用1，10-二氮杂菲分光光度法测定沉淀法白炭黑中的铁含量

提出并研究了使用１，１０－二氮杂菲分光光度法测定沉淀法白炭黑中铁含量的分析方法。其具体步骤为：首先用氢氟酸处理试样，使沉淀法白炭黑（二氧化硅）转化成四氟化硅气体逸出。而后在ＰＨ为４－５条件下，有盐酸羟胺处理剂将残留液中的三价铁离子还原成二价离子，加入１，１０－二氮杂菲显色剂（与二价铁离子反应可生成橙红色络合物），再用分光光度法测定其中的铁含量。实验表明：本方法原理可靠，分析步骤简便，抗铜，锰离子干     

火焰原子吸收光谱法测定白炭黑总铁含量

采用硫酸沉淀法生产白炭黑（沉淀水合二氧化硅），管道容器的腐蚀程度只有从白炭黑成品总铁含量中发现。由此可见，总铁含量测定在白炭黑生产中是不可缺少的。采用经典的邻菲啰啉分光光度法测定铁含量，操作较为繁琐，耗时长，干扰较多，不能满足快速分析的要求。     

光谱一电化学法测定硫酸中的铁和铅

在０．１ｍｏｌ／ＬＨＡｃ—ＮａＡｃ（ｐＨ４．０）的支持电解质中，使用０．１ｇ／Ｌ邻菲啉（ｏ－ｐｈｅｎ），采用经典分光光度法测定铁离子；同时，以络合物吸附波极谱法测定铅离子．检测下限可达１．５×１０￣（１０）ｍｏｌ／Ｌ。该方法的回收率为９９．２％～１００．４％，选择性好。     

高纯钛氧化物中微量铁的萃取分光光度测定

利用二氯乙烷萃取邻二氮菲－铁（Ⅱ）－苦味酸盐三元配合物,可以藉分光光度法测定钛氧化物中的微量铁,表观摩尔吸光系数为１．２２×１０＾５。方法灵敏,干扰少,已用于高纯钛氧化物中微量铁的测定。     

光度法测定头孢氨苄

以Ｆｅ（３＋）－邻二氮菲混和液作为显色剂，用光度法测定头孢氨苄的含量。测定波长为５１０ｎｍ。在１～１０μｇ／ｍｌ范围内回归方程为Ａ＝０．０１８＋０．０６２ｃ，γ＝０．９９９１。回收率的结果较为满意，方法简便、快速。     

耐火材料中二价铁和三价铁含量的测定方法研究

研究了在氮气保护下用氢氟酸-硫酸在不透光的容器中加热分解试样,采用邻二氮杂菲分光光度法测定耐火材料中的二价铁和三价铁。结果表明:样品分解的最佳条件是遮光、煮沸,待测溶液的有效期为24 h,显色剂邻二氮杂菲(5 g·L-1)的合适用量为5 m L,显色反应的pH以3. 5为宜。测定标准物质结果的相对标准偏差为0. 40%～3. 8%。试验内容和结论成为GB/T 34176—2017《邻二氮杂菲分光光度法测定耐火材料中的二价和三价铁离子化学分析方法》的制定依据。     

猕猴桃中铁含量的测定与测定因素的探究

在弱酸溶液中,抗坏血酸将铁离子还原为亚铁离子,亚铁离子与邻二氮菲形成橙红色络合物。利用铁对可见光的特性吸收,用分光光度法测定了510 nm处的吸光度,计算出汶川县三江镇的猕猴桃中铁的含量。铁标准曲线方程为Y=78.159X,线性相关系数R=0.9999。猕猴桃中铁的含量为0.1383 mg/g。     

分光光度法测定硅溶胶中微量铁离子

研究了用邻二氮菲作显色剂、以分光光度法测定硅溶胶中微量铁离子含量的方法。该法将硅溶胶样品在pH=1.0～1.5的盐酸溶液中进行预处理,最佳浸泡时间为3h。研究表明,经过预处理后的硅溶胶中铁离子含量的分光光度法测定结果与原子吸收光谱法的测定结果基本吻合。该方法具有成本低、方便快捷、重现性好等特点,可作为常规测试手段。     

