Effects of thermal treatments on the structure of two black coral species chitinous exoskeleton

Black corals (Antipatharians) are colonial cnidarians whose branched tree-like skeleton is constituted of chitin fibrils inside a lipoproteic matrix. The arrangement of the constituents of these materials provides a structure with outstanding physical properties. In this study, the structural properties of black coral skeletons of Antipathes caribbeana and Antipathes pennacea species are explored by means of thermal treatments in the range from room temperature up to 400 °C and the subsequent analysis using X-ray diffraction (XRD), infrared spectroscopy (FTIR), and thermal analysis (DSC/TGA). The effects of thermal treatment from room temperature up to around 210 °C induce the enhancement of the bands in the FTIR spectra and X-ray diffractograms, above that temperature, the FTIR and X-ray peaks become strongly attenuated. These effects are specially observed in the infrared bands associated to chitin at 3298 cm⁻¹ and to the secondary amide stretching around 1663 cm⁻¹, in particular, allowing the identification of the α-chitin in the black coral. XRD shows that the crystallinity index of the black coral chitin at room temperature is 24% and grows when the temperature increases, reaching a maximum value of 37% at 210 °C and decreases for higher temperatures. In addition, DSC and TGA measurements allowed identifying the most important transformation stages during the thermal treatments, namely, evaporation of water and the beginning and progress of degradation, depolymerization, and denaturation processes and finally, the degradation of the main functional groups of coral skeleton and coral chitin, in which the polysaccharide structure of chitin is depolymerized and the protein matrix is denatured.     

原子吸收光谱法测定武夷岩茶中金属元素的含量

本文采用原子吸收光谱法对武夷山岩茶中影响岩茶品质的铜、铁、锰、镁、钙、锌6种元素的含量进行测定。测定结果表明:武夷岩茶中含有丰富的人体必需的微量元素,其中钙、镁、锰、铁的含量与绿茶比较有明显的优势。     

Assessment of trace element levels in Rhododendron honeys of Black Sea Region, Turkey

Rhododendron and multi-flower honeys obtained from Black Sea Region of Turkey (12 Rhododendron and 8 multi-flower honeys) were studied to determine the presence of the 14 trace elements such as Cu, Cd, Pb, Co, Cr, Ni, Al, Se, Zn, Mn, Fe, K, Ca and Mg. Trace element determination was performed by atomic absorption spectrometry (AAS) after microwave digestion. The results revealed that Rhododendron honeys exhibited higher concentrations of Cu, Co, Cr, Ni, Se, Zn, Ca and Mg but lower concentrations of Al, Mn, Fe and K than in the multi-flower honeys. Trace element levels in analyzed honey samples were generally lower than literature values.     

藏药牦牛血粉饮片中氨基酸和无机元素测定

为建立藏药牦牛血粉饮片中氨基酸和无机元素的定性和定量分析方法,试验采用高效液相色谱-柱后衍生法对牦牛血粉中游离氨基酸进行测定:离子交换柱(2.5 mm×150 mm,6μm),检测波长为570 nm、440 nm,测试方法为单点矫正法;采用微波消解-ICP-MS对牦牛血粉中无机元素进行测定:测定模式为碰撞反应模式,碰撞气(He)流量5 mL/min。数据采集模式:跳峰扫描,采样深度8.0 mm,重复扫描3次。结果表明:牦牛血粉中含有一定量的游离氨基酸,其中包括8种人体必须氨基酸。无机元素以Al、Na、Mg、K、Ca、Fe为主,还含有V、Cr、Mn、Zn、Co、Ni、Cu、Se等人体所需微量元素,各无机元素均在浓度考察范围内,线性关系良好(r^2>0.9984),加样回收率在99.2%~108.4%之间。该研究初步明确藏药牦牛血粉饮片中氨基酸和无机元素的组成,方法准确高效,为综合评价藏药牦牛血粉饮片的质量提供科学依据和方法参考。     

