石墨炉原子吸收光谱法测定矿石中铂、钯、铑、铱

矿石样品铂、钯、铑和铱经铅试金富集,所得金属合粒用硝酸-盐酸溶解,用石墨炉原子吸收光谱法测定矿石样品中铂、钯、铑和铱的含量。在优化的石墨炉工作条件下测得:铂的质量浓度在20～150μg.L-1、钯在15～120μg.L-1、铑和铱在6～100μg.L-1范围内与其吸光度呈线性关系,检出限(3s/k)依次为4.6,4.0,1.5,1.5μg.L-1。方法用于分析了2种矿石国家标准物质(GBW 07341、GBW 07342),测定结果与认定值相符。方法的回收率在87.6%～105.5%之间。测定值的日内和日间相对标准偏差(n=7)分别在2.8%～3.6%和3.5%～4.7%之间。     

氯化亚锡活化-TOPO溶剂萃取分离铑铱及机理研究

在三正辛基氧化膦(TOPO)-乙酸乙酯体系中,应用氯化亚锡活化-溶剂萃取技术选择性分离Rh(Ⅲ)和Ir(Ⅳ),通过萃取铑实现铑铱的分离.考察了nSn/nIr、盐酸浓度对铱萃取率的影响.在相比为1 ∶ 1,nSn/nIr(nSn/nRh)=4,3 mol·L-1盐酸浓度的条件下,通过对含不同浓度铑、铱的料液进行萃取,铑的萃取率达到98%以上,铱的萃取率低于4%.在萃取过程中未能完全分离的铑铱通过HCl与KClO3的混合溶液以及硝酸的反萃实现分离.研究了贱金属的萃取行为,考察了贱金属及金对铑铱萃取分离的影响.将饱和萃取有机相减压蒸馏,通过红外光谱表征,探讨了萃取机理.     

中子活化测定铑中铱

金属铑是铂族元素之一,为灰白色硬质金属。铑与铱均为难熔亲铁元素,性质非常相近,以至于多种化学分离方法都很难使之完全分开。用质谱法测定铑中少量铱已有极导,缺点是灵敏度不高。Kuranov采用特殊的质谱技术提高了灵敏度,然而由于基体和第三种元素的干扰使得准确度下降。Gijbels曾用中子活化加入法避免样品和标样之间由于中子屏蔽所造成的差异。我们用中子活化法测定铑中铱,并按公式求得衰减系数。并测出铑中钌的含量。     

化学简讯

硼氢化钠(NaBH_4)在水溶液内是比较稳定的;但是酸或铁系元素(铁、钴、镍)、铂系元素(钌、铑、钯、锇、铱、铂)的盐可促进硼氢化钠水解,放出氢气。同时相     

湿法连续测定矿石中钌、锇、铂、钯、铑、铱

矿石中铂族元素的测定通常是分三次称样,采用碱熔蒸馏催化比色测定钌、锇;铅试金富集-DDO比色测定铂、钯;催化比色法测定铱,催化极谱法测定铑。在沿用的铅试金法中,铱的结果偏低,主要是由于灰吹时铱在灰皿中损失所致。此外,资料介绍:“铬铁矿样品直接配料试金时,不能将铬铁矿全部分解,需用1.5倍过氧化钠在700℃半熔1小时,再配料试金。”国内试验工作也发现某些铬铁矿按常规配料方案,铑、铱的结果     

鉑族元素和金的纸层析

本文报告用氯化銨、氯化鈉和盐酸作展开剂分离鉑族元素和金的結果。在所采用的条件下,金的比移值最小而铱的比移值最大。若以一元素比移值在不同条件下之改变而论,钌(0.06)和铱(0.03)改变甚少,而钯、铑(均为0.15)、锇、鉑(均为0.26)、金(0.30)改变較大(括弧內系各种条件下最大和最小比移值之差)。     

过渡金属催化二环烯烃加成反应的研究进展

综述了近年来过渡金属催化二环烯烃加成反应的研究进展,主要包括了钌、铑、铱、钯、铜、钴、镍和铁催化二环烯烃的加成反应,并对部分加成反应可能的机理进行了讨论.     

甲酸分解制氢均相催化剂的研究进展

甲酸(HCOOH)具有作为液氢储存材料和清洁制氢的巨大潜力.在过去的十几年中,人们不仅在开发活性更强、更稳定、选择性更强的催化剂方面取得了重大进展,而且提出了氢气释放和储存循环系统的概念.综述了均相催化剂在这一领域的最新进展,重点介绍了钌、铑、铱为代表的贵金属催化剂,同时还涉及铁、钴、镍、铜、铝等非贵金属催化剂.希望本综述对今后开发更好的甲酸脱氢催化体系提供一些见解和思路.     

