大蒜微量元素的分析与研究

用火焰原子吸收光谱法和原子荧光法分析研究了大蒜中12种微量元素Fe、Cu、Zn、Mn、Ni、Pb、Cd、Cr、As、Sb、Se和Hg的含量,结果表明产于湖南隆回县山界回族乡的大蒜中含有丰富的微量元素Fe、Cu、Zn、Mn和Se,对人体健康非常有益。样品测定结果表明:大蒜中上述微量元素标准曲线的相关系数在0.9995~0.9999之间,呈现良好的线性关系;相对偏差(RSD)在0.06%~4.33%之间;各元素的加标回收率在94.5%~107.0%之间。     

ICP-MS测定银杏叶茶中的多种微量元素的研究

采用微波消解银杏叶茶样品,电感耦合等离子体质谱法(ICP-MS)同时测定试样中As、Cr、Cu、Co、Pb、Hg、Bi、Ba、Be、Li、Ni、Sr、Ti、V、Zn、Mn、Mo、Sb、Se微量元素含量,同时对方法学进行考察。结果表明,此方法测定的各元素的相对标准偏差在1.22%~9.75%之间,加标回收率在91.9%~103.9%之间,此方法具有较高的精密度和加标回收率,适用于生物样品中多种金属元素的测定。ICP-MS法为银杏叶的开发和利用提供了科学依据。     

微波消化-ICP-OES法测定纺织品中多种重金属元素

研究了纺织品中重金属元素As、Bi、Cd、Co、Cr、Cu、Fe、Mn、Mo、Ni、Pb、Zn的测定方法,采用微波消解处理样品,ICP-OES法测定纺织品中的多种重金属元素,选取了最佳仪器分析条件,加标回收率为96.4%~104.1%,相对标准偏差小于5.0%,与其他方法相比,具有快速、简便、灵敏、污染少等特点。     

微波消解ICP-AES法测定微山湖野生莲子中的微量元素

通过采用HNO3作为消解剂对样品进行微波溶样,电感耦合等离子体原子发射光谱法(ICP-AES)对微山湖野生莲子中Li、Mg、Mn、Ni、Zn、Cd、Pb、Se、Co、Cr、Cu和Fe等多种元素进行测定,各分析元素的加标回收率在93.6%～104.%之间,RSD≤2.53%,结果令人满意。     

ICP-AES法同时测定卤鸭肉制品中的9种微量元素

采用湿法消解卤鸭肉样品,ICP-AES测定Cd、Cr、Cu、Fe、Mn、Ni、Pb、Zn 8种元素,对于痕量As,使用HG-ICP-AES测定。优化了ICP-AES的工作条件,探究了氢化物发生最佳条件。As的检出限为0.00027 mg/L。回收率范围为92.5%~108.0%,大部分元素的RSD在5%之内。     

ICP-MS法同时测定地表水中21种痕量元素

以6 Li、Sc、Ge、Y、In、Bi 6种元素作内标校正系统,采用电感耦合等离子体质谱法(ICP-MS)同时测定地表水中的Be、Mg、Ca、V、Cr、Mn、Co、Ni、Cu、Zn、As、Se、Mo、Ag、Cd、Sb、Bs、Tl、Pb、Th、U 21种痕量元素,结果表明:各元素的线性系数均>0.999 5,方法检出限为0.006～0.738μg/L,标准样品的测定值均在标准范围内且RSD<4.22%,样品中各元素的加标回收率为95.0%～116.1%。     

FAAS法测定凌云白毫茶中8种微量元素

采用硝酸-高氯酸(4∶1)消解样品,火焰原子吸收法测定广西凌云白毫茶茶叶中8种微量元素Fe、Mn、Cu、Zn、Ni、Pb、Cr和Cd的含量,结果表明凌云白毫茶中含有丰富的微量元素Fe、Mn、Cu和Zn,对人体健康非常有益。8种元素含量为FeZnMnCuNiCdCr,不含Pd,各元素的回收率在95.5%~106.0%之间,该方法灵敏度高,操作简单、快速,结果准确,是白毫茶微量元素测定的理想方法。     