Metallic species in atmospheric particulate matter in Las Palmas de Gran Canaria

In this work, we quantified the total, water-soluble and insoluble fractions of 12 metallic species (Na, Ca, K, Mg, Fe, Zn, Cr, Ni, Cu, Cd, Pb and Mn) present in total suspended particulates (TSP) in an urban area with heavy traffic (about 80 000 vehicles/day) of Las Palmas de Gran Canaria (Canary Islands). Experimental measurements were made from July to December 2003 on a total of 42 samples (7 per month). Particulate matter (TSP) was collected in fiber filters and high volume samplers. PM₁₀ levels were estimated assuming the PM₁₀ fraction is about 70% of all TSP. Total fractions was determined gravimetrically. Water-soluble fraction was extracted by sonication. Concentrations of metallic elements were analyzed by flame atomic absorption spectrophotometer. Temporal changes in the concentrations of the target elements were examined and a multivariate approach used to identify the primary sources for each species. Mean value for TSP is 71.92 μg/m³. The water-soluble fraction consisted mainly of Na, Ca, Mg, and K. The insoluble fraction contained higher concentrations of all elements than the soluble except Na. In the water-soluble fraction, Na, K, Ca and Mg were found to come mainly from natural sources; Cr, Pb, Cd, Ni, Zn and Cu from anthropogenic sources.     

Determination of the major,minor, and trace element mass fractions in Iranian cement by INAA and WDXRF

The elemental composition of three different Iranian cement samples was determined by instrumental neutron activation analysis with the aim of quality control. The mass fractions for 4 major (Ca, Si, Fe, Al) and the 21 minor and trace elements (Mg, V, Mn, Na, As, La, Sb, Sm, U, Ba, Ce, Co, Cr, Eu, Hf, Sc, Sr, Th, Zn, S, K) were determined. X-ray fluorescence analysis was also used. The results obtained by both methods for Na, Mg, Fe, Ca, and Al are in good agreement. On the whole, the Iranian cement quality is quite acceptable according to national and international standards.     

杭州市大气悬浮颗粒PM_(2.5)污染状况及化学组成特征分析

为了解杭州市大气悬浮颗粒物PM2.5污染状况及化学组成特征,2006年在杭州市内布设2个监测点位,按季节进行采样,并对悬浮颗粒物PM2.5中20种元素进行定量研究。结果表明:杭州市区大气中悬浮颗粒物PM2.5的年均质量浓度值为77.5μg/m3,其中S、Si、Ca、K等元素年平均质量浓度大于1.0μg/m3。元素Si、Al、Fe、Mg、V、K、Na、Ti、Mn、Ca、P、Cr、Ni主要来源于地壳,而元素Cl、Cu、Zn、Pb、As、Br、S、Se等主要来源于人为排放源。     

Attack of cement pastes exposed to organic acids in manure

Manure such as silage effluents and liquid manure contains organic acids which constitute a severe chemical threat toward the concrete of agricultural structures. The purposes of this study were to identify the chemical composition parameters that influence durability by analysing the behaviour of the chemical elements of the cement paste (Ca, Si, Al, Fe and Mg) in organic acid solutions and to compare the intensity of the chemical attack by the different acids found in liquid manure. This study was carried out on cement pastes made from four binders (ordinary Portland cement, slag cement, OPC blended with silica fume and OPC blended with fly ash). The hardened cement pastes were first crushed, then immersed in solutions made of five organic acids with an initial pH of 4 and constantly stirred. The pH and the concentrations of major elements were monitored over time.

The results show that Si, Al, and Fe appear to be favourable elements for the chemical resistance of binders whereas the amount of Ca should be limited. Moreover, it is shown that the four acids found in liquid manure (acetic, propionic, butyric, iso-butyric) are equally aggressive. Lactic acid, present with acetic acid in silage effluent, is more aggressive according to the value of its pK_a.     

海芒果树叶中氨基酸和微量元素的分析

采用高效液相色谱法和等离子发射光谱法,分析测定了红树植物海芒果Cerberamanghas树叶中氨基酸和微量元素成分。结果表明,叶子提取液中含有16种氨基酸,其中6种为必需氨基酸,2种为半必需氨基酸,其中必需氨基酸占总氨基酸的33.20%;15种微量元素,分别为Al、As、Ba、Ca、Cd、Cr、Cu、Fe、Mg、Mn、Ni、Pb、Sr、Ti、Zn。     

微波消解-ICP-AES／ICP—MS测定大米中微量元素

采用微波消解技术,电感耦合等离子体光谱（ICP-AES）和电感耦合等离子体质谱（ICP—MS）测定了分别产自辽宁、四川、湖南三地的大米中21种元素B、Ba、Ca、Cd、Cu、Fe、K、Mg、Mn、Na、P、S、Sr、Zn、Co、Ni、Cr、Mo、Pb、Li、Cs。所有元素标准曲线回归方程线形系数均大于0．999,各元素相对标准偏差（RSD）均小于5．31％（测定次数n=4）,加标回收率为96．6％-110．6％,方法检出限：ICP-AES为0．0048-0．33μg·mL-1,ICP-MS为0．022-0．192ng·mL-1。用国家一级标准物质大米（GBW10010）验证了方法的准确性,测定值与推荐值相符,实验表明,P、S、K、Mg、Ca、Na、Zn、Mn、Fe、Cu在大米中含量较高。此方法简便、快速,适用于大米等粮食作物中微量元素的测定。     