铑(Ⅲ)与5-Br-PADAP在乙醇-水溶液中的显色反应-吸光光度法测定铑及铑、钯的同时测定

基于在30～35％的乙醇-水溶液中铑(Ⅲ)与5-Br-PADAP形成1:1的有色配合物,提出了一个有较高灵敏度的吸光光度测定铑的方法。适宜pH的范围是5.0～7.0。铑(Ⅲ)-5-Br-PADAP配合物的摩尔吸光系数ε590=9.0×10~4L·mol~(-1)cm~(-1)方法是有较好的选择性,在抗坏血酸、柠檬酸盐和EDTA存在下适当量的钯、铂、钌、铱、锇及其他许多金属离子不干扰铑的测定。也可根据与5-Br-PADAP反应速度的差异同时测定钯和铑。     

电感耦合等离子体发射光谱(ICP-AES)法测定铂金材料中杂质元素

建立了微波消解-电感耦合等离子体原子发射光谱(ICP-AES)法同时测定铂饰品国家标准物质中金、铜、铱、钴、钯、铑、钌7种杂质元素含量的方法.方法中7种元素的检出限为:钯与钌＜0.0001％,其它元素＜0.00062％.经与国家标准物质认定值比对,结果满意.稀释系数95.5％～104.7％.方法测定结果与标准样品认定值一致,可满足铂金材料中杂质元素检测.     

Loss of iridium,osmium and ruthenium from aqueous solutions during storage

Aqueous solutions of iridium are stable (within 3 %) over a four-month storage period in a variety of container types and over a range of acid concentrations. Standard solutions of water-soluble iridium compounds at pH 7 can be employed reliably. Rapid loss of osmium and ruthenium from aqueous solutions at pH 7 means that standard solutions must be used within 1 day of preparation. Nitric acid solutions of osmium and ruthenium should also be avoided. The six plastics studied are unacceptable containers for 0.1 M hydrochloric acid solutions of osmium; 1 M hydrochloric acid is an adequate preservative for osmium solutions for up to two months and for ruthenium solutions for up to four months in glass, quartz or polyethylene containers.     

Determination of Platinum,Palladium, Ruthenium,Rhodium, and Iridium in Ultrabasic Rock from the Great Dyke of Zimbabwe by Inductively Coupled Plasma–Optical Emission Spectrometry

Platinum, palladium, ruthenium, rhodium, and iridum were determined in ultrabasic rock from the Great Dyke of Zimbabwe by inductively coupled plasma optical emission spectrometry. The limits of detection for these elements were less than 7 ng/g. The samples were fused at 1100°C to separate the noble metals which were enriched into a nickel sulfide button and dissolved in hydrochloric acid. The insoluble noble metals were filtered, dissolved in aqua regia in a boiling water bath, and determined by inductively coupled plasma optical emission spectrometry. This method was employed for the characterization of large quantities of ultrabasic rock from the Great Dyke of Zimbabwe.     

手性氨基酸及其衍生物配体在酮不对称氢转移反应中的应用进展

前手性酮的不对称氢转移反应(ATH)是获得手性醇的重要方法.近年来氨基酸及其衍生物在金属Ru,Rh,Ir催化酮的ATH中的应用引起人们关注.就氨基酸、氨基酸酰胺、氨基酸硫代酰胺、氨基酸羟胺酸、氨基酸酰肼、氨基醇及氨基酸羟基酰胺等为配体的金属络合物在ATH中的催化性能进行了综述.     

Polyurethane foam for the extraction of rhodium and its separation from iridium

The rate of reaction of rhodium with thiocyanate at 90 degrees in the presence of lithium chloride or sufficient hydrochloric acid and the subsequent extraction of the metal from hydrochloric acid medium by polyether-type polyurethane foam was investigated. The effect of the chloride salts of different cations decreased in the order Li(+) > Na(+) > K(+) indicating that Rh(SCN)(6)(3-) is extracted through a simple solvent-extraction mechanism rather than the "cation-chelation" mechanism. The separation of rhodium and iridium was also examined and the results indicated that in the presence of 5-fold excess of iridium, an average of 95 +/- 2% iridium remained in the aqueous phase while an average of 93 +/- 2% rhodium was retained by the foam.     

