微波消解电感耦合等离子体发射光谱法测定塑料中铅和镉

采用微波消解技术溶样，ICP-AES法测定了塑料中的铅和镉。通过对消解试剂和微波温度程序的研究，建立了塑料样品的微波消解方法。该方法与传统马弗炉高温灰化消解方法比较，具有准确、简便、快速、省试剂、污染少、消解完全等优点。方法回收率为93％～106％，相对标准偏差(n=7)均小于2％。实际样品对比分析结果表明，方法具有良好的准确度，适于多种塑料材料中铅和镉的快速分析。     

微波消解-分光光度法测定石油焦中的硅

重点研究了微波消解石油焦样品的方法,详细考察了微波消解时样品的最佳用量、消解压力、消解功率、消解时间,建立了最佳微波消解程序：在样品处理中也采用了常规溶样方法,并分别用两种样品处理方法测定石油焦中的硅。结果表明两种方法测定结果基本吻合,样品测定的RSD小于3．85％,加标回收率在97％～103％之间,但微波消解法的溶样速度是常规法的10倍。实验结果表明,微波消解分光光度法测定石油焦中的硅是一种快速、准确且无环境污染的绿色环保方法,具有一定的实用价值。     

微波消解-分光光度法测定石油焦中的钒

研究了用微波消解分光光度法测定石油焦中的钒。在石油焦样品处理中采用了常规溶样及微波消解两种方法。重点研究了微波消解石油焦样品的方法,详细考察了微波消解时样品的最佳用量、消解压力、功率、时间,建立了最佳微波消解程序。结果表明两种方法测定结果基本吻合。样品测定的RSD小于4、02％,加标回收率均在98．6％～102．7％之间,但微波消解法的溶样速度是常规法的10倍。钒的线性范围为0～8．0g／L。结果表明,微波消解分光光度法测定石油焦中的钒是一种快速、准确且无环境污染的方法。     

微波消解凯氏定氮法快速测定酱油中全氮

研究了凯氏定氮法测定酱油中全氮时样品的微波消解方法，进行了微波消解条件的选择及消解结果精密度试验，并与国家标准方法对比，验证了方法的准确度。试验结果表明，消解完全仪需20min，相对标准偏差均小于2%（n=7），回收率范围为96%～103%，经t检验，微波溶样法与国家标准凯氏定氮法的测定结果无显著性差异。     

微波消解—氟离子选择电极法测定树叶中氟离子含量

采用微波消解处理样品,氟离子选择电极法测定了树叶中氟离子含量;通过正交实验考察了微波功率、消解时间、固液比、冷却时间等条件对微波消解的影响,对消解试剂和微波消解条件进行了筛选和优化。结果表明,其相对标准偏差小于0.46%,加标回收率在95.5%~103.3%之间。该法简单快速、准确可靠,对测定植物树叶中氟离子含量十分有效。     

等离子体发射光谱法测定城市污泥中重金属

采用微波消解技术消解处理样品,建立了等离子体发射光谱法同时检测城市污泥中微量金属元素Cu、Zn、Ni、Cd、Cr、K、B及Pb的方法。讨论了微波消解液、消解参数对消解效果的影响,在最佳实验条件下,微波消解法各元素测定结果的相对标准偏差为1．06％-3．20％（n=6）,加标回收率为93．1％-104．0％。结果表明该方法精密度高,准确性好,快速简单,适于城市污泥中的重金属的测定。     

微波消解-电感耦合等离子体质谱(ICP-MS)法测定纳米银抗菌产品中多种微量元素

建立了微波消解-电感耦合等离子体质谱(ICP-MS)法测定4种纳米银抗菌产品中多种微量元素的分析方法。比较了湿法消解和微波消解这两种样品前处理方法对样品测定的影响,探讨了消除汞记忆效应的方法,并研究了待测元素的质谱干扰的消除。实验结果表明,采用Au(100μg/L)+HCl(2%)能较好地消除Hg的记忆效应。与湿法消解相比,微波消解可短时间消解样品并获得好的Hg回收率。在优化ICP-MS条件后,各元素线性相关系数均大于0.999。采用微波消解-ICP-MS法对样品进行加标回收,样品加标回收率在84.0%~109%,相对标准偏差在0.97%~13.2%。方法快速、简便,能够满足纳米银抗菌产品中微量元素的定量测定。     