电感耦合等离子体发射光谱(ICP-OES)同时测定煤基活性炭中铅、锌、锑、镍、硒、镉、铬、锰、镧、砷、铝、铁12种元素

使用ICP-OES同时测定活性炭中Pb、Zn、Sb、Ni、Se、Cd、Cr、Mn、La、As、Al和Fe等12种金属元素。采用高氯酸和硝酸处理样品,以硝酸作为测定介质,在选定的仪器工作条件下直接进行测定。各元素的测定检出限为0.002~0.068μg/m L,相对偏差(RSD,n=6)为0.19%~2.28%。对样品进行加标回收试验,回收率在95.36%~109.44%之间。结果表明,使用ICP-OES法测定活性炭中金属元素具有较好的精密度和准确度,可以满足活性炭和以活性炭为载体的催化剂杂质元素分析的要求。     

密闭微波消解ICP-MS同时测定电解锰阳极液中12种元素

利用HNO_3-H_2O_2密闭微波消解-ICP-MS同时测定电解金属锰阳极液中12种元素(Fe、Pb、Ni、Zn、Sr、Cr、Ti、Co、Cu、Cd、Sb、Ge),内标铟(In)和铋(Bi)消除基体效应和仪器信号漂移。结果表明,该方法具有较强的抗干扰性(相关系数r0.9999),加标回收率均为93.93%~106.16%,相对标准偏差RSD3.5%。该方法操作简单、快速,适用于电解金属锰阳极液中多种元素的同时检测。     

ICP-OES法测定矮地茶中微量元素含量

为测定矮地茶中微量元素,采用湿法硝酸-高氯酸进行消解,用ICP-OES法测定了矮地茶中Cu、Pb、Zn、Mn、Cd、Ni、Fe、Ca、As等9种元素含量。结果表明:方法操作简单、快速、灵敏,分析结果的相对标准偏差为0.49%~4.34%,方法的加标回收率为95.0%~102.1%。矮地茶中含有丰富的对人体有益的Ca、Fe、Zn、Mn、Cu等元素,有害元素Pb在根茎和叶中的含量差异较大,根茎中Pb已超过限量标准。结果可为矮地茶的开发利用提供依据。     

Volatility and chemistry of trace elements in a coal combustor

The volatility of 16 trace elements (TEs) (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se, Sn, Te, Tl, V, Zn) during coal combustion has been studied depending on the combustion conditions (reducing or oxidizing) and type of coal (high- or low-ash coal), together with their affinities for several active gaseous atoms: Cl, F, H, O, and S.

The elements can be divided into three groups according to their tendencies to appear either in the flue gases or in the fly ashes from a coal combustor:

Group 1: Hg and Tl, which are volatile and emitted almost totally in the vapor phase.

Group 2: As, Cd, Cu, Pb and Zn, which are vaporized at intermediate temperature and are emitted mostly in fly ashes.

Group 3: Co, Cr, Mn and V, which are hardly vaporized and so are equally distributed between bottom ashes and fly ashes. In addition, Sb, Sn, Se and Te may be located between Groups 1 and 2, and Ni between 2 and 3.

At 400 and 1200 K, the 16 TEs behave differently in competitive reactions with Cl, F, H, O and S in a coal combustor.     

ICP-OES测定玩具新指令第三类物质17种可迁移元素

本实验通过试验,对ICP-OES仪器工作条件进行了选择和优化,建立了ICP-OES测定欧盟玩具安全新指令限制第三类物质的17种可迁移元素（铝、锑、砷、钡、硼、镉、铬、钴、铜、铅、锰、汞、镍、硒、锶、锡、锌）的方法。本方法的检出限低,选取的第三类物质：涂层、聚合物、纸张、纺织品、金属、木材等多种材料的平均回收率均在94%~109%。结果显示方法有良好的准确度。     