高纯钛氧化物中微量铁的萃取分光光度测定

利用二氯乙烷萃取邻二氮菲－铁（Ⅱ）－苦味酸盐三元配合物,可以藉分光光度法测定钛氧化物中的微量铁,表观摩尔吸光系数达１．２２×１０５。方法灵敏、干扰少,已用于高纯钛氧化物中微量铁的测定。     

蒸汽冷凝液中微量PO4^3—的测定

探索了用氯化亚锡还原光度法代替原用分光光度法测定锅沪蒸汽冷凝液中的微量ＰＯ４３－。实验最大吸收λ＝７００ｎｍ，表观摩尔吸收系数ε＝１．８×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，ＰＯ４３－含量在２．５×１０－５～６．０×１０－４ｍｇ／ｍｌ内服从比尔定律，测定回收率为９３％～１０６％，标准偏差３．９（ｎ＝７）。已应用于实际生产中，结果满意     

铁矿粉中微量硅含量测定方法研究

报道了一种精铁矿粉中微量二氧化硅含量测定的新方法,重点探讨了操作中各步骤的最佳工艺及其对硅含量分析精确度的影响。本方法分析精确度高,适合于精铁矿粉中微量二氧化硅含量(SiO2:0.01%～1%)的测定,比传统方法测定极限下延了10倍。     

STAINING OF GLASS CONTAINERS IN CONTACT WITH IRON*

A wet glass surface brought in contact with metallic iron acquires a brown stain which cannot be removed easily. This phenomenon was observed by the industry interested in the automatic washing of glass containers. Iron in contact with wet glass surfaces will produce a chemically detectable contamination in one minute and a visible stain in ten minutes. This reaction of the glass surface with iron is galvanic in nature. Iron immersed in water sends positively charged ferrous ions into solution and leaves the metal with a negative charge. In the neighborhood of the iron, a negative electrical potential is established in the glass surface which helps to attract the positively charged ions from the solution. The stain is a result of the interaction of the glass surface and the iron ions, thus leading through oxidation to the formation of an insoluble, colored ferric hydrosilicate. The staining can be prevented by reagents which (1) prohibit the corrosion of the iron, (2) block the active centers of the silica gel, and (3) produce anionic iron complexes.     

Quantitative Si MAS NMR spectroscopy of cement and silica fume containing paramagnetic impurities

The low natural abundance and the long spin lattice relaxation time of ²⁹Si lead to long measurement times and/or low signal-to-noise ratios using ²⁹Si magic angle spinning NMR spectroscopy. By contrast, samples containing paramagnetic iron ions have much shorter relaxation times, making measurements up to seven times more efficient, but at the same time making quantitative analysis unreliable. To solve the problem, the spin-lattice relaxation times of ordinary Portland cement (opc) and silica fume with and without iron content has been determined with inversion recovery experiments. The effect of varying the spectrum repetition time on the quantitative analysis is demonstrated for mixtures of opc with silica fume. For opc and silica fume with iron impurities repetition times as short as 5 s has permitted accurate quantitative analysis of the silicates present in these materials.     

A new spectrophotometric method for the determination of ferrous iron in the presence of ferric iron

A new spectrophotometric method for the determination of ferrous iron concentration in samples containing ferric iron is presented. This new method is a modification of the Muir o-phenanthroline ferrous iron determination method. The new method consists of the quantitative spectrophotometric determination of Fe(II) by o-phenanthroline, but in which the ferric iron is complexed with sodium fluoride to eliminate interferences. A critical experimental comparison between the Muir spectrophotometric method, the Kolthoff titrametric method and the new proposed method is presented. Whenever Fe(III) accounts for more than 50% of the total iron in a sample, the method of Muir overestimates Fe(II). The proposed method has a range of 1–10 μg ferrous iron. It is as insensitive to other metal ions as the original method of Muir and is insensitive to Fe(III) up to a point where Fe(III) might be as high as 95% total iron. The proposed method is suitable for Fe(II) determination in bacterial leaching systems, where Fe(II) might be as low as 1% of total iron.     