Study of ambient air particulates pollutants near Taichung airport sampling site in central Taiwan

This study monitored the atmospheric pollutants at Taichung airport (TA) sampling site during September to December of 2005 near Taiwan Strait in central Taiwan. The distributions of the particle concentrations between the TSP, coarse and fine were also displayed at TA sampling site. Analysis the average percentage of various kinds of metallic elements, the data obtained here indicated that the average percentage concentrations of metallic elements Fe and Mg were higher in fine particulate than that of the coarse particulate at Taichung airport sampling site. These foundry factories were by the TA sampling site was the possible reason responsible for this result. In addition, by a non-parametric (Spearman) correlation analysis, the results indicated that Fe, Mn and Pb have high correlation coefficients of metallic elements in different particle size. The results indicate that the airport pollutants might come from similar pollutant sources at this airport sampling site. In addition, high correlation coefficients of non-airport pollutants were observed on the ionic species of SO(4)(2-), NH(4)(+) and K(+). The r(sp) correlate values between closed to r(sp)=0.7 and 0.9 at different particles size mode. Besides, the ionic Ca(2+) has high negative values (r(sp)=-0.66, -0.66 and 0.61) with the increasing of the temperature, relative humidity and wind speed, respectively at fine particle size.     

Separation of hafnium and zirconium from ti- and fe-rich geological materials by extraction chromatography

This paper presents a new chemical separation method for Hf and Zr from rocks using extraction chromatographic resins prepared from inert polymeric supports and the liquid anionic exchangers tri-n-octylamine or trioctylmethylammonium chloride (Aliquat 336). The method was developed using basaltic and trachyandesitic rocks with high contents of Al, Fe, and Ti. A 100-mg rock sample was decomposed with HF-HNO(3)-HClO(4) and fumed with HClO(4). The residue of this process was dissolved in 10 M HCl and then loaded on the column (6 mm i.d. × 75 mm). The major elements (Al, Ca, Mg, Ti, etc.) were eluted with 10 mL of 10 M HCl, and then Hf, Zr, and Fe were eluted sequentially using 20 mL of 8 M HCl, 20 mL of 2 M HCl, and 5 mL of 1 M HNO(3). The removal efficiency of major elements (Al, Fe, Ca, Mg) was greater than 99% and that of Ti was greater than 95%. The recoveries of Hf and Zr were better than 90% and the Zr/Hf ratio decreased from the natural ratio of 45 in the rock sample to 0.3 in the Hf fraction. This method provides an alternative to the less straightforward procedures based on several stages of ion-exchange separation and might be used for sample preparation prior to (176)Hf/(177)Hf determinations by magnetic sector multicollection ICPMS.     

大杯伞子实体常见微量元素的定性定量测定

利用扫描电镜和X射线能谱仪对大杯伞子实体的菌盖、菌褶和菌柄中的常见微量元素Na、Mg、Ca、K、Fe、Cu、Mn和Zn进行测定,并计算出它们的相对重量百分比。结果表明菌盖、菌褶和菌柄均含上述各种微量元素,但含量并不相同。     

Optical,thermal, and structural characterization of the sclerotized skeleton of two antipatharian coral species

Optical, thermal and structural characterization of the skeleton of two black coral species from the Western Caribbean Sea, Antipathes caribbeana and Antipathes pennacea is presented. Optical spectra in the UV–VIS region of both species have a strong absorbance around 350 nm. FTIR spectra in the mid-infrared spectra show the presence of a complex material similar to chitin for both species. X-ray diffraction analyses demanded a deproteinization treatment in order to observe the significant differences in the crystalline structure of chitin. The crystallite size in A. caribbeana is larger than in A. pennacea. Thermal characterization, performed by the photoacoustic technique, shows that in A. caribbeana skeleton the thermal conductivity is higher as compared with the thermal conductivity of the skeleton of A. pennacea. The difference in the thermal properties between coral species could be due to the array and packing of the chitin fiber skeletons.     

不同因素对钼及钼合金塑脆性能影响的研究

钼及其合金具有很好的高温强度和抗腐蚀性等优异性能,广泛应用于众多高科技领域.综述了C、N、O杂质元素、掺杂元素和稀土氧化物、常规的K、Si、Al、Ca、Mg、Fe等元素以及织构等因素对钼及钼合金塑脆性能的影响,总结了提高钼合金塑性的基本方法和规律.同时指出钼及钼合金今后研究的重点是提高合金的横向塑性,以使其得到更广泛的应用.     