Affinage electrolytique des ferronickels

Electrorefining of ferronickels is possible in a cell without diaphragm with the electrolyte CaCl₂ 5 M at 98°C.Behavior of the following impurities have been studied: Ag(I), Au(III), Bi(III), Cd(II), Co((II), Cu(I), Fe(II), Hg(II), Ni(II), Pb(II), Pd(II), Sb(III) and Sn(II).The electrochemical system Ni(II)/Ni(O)is much more reversible in this electrolyte and the only other electrochemical system which appears at the same potential is Cu(I)/Cu(O).Ferronickels of 23.2;72.2 and 94.4% in nickel have been refined in this medium without purification of the electrolyte. Nickel of a purity between 98.7 and 99.7% is obtained.In order to increase the nickel purity and for continuous operation of the method a purification of the electrolyte is necessary. Two methods are proposed: anion exchange resin and liquid—liquid extraction with tri-n-butyl phosphate (TBP).Partition coefficients and ion-exchanger capacities are given for following impurities: Fe(III), Fe(II), Co(II), Cu(II), Mn(II), Zn(II), Cr(III) and Pb(II).Percent extracted by TBP for following impurities are given: Fe(III), Fe(II), Co(II), Cu(II), Zn(II), Mn(II), Cr(III), Pb(II), Al(III), Bi(III), Sb(III) and Sn(IV).A continuous purification of the electrolyte by ion-exchange has been done in the refining of a ferronickel 94.4% in nickel. Nickel obtained is 99.74%.CaCl₂ 5 M appears to be a good electrolyte for electro-refining of nickel.     

The variation of element contents in triticale during vegetative growth

The variation of N, P, K, Ca, Mg, Fe, Mn, Zn, Cu, B, Ba, Be, Bi, Sn, Sr, Sb, Ti, Te, V, Se, As and Hg concentrations was studied under field conditions in triticale. The samples were collected every 10 days from tillering to full ripening stage using plant material from 0.5 m² per plot. The concentrations generally decreased from early growth to harvest. The elemental concentrations in triticale differed from the other cereals, but the variation's trend was similar.

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Zusammenfassung Es wurden die Schwankungen in den Konzentration von N, P, K, Ca, Mg, Fe, Mn, Zn, Cu, B, Ba, Be, Bi, Sn, Sr, Sb, Ti, Te, V, Se, As und Hg in Triticale unter Feldbedingungen untersucht. Von der Bestockung bis zur Vollreife wurden alle 10 Tage von je 0.5 m² pro Parzelle Pflanzenproben genommen.In allgemeinen haben die Konzentrationen von Frühjar bis zur Ernte abgenommen.Der elementengehalt in Triticale war demjenigen der übrigen Getreidearten verschieden, aber der Trend der Änderungen war ähnlich.

     

REACTION BETWEEN METALS AND MOLTEN GLASS *

A series of melts of soda-lime-silica glass cullet in contact with various chemical elements was made to determine by observation the extent of the reaction between metal and glass. The heat treatment consisted of a period of two hours at about 1250°C. An atmosphere of hydrogen gas was used to protect the element from oxidation during the the test period. Various colors were produced by Cu, Ag, Au, Se, C, S, and Zr. Black fogs resulted from melts containing Ba, Cr, or V; gray or black fogs with reddish zones resulted from Mg, Ca, Ti, Mn, Si, and Al. A faint blue with large reddish zones was produced by Co. Only slight attack was shown by Fe, Ni, Zn, Cd, Bi, Sn, Pb, Mo, and W.     

Volatilisation of trace elements for coal–sewage sludge blends during their combustion☆

The influence of sewage sludge addition on the volatility of 37 trace elements (Ag, As, Au, B, Ba, Bi, Cd, Ce, Co, Cr, Cs, Cu, Ga, Hf, Hg, La, Li, Mn, Mo, Nb, Ni, Pb, Rb, Sb, Sc, Se, Sn, Sr, Ta, Te, Th, Tl, U, V, Y, Zn, Zr) during coal combustion was studied. For this purpose, a bituminous coal from the Asturian Central Basin and sewage sludge treated with Ca(OH)₂ and FeCl₃, as well as 10 and 50 wt% sludge–coal blends were used. Combustion experiments were performed in a laboratory electric furnace at 800, 900, 1000 and 1100 °C. The results have confirmed that the high Cl contents of the sludge can produce a pronounced effect on the volatilisation of some trace elements (Ag, Cd, Cs, Cu, Li, Pb, Rb and Tl) due to the probable formation of volatile chlorides, while the high CaO concentrations increase the retention of some elements in ash as As, Se and Te. The above opposite effects of Cl and CaO on trace element volatilisation were generally inappreciable for the 10 wt% blend, while they were more significant, but not as noticeable as expected, for the 50 wt% blend.     

