全自动QuEChERS样品制备系统结合高效液相色谱-串联质谱法检测植物源性食品中34种农药残留

建立了全自动QuEChERS样品制备系统结合高效液相色谱-串联质谱（HPLC-MS/MS）同时检测植物源性食品中34种农药残留的分析方法。方法利用全自动QuEChERS样品制备系统涡旋振动和离心功能，将手动QuEChERS方法中样品提取和分散固相萃取相结合；优化了操作参数及前处理步骤，在多反应监测（MRM）模式下检测，基质匹配外标法定量。从方法学验证角度对全自动QuEChERS法与手动QuEChERS法进行了比较。结果表明：该方法中大多数农药在一定范围内呈现良好的线性关系，相关系数（R²）均大于0.99，检出限为0.76~3.60 μg/kg，定量限为2.28~10.80 μg/kg，加标回收率为53.0%~125.2%，相对标准偏差（RSD）<15.9%（n=5）。该方法与手动QuEChERS法的方法验证比对结果显示差异不明显，用于植物源性食品中多农药残留检测可有效降低劳动强度和出错概率。     

Dynamik linearer Molekülanionen in den Hydrogensulfiden von Natrium,Kalium und Rubidium: Differential-Scanning-Kalorimetrie,Röntgen- und Neutronenbeugung

Dynamical Behaviour of Linear Molecular Anions in the Hydrogensulfides of Sodium, Potassium and Rubidium: Differential Scanning Calorimetry, X-ray and Neutron Diffraction Hydrogensulfides of the alkali metals M ? Na, K, Rb were prepared in autoclaves by the reaction of the corresponding metals with H₂S and D₂S, respectively, in the temperature range from 50°C to 150°C. Differential scanning calorimetry, X-ray and neutron diffraction methods reveal that both, the HS^?-and DS^?-compounds occur in three crystalline modifications with HT ? high-, MT ? medium- and LT ? low-temperature form: The temperatures and enthalpies for the changes of modifications of the H- and D-compounds are given and the atomic arrangements revealed mainly by neutron diffraction data are discussed, in relation to, for example, size of cations.     

3，9－二羟乙基－3＇，9＇－二苯甲基－1，5，7，11－四氧杂螺环［5，5］十一烷的合成和聚合反应

从两二酸二乙酯、氯乙酸乙酯和氯苄出发，经ＬｉＡｌＨ４还原，合成新的二元醇，进而合成新的螺环化合物：３，９－二羟乙基－３＇，９＇－二苯甲基－１，５，７，１１－四氧杂螺［５，５］十一烷．该化合物的结构由它的氢和碳－１３核磁共振谱、红外光谱和元素分析得到证明．该单体在三氟化硼乙醚络合物的作用下进行开环聚合反应．由于环上四个取代基的稳定作用，聚合物的收率比较低（产率１０％左右）．通过对聚合物的结构分析，提出了这一单体的阳离子开环聚合反应机理．对随聚合温度升高，聚合物中酯基／苯基的克分子比降低，以及本体聚合时得到交联聚合物等一系列现象作了探讨．     

Kinetics and mechanism of thermal decomposition of hydroxylammonium nitrate

The kinetics of thermal decomposition of melted hydroxylammonium nitrate have been investigated by the rate of heat production in the temperature range 84.8–120.9°C. The decomposition proceeds with autocatalysis and up to 60 % of conversion the rate of the process increases proportionally to the square of the degree of decomposition. The initial rate is proportional to the square of the concentration of HNO₃ formed due to dissociation of the salt. The activation energy of this process is 15.3±1.8 kcal/mol. It is suggested that the initial stage the process proceeds via interaction between N₂O₃ and NH₃OH⁺, whereas the subsequent acceleration is due to oxidation of NH₃OH⁺ by nitrogen oxides formed as well as by nitrous acid.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1897–1901, November, 1993.     

Preparation and Crystal Structure of Potassium Iron Hydrogen Phosphate,KFe3(HPO4)2(H2PO4)6 · 4 H2O

Single crystals of potassium iron hydrogen phosphate, KFe₃(HPO₄)₂(H₂PO₄)₆ · 4 H₂O, were prepared hydrothermally by heating a mixture of Fe₂O₃, H₃PO₄ and K₂CO₃ with a small amount of water. It crystallizes monoclinic, space group C2/c (N° 15 Int. Tab.) with Z = 4 and a = 1701(2), b = 960.4(5), c = 1750(1) pm, β = 90.88(7)°. The crystal structure was solved by using 1716 unique reflections F₀ > 4σ(F₀) with a final wR2 value of 0.126 (SHELXL-93). The main feature of the crystal structure are layers formed by PO₄-tetrahedra around the FeO₆-octahedra parallel to (001). K⁺ and H₂O molecules connect these layers. Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), Charge Distribution (CHARDI) and the Madelung Part of Lattice Energy (MAPLE) are calculated for the title compound. The existence of hydrogen bonds is confirmed by these calculations.     