ICP-AES法测定水中14种元素的研究

本文对使用ICP-AES法测定水中含有的钠、钾、钙、镁、铝、钡、铜、钴、铁、锰、钼、铬、镍、硅等元素进行了研究,该方法可获得良好的灵敏度,对多元素含量的测量速度快,回收率为96%-103.4%,标准曲线相关系数大于0.9998,相对标准偏差小于5.0%,测定检测限低,能够满足分析的需要。     

A multivariate study: variation in uptake of trace and toxic elements by various varieties of Sorghum bicolor L

The aim of present study was to evaluate the variation in uptake of elements (As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn) by different varieties of Sorghum bicolor L., plants grown in soil amended with untreated industrial waste water sewage sludge (SUIS), on same experimental plots. The power of chemometrics was also used in exploring the potential natural and/or anthropogenic sources responsible for elemental contents in different varieties of sorghum. Hierarchical cluster analysis was used to explore the different variety of sorghum grouping according to corresponding their SUIS samples as additional information to the output obtained by principal component analysis. Significant genotypic variation was detected in the fourteen elements concentrations in sorghum grains, indicating the possibility to reduce the concentration of toxic elements in grains through breeding approach. It was observed that high tolerance limit of toxic elements was observed in sorghum variety PARC-SV-1.     

沙尘期间大气颗粒PM_(10)与PM_(2.5)化学组分的浓度变化及来源研究

于2006年3月—4月北京沙尘发生期间,监测了沙尘与非沙尘期间悬浮颗粒PM10和PM2.5质量浓度,分析了样品中无机水溶性离子和金属元素。结果显示:沙尘天气导致PM10和PM2.5质量浓度上升,粗颗粒物质量浓度明显上升,细颗粒物受到的影响相对较小。SO42-、NO3-和NH4+为PM10与PM2.5主要水溶性离子。沙尘与非沙尘期间SO42-、NO3-和NH4+浓度变化表现出不稳定性,可能与沙尘的强度和持续时间、来源有关,沙尘下来自于土壤源Ca2+和Mg2+浓度都显然提高。沙尘期间Sc、Ti、V、Cr、Mn、Co、Ni、Rb和Cs金属元素浓度高于非沙尘期间浓度,并且富集因子系数都小于10,说明主要来自于自然源,而Zn、Se、Cd、Pb和Bi这5种元素浓度随沙尘的侵入并没增加其含量,反而使浓度有所下降,富集因子和富集程度对比表明这些元素主要来自于当地污染源。     

In Vivo Study on Degradation Behavior and Histologic Response of Pure Magnesium in Muscles

When an orthopedics device is implanted into bone injury site, it will contact the soft tissue(skeletal muscle, fascia, ligament etc.) except for bone. Magnesium based biodegradable metals are becoming an important research object in orthopedics due to their bioactivity to promote bone healing. In this study,pure Mg rods with and without chemical conversion coating were implanted into the muscle tissue of rabbits. Implants and their surrounding tissues were taken out for weight loss measurement, crosssectional scanning electron microscopy observation, elemental distribution analysis and histological examination. The results showed that the chemical conversion coating would increase the in vivo corrosion resistance of pure Mg and decrease the accumulation of calcium(Ca) and phosphorus(P) elements around the implants. For the bare magnesium implant, both Ca and P contents in the surrounding tissues increased at the initial stage of implantation and then decreased at 12 weeks implantation, while for the magnesium with chemical conversion coating, Ca and P contents in the surrounding tissues decreased with the implantation time, but were not significant. The histological results demonstrated that there was no calcification in the muscle tissue with implantation of magnesium for up to 12 weeks. The chemical conversion coating not only increased the in vivo corrosion resistance of pure Mg, but also avoided the depositions of Ca and P in the surrounding tissues, meaning that pure magnesium should be biosafe when contacting with muscle tissues.     

扫描电镜和X射线能谱仪对真姬菇子实体常见微量元素的定性定量测定

利用扫描电镜和X射线能谱仪对真姬菇子实体菌盖、菌褶和菌柄中的常见的微量元素Na、Mg、S、P、K、Ca、Mn、Fe、Cu和Zn进行测定,并计算了它们的相对重量百分比。结果表明真姬菇子实体的菌盖、菌褶和菌柄的微量元素含量各不相同。