, FTIR-ATR spectroscopy is proposed as a useful tool for the food, pharmaceutical and cosmetics industry to check the phycocolloid quality of a raw seaweed material by a quick and non-destructive method.     

Levels of eight trace elements in edible mushrooms from a rural area

Eight trace elements were determined using ICP-MS in 78 fruiting body samples of 22 edible mushroom species. The mushrooms were collected from four sites in a rural area, unpolluted by human activity. Median values (dry matter) were as follows: Arsenic (As) 1.45 mg kg^-1, barium (Ba) 1.41 mg kg^-1, cobalt (Co) 0.28 mg kg^-1, copper (Cu) 47.0 mg kg^-1, rubidium (Rb) 130 mg kg^-1, silver (Ag) 2.95 mg kg^-1, thallium (Tl) 0.02 mg kg^-1 and vanadium (V) 0.25 mg kg^-1. Higher trace element accumulation was observed in samples of Macrolepiota procera, Macrolepiota rhacodes, Lycoperdon perlatum, Lycoperdon gigantea and Xerocomus chrysenteron for As and Cu, and in samples of Cantharellus cibarius and of genera Boletus and Suillus for Rb.     

Levels of eight trace elements in edible mushrooms from a rural area

Eight trace elements were determined using ICP–MS in 78 fruiting body samples of 22 edible mushroom species. The mushrooms were collected from four sites in a rural area, unpolluted by human activity. Median values (dry matter) were as follows: Arsenic (As) 1.45?mg?kg^–1, barium (Ba) 1.41?mg?kg^–1, cobalt (Co) 0.28?mg?kg^–1, copper (Cu) 47.0?mg?kg^–1, rubidium (Rb) 130?mg?kg^–1, silver (Ag) 2.95?mg?kg^–1, thallium (Tl) 0.02?mg?kg^–1 and vanadium (V) 0.25?mg?kg^–1. Higher trace element accumulation was observed in samples of Macrolepiota procera, Macrolepiota rhacodes, Lycoperdon perlatum, Lycoperdon gigantea and Xerocomus chrysenteron for As and Cu, and in samples of Cantharellus cibarius and of genera Boletus and Suillus for Rb.     

Continuous subcritical water extraction as a useful tool for isolation of edible essential oils

A method for extraction of oregano oil based on the use of subcritical water is proposed. Ground oregano (ca. 1.8 g accurately weighed) was extracted with water at 2.0 MPa, 125 °C and 1 ml min⁻¹ for 24 min. The extracted compounds were removed from the aqueous extract by a single extraction with 4 ml hexane, determined by gas-chromatography-flame ionisation (GC-FID) and identified by mass spectrometry (MS). Hydrodistillation was performed on 30 g of ground oregano with 500 ml water for 3 h for comparison of the results with those provided by the proposed method. The subcritical water extraction-based method is clearly quicker and more efficient than the conventional: yields from the former for eight of the 11 major compounds in the extract are higher after 15-min extraction than after hydrodistillation for 3 h. This enables substantial cost savings of both energy and raw material. In addition, the proposed method has the possibility of manipulating the composition of the oil and thus its quality. The aqueous-oil extract was investigated for essential oil preparative purposes and several fast, cheap and clean alternatives for breaking the emulsion and separating the phases are proposed.     

Principal component analysis of the polyphenol content in young red wines

In the present study the content of 15 polyphenols was determined in 55 samples of red wines from different denominations of origin in the Canary Islands (Spain) using high performance liquid chromatography (HPLC) with UV and fluorescence detection. The most important differences in content among wines according to different categories (island, zone and denomination of origin) were established. In general, red wines from the Canary Islands had a content in polyphenols in the lower part of the range considered normal. The exception was quercetin, with a mean content (17.5 mg/l) higher than in other wines, which may be a peculiarity of these particular wines. The principal component analysis (PCA) technique was used to study the latent structure. A good differentiation among wines according to their production area was obtained using linear discriminant analysis (LDA).     