应用ICP-MS同时测定矿泉水中22种微量金属

研究结果表明应用ICP-MS可以同时测定饮用天然矿泉水中的Li、Be、B、Al、Ti、V、Cr、Mn、Co、Ni、Cu、Zn、Ge、As、Se、Sr、Mo、Ag、Cd、Sb、Ba、Pb、等微量金属元素.ICP-MS法具有快速、准确、处理简单、干扰少等优点.     

Electrodeposition of lead alloys from fluoborate baths

The codeposition of some elements with lead from fluoborate baths has been studied in order to obtain lead alloys with a low concentration of a second metal. The metals considered were As, Bi, Cu, Sb, Se, Sn and Te. The chemical analysis of alloys obtained in various electrolysis conditions permitted an investigation of the kinetic behaviour of the metals codeposited with lead. The results showed that only Bi, Sb, Se and Te attain a limiting value of discharge current density and that the codeposition is regular for all metals. SEM observation of the deposits revealed that Sb and Se have a marked influence on the crystal morphology while the remaining metals induce only minor modifications.     

Catalytic influence of metal melts on the graphitization of monolithic glasslike carbon

A study was made of the graphitization of monolithic glasslike carbon as catalyzed by molten metals. The heat treatment temperatures were 100 to 200°C higher than the melting points of the metals used and the hold time was 5 min in all cases. The results are compared with those of previous investigations on compacts prepared from metal and carbon powders. It is concluded that elements such as Ni, Co, Fe, Pt, Mo, Cr, and B are highly effective in catalyzing the graphitization. In the case of Mo, Cr, and B, the reaction may take place via an intermediate formation of the carbide. The mechanism of isothermal solution and spontaneous reprecipitation as proposed by Fitzer and Kegel applies to these metal catalysts. Metals such as Ag, Mg, Zn, Cd, Ge, Sn, Pb, Sb, Bi, Se, Te, and Pd show no such reaction. The previous literature revealed that Cu and Al were effective in contact with powderized carbon. But in the present work the insolubility of carbon in these metals and their failure to wet carbon, prevent penetration and subsequent graphitization of monolithic glasslike carbon. Interaction of Si, Zr, and Nb with carbon leads to high melting carbides or solid solutions which are solids at the temperature of the experiment. The resulting thin intermediate layers prevent penetration of the metal melt into monolithic glasslike carbon.     

Catalytic graphitization of carbons by various metals

A study was made of the catalytic graphitization of carbons by 22 kinds of metals. Heat treatments were carried out at 2600°C for 1 hr and 3000°C for 10 min under argon atmosphere. In graphitizing 3,5-dimethylphenol-formaldehyde resin carbon powder with which 20w/o metal powder (Al, Cr, Mn, Fe, Co, Ni, Ca, Ti, V, Mo and W) was mixed, graphitic carbon was catalytically formed. The first six metals, which belong to the carbon dissolution-precipitation mechanism, gave large graphitic crystal flakes at an early stage of the reaction; the other metals resulted in fine crystals through the carbide formation-decomposition mechanism. For the non-graphitizing phenol formaldehyde resin carbon in which 10w/o metal powder was dispersed, Mg, Si, Ca, Cu and Ge catalyzed formation of only graphitic carbon; and Al, Ti, V, Cr, Mn, Fe, Co, Ni, Mo and W formed both graphitic and turbostratic carbons. Except for Al and Cu, the former effect was exerted by non-transition metals and the latter effect by transition metals. Boron alone markedly accelerated homogeneous graphitization of both kinds of carbon; and Zn, Sn, Sb, Pb and Bi had no catalytic effect. On the basis of these results, the relationships between some properties of the metals, their catalytic abilities and the kind of catalytic effects are discussed.