Nanocrystals,Nanorods and other Nanostructures of Nickel,Ruthenium, Rhodium and Iridium prepared by a Simple Solvothermal Procedure

The solvothermal decomposition of nickel acetate in n-octylamine medium at 250 °C gives rise to nickel nanostructures while in a hydrocarbon medium NiO nanostructures are obtained. It has been possible to obtain nickel nanorods of 12–15 nm diameter by this means. By carrying out the reaction at a slightly higher temperature, ultra-thin single-crystalline sheets of nickel are obtained. The nanorods and the thin sheets, with the FCC structure, are both ferromagnetic at room temperature, with the nanorods exhibiting high coercivities. It has been possible to obtain ruthenium, rhodium and iridium nanostructures by carrying out the decomposition of the respective metal acetylacetonates in a hydrocarbon (decalin or toluene) or an amine (n-octylamine or oleylamine) around 300 °C. Nanorod formation is favored by linear long-chain amines. The method described by us to prepare the nanostructures of nickel, ruthenium, rhodium and iridium is simple and straightforward compared to the literature procedures, the preparation of single-crystalline thin sheets of nickel by such a solution route being noteworthy. The nanostructures prepared in the amine media could be readily dispersed in hydrocarbon solvents. Dedicated to Professor Dr. Günther Schmid     

Nickel‐Catalyzed Asymmetric Transfer Hydrogenation of Olefins for the Synthesis of α‐ and β‐Amino Acids

The field of asymmetric (transfer) hydrogenation of prochiral olefins has been dominated by noble metal catalysts based on rhodium, ruthenium, and iridium. Herein we report that a simple nickel catalyst is highly active in the transfer hydrogenation using formic acid. Chiral α‐ and β‐amino acid derivatives were obtained in good to excellent enantioselectivity. The key toward success was the use of the strongly donating and sterically demanding bisphosphine Binapine.     

金属镁中杂质元素的快速测定

以盐酸溶液(1 1)溶解金属铗样品，用电感耦合等离子体原子发射光谱(ICP—AES)法同时测定金属镁样品中的杂质元素铁、硅、锰、铝、铜和镍。采用标准溶液与样品溶液基体相一致的方法消除基体干扰。对标准样品进行测定，测定结果与标准值基本一致，相对标准偏差小于7％。t检验结果证明，该方法不存在系统误差。     

湿法消解-电感耦合等离子体原子发射光谱(ICP-AES)法测定含铑废催化剂冶金废水中铑

摘 要：建立了硫酸、过氧化氢湿法消解、ICP-AES测定铑派克洗水铑的含量的分析方法。确定了硫酸碳化有机物,过氧化氢溶解煮沸,氢氟酸除硅,于4mol/L盐酸体系,碲共沉淀富集铑,10%盐酸介质,电感耦合等离子体发射光谱仪测定铑量。在选定条件下,测定含铑有机物洗水中0.0003 g/L～0.010 g/L的铑,相对标准偏差（RSD,n=7）和加标回收率分别为：铑0.545%～2.91%和99.62%%～100.55%。。方法准确、快速、简便,测定结果与火试金富集分析方法结果吻合。     

A new solvent extraction scheme for the separation of platinum,palladium, rhodium and iridium

A new scheme is proposed for the separation of platinum, palladium, rhodium and iridium in hydrochloric acid solutions, by solvent extraction. Platinum and palladium are complexed with 2-mercaptobenzothiazole and potassium iodide and simultaneously extracted into chloroform, thus separating them from rhodium and iridium. Palladium is separated from platinum by extracting its dimethylglyoxime complex into chloroform, while rhodium is separated from iridium by extracting its 2-mercaptobenzothiazole complex into chloroform after reduction with tin(II) chloride.     

The rapid isolation and determination of iridium after simultaneous liquid-liquid extraction and determination of platinum,palladium, rhodium and gold

The proposed method provides a rapid isolation of iridium form the other noble metals, as well as from Ni, Cu, Fe, Cr, Co and Na. The scheme comprises an initial removal of ruthenium and osmium by volatilization of their tetroxides followed by the simultaneous extraction of platinum, palladium, rhodium and gold as their 2-mercaptobenzothiazole—tin(II) chloride complexes into chloroform. Iridium in the raffinate is complexed by the same reagent system, after boiling, and extracted into chloroform. The extracts after evaporation of the solvent are converted to hydrochloric acid solutions and the noble metals are determined by atomic absorption spectrometry. Satisfactory results are obtained for various noble metal solutions, and for a solid platiniferous sample.