Zur Kenntnis des Natrium-tetrahydroxoaluminat-chlorids Na2[Al(OH)4]Cl

On the Sodium Tetrahydroxoaluminate Chloride Na₂[Al(OH)₄]Cl The hitherto unknown compound Na₂[Al(OH)₄]Cl was prepared by crystallisation from a NaCl containing sodium aluminate solution. According to the X-ray single crystal investigation (tetragonal, space group P4/nmm, a = 7.541 Å, c = 5.059 Å, Z = 2) the compound represents the first example of a crystalline hydroxoaluminate with monomeric [Al(OH)₄]^? anions. Cl^? shows a quadratic anti prismatic coordination to 4 Na⁺ and over hydrogen bonds to 4 O^2? while Na⁺ is octahedrally coordinated by 4 O^2? and 2 Cl^? (axial). The results of the crystal structure analysis are confirmed by ²⁷Al and ²³Na MAS NMR investigations. Na₂[Al(OH)₄]Cl decomposes at about 200°C without intermediates under formation of β-NaAlO₂ and NaCl.     

包覆型纳米铜-银双金属粉研究

目前,导电胶或者电磁波屏蔽涂料用的导电性填料主要有三类,一是铜粉,二是银粉,三是铜-银双金属粉。铜粉具有来源广、价格低廉、导电性好等优点,但其抗氧化性能弱;银粉导电性与抗氧化性好,但其资源日益匮乏。大量的研究试图通过对铜粉进行表面改性来提高其性能。表面改性有两种方法,一是包膜处理,用SiO2溶胶处理铜粉,铜粉抗氧化性能提高,但其表面导电性能大大降低犤1犦;另一类方法是在铜粉表面覆盖一层导电性能与抗氧化性能均佳的银或金而制成双金属粉末犤2～5犦。制取高性能的铜-银双金属粉是该领域的研究重点。目前获得铜-银双金属粉的方…     

液相还原法制备超细球形镍粉

本文论述了液相还原法直接制备高振实密度球形镍粉的新工艺。采用NiSO_4·5H_2O为原料,利用NaOH调节溶液的pH值并形成Ni(OH)_2,还原剂采用N_2H_4·H_2O,还原过程中加入晶核引发剂及表面活性剂。采用正交实验表安排实验,对影响镍粉振实密度及粒径的因素进行了极差分析。实验数据表明,溶液中镍的初始浓度对产品质量的影响最大,较优工艺组合条件为:初始Ni~(2+)的浓度1.5mol·L~(-1),NaOH用量为理论量的1.1倍,反应温度80℃,表面活性剂用量为每克镍5mg,晶种添加量为还原剂理论用量的0.1％。新工艺可制备振实密度高达3.0以上、质量中位径为1μm的球形镍粉。     

硼化合物的研究——Ⅴ.氢硼酸π-芳烃-π-环戊二烯基铁的合成和性质

本文研究了氢硼酸根(B_(12)H_(12)~(2-)、B_(10)H_(10)~(1-)、B_(11)H_(14)~-)和π-芳烃-π-环戊二烯基铁阳离子的反应,合成了36个氢硼酸π-芳烃-π-环戊二烯基铁化合物。通过元素分析和红外光谱测定确定了化合物的组成。部份化合物还作了~1H NMR鉴定。对化合物的性质,包括它们的热行为,进行了较详细的研究。DTA仪测得的结果表明,(1)当阳离子相同时,化合物的热稳定性的顺序为:[ArFeC_5H_5]_2B_(12)H_(12)>[ArFeC_5H_5]_2B_(10)H_(10)>[ArFeC_5H_5]B_(11)H_(14);(2)当氢硼酸根相同时,其热稳定性受芳环上取代基的影响。     

基于离子液体的炭材料制备、改性及应用

离子液体因其熔点低、液态温域宽、蒸气压低、热稳定性高、电导率高、电化学窗口宽、结构可设计及对许多化合物的亲和性等系列性能而引起人们广泛关注。离子液体在炭材料制备、改性领域展示出了良好的前景及巨大的应用潜力,可直接作为碳源,经过高温炭化实现杂原子掺杂制备多孔炭材料;离子液体也可充当反应介质和致孔剂,将生物质转化为多孔炭材料;此外,由于离子液体与炭材料相容性较好,可以用于多孔炭材料改性制备炭复合材料。基于离子液体的炭材料在电催化、超级电容器、吸附分离及生物医学等领域具有潜在的应用价值。本文总结了基于离子液体炭材料的制备、改性及应用最新研究进展,并着重介绍了其在能源和环境相关领域的应用。