主成分分析法在研究宜宾芽菜风味物质变化中的应用

为研究宜宾芽菜发酵过程中风味物质变化情况,采用HS-GC-MS法对宜宾芽菜发酵过程中不同时期的样本分析,以该数据为样本,用主成分分析法研究其主要特征风味物质。结果表明:不同发酵时间段共检测出78种香味物质,其中有烯烃类21种、醇类23种、酯类12种、醛类4种、酮类7种、醚类3种、苯环类6种和其他类2种;利用主成分分析法共提取出6个主成分及对宜宾芽菜香味影响较大的物质12种。通过本文的研究能够掌握芽菜发酵过程中的风味变化,为芽菜的风味改善和新产品研发提供理论依据。      

新疆红枣无机元素地域分布相关性及主成分分析

为从无机元素指标获得红枣的品质和产地信息,按照电感耦合等离子体发射光谱仪（ICP-AES）方法测定新疆红枣资源的14个无机元素（K、Na、Fe、Mg、Zn、Mn、Ca、Cu、Al、As、B、Ba、Cd、Hg）的含量,应用相关性和主成分分析法对新疆主产区红枣品质进行分析。主成分分析得出一个4因子模型,并对该模型进行了详细的分析和解释;第1、2主成分的方差贡献率分别为36.077%和25.487%,对应的显著指标分别为Na、Fe、Mg、Ca、B和Cu、Al、Ba、Cd,显示出对红枣品质和产地评价非常重要;主成分分析同时将36个新疆红枣聚为5组,在一定程度上体现了新疆红枣样品的亲缘关系和地域分布特征。      

不同产地油茶籽脂肪酸及甘油三酯的主成分分析和聚类分析

开展了不同产地对油茶籽油脂肪酸和甘油三酯的影响研究。采用气相色谱法和高效液相色谱法,分别对我国47个产地的108份普通油茶籽样品的脂肪酸和甘油三酯组成及含量进行检测,并对其进行主成分分析和聚类分析。结果表明：从47个产地的108份油茶籽样品中共检测出10种脂肪酸,其中以油酸的含量最高,平均相对含量达79.86%,不同产地样品的脂肪酸中饱和脂肪酸含量差异显著（P＜0.05）,不饱和脂肪酸含量差异不显著（P＞0.05）,除海南省5个产地外,其余各个产地样品中油酸含量差异不显著;主成分分析结果显示,油酸、亚油酸、棕榈酸和硬脂酸是油茶籽油的特征脂肪酸;油茶籽中的甘油三酯包括12种组分,其中OOO含量最高,其次是POO和OOL,LLL和PPL含量最低;主成分分析结果显示,POO、SOO、SOP、PPO、POL+SLL、OOO是油茶籽油的特征甘油三酯成分;在主成分分析的基础上,以含量在1%以上的甘油三酯组分作为评价指标,对油茶籽油样品进行了聚类分析,将其划分为2类,第一类42个产地,第二类5个产地均属于海南省。该研究为我国普通油茶的鉴别分类和加工利用提供了理论依据和参考信息。     

Image analysis as a tool for measuring biological phenomena of the skin

In an industry very much concerned with image it is not surprising to find that Image Analysers are beginning to fulfil the potential that a few groups recognized some time ago. This presentation will outline briefly the principles of image analysis and demonstrate how these can be put to use in measurement. Skin will be referenced as the example almost throughout this text, though it is important to remember that there are other applications which may interest cosmetic chemists; in the field of particulates and emulsions for example, and generally in production quality control. Finally, since the technology is often very easy to use, potential dangers in its misuse will also be pointed out where necessary.     

六种市售禽蛋蛋清氨基酸主成分分析与综合评价

采用氨基酸比值系数法及主成分分析法对6种市售禽蛋蛋清的氨基酸水平和组成进行比较分析,以评价6种禽蛋的营养价值。结果表明,6种市售禽蛋蛋清均含有16种氨基酸且含量丰富,总氨基酸含量在8.977~11.926 mg/100g,其中方洪鲜鹌鹑蛋蛋清总氨基酸含量最高。画乡农聪明贝贝蛋、秦巴山土鸡蛋、秦巴山无公害鸡蛋和方洪鲜鹌鹑蛋蛋清必需氨基酸模式较为接近FAO/WHO必需氨基酸模式,必需氨基酸营养价值较高。主成分分析提取3个主成分并对6种市售禽蛋蛋清中氨基酸进行综合评价,结果表明鸟王五谷蛋综合质量最好,其次是方洪鲜鹌鹑蛋和秦巴山无公害鸡蛋。     

食用油中痕量镉含量的测定

将食用油灰化处理后,用APDC-DDTC-MIBK体系萃取富集试液中的镉,利用空气-乙炔火焰原子吸收法测定其含量.建立了优化的测定条件,并对可能存在的元素作了干扰实验.结果表明,测定镉的相对标准偏差为1.8%～3.1%,回收率为97.1%～101.5%,结果十分满意.