超级微波消解－石墨炉原子吸收光谱法测定香菇中的镉

为建立一种快速批量检测香菇中镉的方法,建立了超级微波消解－石墨炉原子吸收光谱法测定香菇中镉含量的方法。分别采用湿法消解、普通微波消解和超级微波、传统微波和湿法消解技术前处理香菇标准物质样品,对比消解效果,优化超级微波消解技术的酸体系和消解最终温度。;采用石墨炉原子吸收光谱仪法测定,优化基体改进剂、灰化温度等工作参数,确定仪器最佳检测条件,验证分析方法的准确性和稳定性。结果表明,超级微波消解优于湿法消解和传统微波消解技术,准确性和重复性最佳,大幅减少用酸量的同时更加安全、高效,避免样品污染。在最优分析方法条件下,镉在0~4.0 μg/L范围内所得回归方程线性关系良好,相关系数(R)为0.9994,方法检出限为0.001 mg/kg,精密度RSD为1.4%~2.5%。超级微波消解－石墨炉原子吸收光谱法检测的探索与应用超级微波消解优于湿法消解和传统微波消解技术,大幅减少用酸量的同时更加安全、高效,避免样品污染,为农产品镉含量批量检测提供可靠的方法支撑。     

微波消解-电感耦合等离子体质谱法（ICP-MS）测定淡水产品中多种金属元素

摘要：建立了微波消解-电感耦合等离子质谱（ICP-MS）同时测定淡水产品多11种金属元素的定量分析方法。比较了传统的湿法消解和微波消解两种消解方式对淡水产品测定影响。实验结果表明,微波消解方法不仅能够快速地将待测元素从淡水产品基体中释放出来,而且能够很好地保留在消解液中,待测元素的回收率较高。所建立方法测定了GBW10024（GSB-15）扇贝和GBW10051（GSB-29）猪肝标准物质,所得结果与标准值吻合度较高。采用微波消解-ICP-MS法测定市售的淡水产品中多种金属元素,其样品回收率在91.20%~110.81%。该方法快捷、准确、灵敏高,满足大批量淡水产品中金属元素分析测定要求,可为公安部门维护“食药环”领域安全稳定提供依据。     

微波消解-连续流动分析法测定肉类食品中的磷

肉类食品是重要的磷来源,随着磷酸盐在肉制品生产加工中的广泛应用,它在食品中的安全性也备受关注。因此,建立一种肉类食品中磷快速定量测定方法具有重要意义。通过优化肉类样品的微波消解体系,建立了肉类样品磷含量检测的微波消解-连续流动分析方法。研究结果表明,硝酸可以作为微波消解酸体系,证明硝酸用量为6 mL、样品量0.1 g、赶酸温度210℃和消解液稀释倍数100倍时,为较优的微波消解条件。微波消解处理后的样品利用连续流动分析仪进行外标法定量检测。测定结果表明,建立的微波消解-连续流动分析法的检测线性范围为0～4 mg/L,线性相关系数为0.999 4,样品回收率为92.5%～103%,相对标准偏差RSD小于5%(n=10)。方法适用于肉类食品中磷的快速、批量检测。     

Sc2MgGa2 and Y2MgGa2

Scandium magnesium gallide, Sc₂MgGa₂, and yttrium magnesium gallide, Y₂MgGa₂, were synthesized from the corresponding elements by heating under an argon atmosphere in an induction furnace. These intermetallic compounds crystallize in the tetragonal Mo₂FeB₂‐type structure. All three crystallographically unique atoms occupy special positions and the site symmetries of (Sc/Y, Ga) and Mg are m2m and 4/m, respectively. The coordinations around Sc/Y, Mg and Ga are pentagonal (Sc/Y), tetragonal (Mg) and triangular (Ga) prisms, with four (Mg) or three (Ga) additional capping atoms leading to the coordination numbers [10], [8+4] and [6+3], respectively. The crystal structure of Sc₂MgGa₂ was determined from single‐crystal diffraction intensities and the isostructural Y₂MgGa₂ was identified from powder diffraction data.     

Electrochemical study of (NEt4)2Cl2FeS2MoS2 and (NEt4)2Cl2FeS2MoS2FeCl2

Summary The ability of [MoS₄]^2–, anions to be used as ligands for transition metal ions has been widely demonstrated, especially with Fe²⁺. The present study has been restricted to linear complexes such as (NEt₄)₂ [Cl₂FeS₂MoS₂] and (NEt₄)₂[Cl₂FeS₂MoS₂FeCl₂]. Their electrochemical properties are described: upon electrochemical reduction, these compounds yield MoS₂, as a black precipitate, and an iron complex in solution, assumed to be [SFeCl₂]^2–. The electrochemical reduction goes through two electron transfers, coupled with the breakdown of the molecular skeleton: a DISPl and an ECE mechanism. Depending on the solvent, the following equilibrium may be observed: [Cl₄Fe₂MoS₄]^2–[Cl₂FeMoS₄]^2–+FeCl₂. The equilibrium constant, K_D, was evaluated by differential pulse polarography. K_D is tightly related to the donor number of the solvent.     