离子陷阱脱除Fe~(3+)的工艺研究

以铝合金为还原剂,采用离子陷阱进行了去除Na Cl溶液中Fe3+的研究。研究了Na Cl溶液流速、温度、初始Fe3+浓度和Na Cl质量分数等操作条件对Fe3+去除效果的影响规律。结果表明,随着流速减小、温度升高、初始Fe3+浓度增大和Na Cl质量分数增大,Fe3+的脱除率升高。在质量分数为3.5%的Na Cl溶液流量为10L/h,温度为60℃,初始Fe3+浓度为10mg/L时,Na Cl溶液中Fe3+的去除率可达95%以上。     

Phosphorus-Implanted Glass for Radiotherapy: Effect of Implantation Energy

A chemically durable glass that contains a large amount of phosphorus is useful for in situ irradiation of cancers. It can be activated to be a β-emitter with a half-life of 14·3 d by using neutron bombardment. Microspheres of the activated glass that are injected to tumors can irradiate the tumors directly with β-rays without irradiating neighboring normal tissues. In the present study, P⁺ ions in various doses have been implanted into a pure silica glass in a plate form at 200 keV. Almost all the implanted phosphorus is present in the inner region of the glass rather than in the surface region, taking the form of phosphorus colloids for all the doses in the range of 5 × 10¹⁶-1 × 10¹⁸ cm^-2. A large number of amorphous phosphorus colloid particles with diameters of 10-150 nm are formed in the silica glass that has been implanted with a dose of 1 × 10¹⁸ cm^-2; these colloid particles are distributed widely in a layer that is centered at a depth of 200-250 nm. All the investigated glasses hardly release any phosphorus and silicon into water at a temperature of 95°C, even after 7 d. A silica glass that has been implanted with P⁺ ions at 200 keV with a dose of 1 × 10¹⁸ cm^-2 is believed to be useful as a radiotherapy glass with sufficient phosphorus content and high chemical durability.     

石英砂高温焙烧-酸洗除铁动力学研究

采用高温焙烧-酸洗方法除石英砂Fe杂质,实验结果表明,900℃焙烧最佳时间为180 min;焙烧后90℃水浴混酸酸洗360 min,石英砂中Fe去除率可达88.3％,Fe杂质含量降为34.61μg/g.通过扫描电子显微镜(SEM)表征该方法处理前后石英砂形貌,结果表明处理后石英砂表面出现明显裂纹和蚀坑,有助于酸液浸入颗粒内部,提高Fe去除率.利用收缩未反应芯模型对实验数据拟合,该酸洗反应控速步骤为产物内扩散控制,焙烧处理后酸洗反应更快,Fe去除率更高,活化能更低.经900℃焙烧,保温180 min处理石英砂,酸洗反应的活化能是30.88 kJ/mol,未焙烧酸洗反应活化能为36.18 kJ/mol,焙烧后酸洗反应活化能下降了17.2％,说明焙烧处理有利于石英砂的酸洗.     

Synthesis and Photoluminescence of Silica Nanowires Grown on Si Substrate

A new simple method was developed to synthesize silica nanowires by physical thermal evaporation of a mixture of silica particles and iron trichloride. The silica nanowires have diameters from 30 to 50 nm, and lengths of ~10 μm, with iron particles at their tips. The growth mechanism of the amorphous silica nanowires follows vapor–liquid–solid model. A broad blue–green photoluminescence band with defined maximum peak energy of ~2.45 eV is observed at room temperature revealing that the silica nanowires could have potential applications in optoelectronic devices.     

Determination of copper,iron, nickel and zinc in gasoline by FAAS after sorption and preconcentration on silica modified with 2-aminotiazole groups

Silica gel chemically modified with 2-aminotiazole groups (SiAT), was used for preconcentration of cupper, zinc, nickel and iron from gasoline, normally used as a engine fuel. Surface characteristics and surface area of the silica gel were obtained before and after chemical modification using FT-IR, Kjeldhal and surface area analysis (B.E.T.). The retention and recovery of the analyte elements were studied by applying batch and column techniques. The experimental parameters, such as shaking time in batch technique, flow rate and concentration of the eluent (HCl—0.25–2.00 mol l⁻¹) and the amount of silica, on retention and elution, have been investigated. Detection limits of the method for cupper, iron, nickel and zinc are 0.8, 3, 2 and 0.1 μg l⁻¹, respectively. The sorption–desorption of the studied metal ions made possible the development of a preconcentration method for metal ions at trace level in gasoline using flame AAS for their quantification.