Zur Kenntnis der Dialkalimetalldichalkogenide β-Na2S2, K2S2, α-Rb2S2, β-Rb2S2, K2Se2, Rb2Se2, α-K2Te2, β-K2Te2 und Rb2Te2

On Dialkali Metal Dichalcogenides β-Na₂S₂, K₂S₂, α-Rb₂S₂, β-Rb₂S₂, K₂Se₂, Rb₂Se₂, α-K₂Te₂, β-K₂Te₂ and Rb₂Te₂ The first presentation of pure samples of α- and β-Rb₂S₂, α- and β-K₂Te₂, and Rb₂Te₂ is described. Using single crystals of K₂S₂ and K₂Se₂, received by ammonothermal synthesis, the structure of the Na₂O₂ type and by using single crystals of β-Na₂S₂ and β-K₂Te₂ the Li₂O₂ type structure will be refined. By combined investigations with temperature-dependent Guinier-, neutron diffraction-, thermal analysis, and Raman-spectroscopy the nature of the monotropic phase transition from the Na₂O₂ type to the Li₂O₂ type will be explained by means of the examples α-/β-Na₂S₂ and α-/β-K₂Te₂. A further case of dimorphic condition as well as the monotropic phase transition of α- and β-Rb₂S₂ is presented. The existing areas of the structure fields of the dialkali metal dichalcogenides are limited by the model of the polar covalence.     

The alkali hypophosphites KH2PO2, RbH2PO2 and CsH2PO2

The structures of the hypophosphites KH₂PO₂ (potassium hypophosphite), RbH₂PO₂ (rubidium hypophosphite) and CsH₂PO₂ (caesium hypophosphite) have been determined by single‐crystal X‐ray diffraction. The structures consist of layers of alkali cations and hypophosphite anions, with the latter bridging four cations within the same layer. The Rb and Cs hypophosphites are isomorphous.     

Formal [(2+2)+2] and [(2+2)+(2+2)] nonconjugated dienediyne cascade cycloadditions

[reaction: see text] Fluoranthene 2 and heptacycle 3 are easily accessible from the reaction of diyne 1 and norbornadiene (NBD) in the presence of the rhodium catalyst. The unusual [(2+2)+(2+2)] adduct 3 was confirmed by the X-ray crystal structure analysis.     

Crystal Structures of [Bu2Sn(O2PPh2)2], [Ph2Sn(O2PPh2)2], and [PhClSn(O2PPh2)OMe]2. Raman Spectra of [Ph2Sn(O2PPh2)2] and [PhClSn(O2PPh2)OMe]2

[(n‐Bu)₂Sn(O₂PPh₂)₂] ( 1 ), and [Ph₂Sn(O₂PPh₂)₂] ( 2 ) have been synthesized by the reactions of R₂SnCl₂ (R=n‐Bu, Ph) with HO₂PPh₂ in Methanol. From the reaction of Ph₂SnCl₂ with diphenylphosphinic acid a third product [PhClSn(O₂PPh₂)OMe]₂ ( 3 ) could be isolated. X‐ray diffraction studies show 1 to crystallize in the monoclinic space group P2₁/c with a = 1303.7(1) pm, b = 2286.9(2) pm, c = 1063.1(1) pm, β = 94.383(6)°, and Z = 4. 2 crystallizes triclinic in the space group , the cell parameters being a = 1293.2(2) pm, b = 1478.5(4) pm, c = 1507.2(3) pm, α = 98.86(3)°, β = 109.63(2)°, γ = 114.88(2)°, and Z = 2. Both compounds form arrays of eight‐membered rings (SnOPO)₂ linked at the tin atoms to form chains of infinite length. The dimer 3 consists of a like ring, in which the tin atoms are bridged by methoxo groups. It crystallizes triclinic in space group with a = 946.4(1) pm, b = 963.7(1) pm, c = 1174.2(1) pm, α = 82.495(6)°, β = 66.451(6)°, γ = 74.922(6)°, and Z = 1 for the dimer. The Raman spectra of 2 and 3 are given and discussed.     

Die Photoionenspektren von SCl2, S2Cl2 und S2Br2

Photoionization Mass Spectra of SCl₂, S₂Cl₂, and S₂Br₂ Photoionization mass spectra of SCl₂, S₂Cl₂, and S₂Br₂ have been measured. Heats of formation, bond energies, and ionization potentials of fragments have been calculated from appearance potentials.