头发铅含量测定的应用价值评价

调查了125例2－5岁儿童铅中毒状况，测定其全血铅含量和头发铅含量，以全血铅含量为标准，应用诊断试验评价方法评价头发铅测定的应用价值。结果表明，该试验的灵敏度可达88．3％，应用串联试验，即同时测定头发中锌、铁、钙含量，可将该试验的特异度提高至81．8％，阳性预测值达69．6％，阴性预测值达78．8％。     

Interaction of nitric oxide with cobalt(II) phthalocyanine: kinetics, equilibria and electrocatalytic studies

The coordination of nitric oxide (NO) to cobalt(II) phthalocyanine (CoPc) in dimethyl sulphoxide (DMSO) has been studied. CoPc coordinates with NO in a 1:1 ratio, forming a CoPc(NO) species. The IR band observed at 1680 cm⁻¹ is assigned to the coordinated NO. In the presence of excess NO, pseudo first order kinetics were followed. The observed rate constant, k_f, was determined to be 15.0±0.3 dm⁻³ mol⁻¹ s⁻¹ and the equilibrium constant was K=5.4±0.4×10⁴dm³ mol⁻¹. Solution or adsorbed CoPc catalyses the reduction of NO. The products of reduction include NH₃ and NH₂OH.     

Synthese und Struktur des ersten ternären Blei(II)-Oxocuprats(I): PbCu2O2

Synthesis and Structure of the First Ternary Lead(II) Copper(I) Oxide: PbCu₂O₂ PbCu₂O₂ can be prepared by solid state reaction or by precipitation from a basic aqueous solution. Single crystals of the new compound were prepared by recrystallisation from a molten mixture (PbO? Cu₂O) and investigated by X-ray diffractometer technique. PbCu₂O₂ crystallizes isotypically with the homologue silver compound PbAg₂O₂ (monoclinic with a = 8.22₃ Å, b = 8.28₉ Å, c = 6.01₅ Å, β = 132.6₂°, Z = 4, space group C? C 1 2/c 1). The crystallographic data from the X-ray investigation are reported. The structure is built by endless [PbO_4/4]- and [CuO_2/4]-chains. Pb²⁺ has a one-sided asymmetric coordination with four next oxygen neighbours and Cu⁺ forms a stretched dumbbell with two oxygen atoms.     

Studies on tetra-amine phthalocyanines

Metal(II) tetranitro phthalocyanines of cobalt, nickel and copper are synthesized in pure state by a novel modified method. The complexes are characterized using elemental, electronic and IR spectral studies. Pure metal(II) tetra-amino phthalocyanines of cobalt, nickel and copper are synthesized by reducing the nitro groups of the above complexes using sodium sulphide. These complexes are also characterized by elemental, electronic, IR spectral and magnetic susceptibility measurements. The nature of the electrical conductivities of the above three metal(II) tetra-amino phthalocyanine derivatives are studied in the temperature range 303-473 K and the data are presented. Among the effect of various substituent groups on the electrical conducting property of phthalocyanine, amine group substituent on the peripheral benzene ring of the phthalocyanine molecule has been found to increase electrical conductivity to a greatest extent. These complexes showed about 10⁵-10⁶ times higher electrical conductivities compared to their parent phthalocyanine compounds.     

Phase transitions in ternary caesium lead bromide

Phase transitions in ternary caesium lead bromide (CsPbBr₃) were studied by means of DSC, TMA and high temperature X-ray diffraction. The samples were prepared from the solution by water evaporation and from the melt. on the DSC curves as well as on the temperature dependence of the lattice constants of CsPbBr₃ only two effects were found belonging to the earlier published phase transitions at 88 and 130°C and no further effects. Linear thermal expansion coefficient α of individual CsPbBr₃ modifications were calculated from both TMA and high temperature X-ray diffraction. The structural parameters of the room temperature orthorhombic phase were refined and the results are presented. CsPbBr₃ prepared from the solution contained about 10% of CsPb₂Br₅ and so the DSC curve of pure CsPb₂Br₅ was also measured and an effect at a temperature of 68.5°C was found. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and crystal structure of ternary molybdate compound K<Subscript>5</Subscript>Pb<Subscript>0.5</Subscript>Hf<Subscript>1.5</Subscript>(MoO<Subscript>4</Subscript>)<Subscript>6</Subscript>

Single crystals of triple molybdate of composition 5:1:3 K₅Pb_0.5Hf_1.5(MoO₄)₆ have been grown and their crystal structure has been solved from X-ray diffraction data (an automated diffractometer X8 APEX, MoK _α -radiation, 2173 F(hkl), R = 0.0321). Trigonal unit cell parameters are: a = b = 10.739(2) Å, c = 37.933(9) Å; V = 3789(1) ų, Z = 6, ρ_calc = 4.014 g/cm³, space group \(R\bar 3\). Three-dimensional mixed framework of the structure is formed by two types of MoO₄ tetrahedra and Pb and Hf octahedra linking via common O-vertices. Potassium atoms of three types occupy large vacancies in the framework.     

Blood lead monitoring in Italy: Assessment of the quality of results obtained between 1992 and 1994

Between 1992 and 1994, a new screening campaign for blood Pb monitoring in the Italian general population was carried out. Since the first campaign (started in 1978, in accomplishment of the European Community Directive 77/312/EEC) a working group of the Laboratory of Clinical Biochemistry at the Italian National Institute of Health (Istituto Superiore di Sanità), as the Reference Centre (RC), has coordinated the activity of various laboratories spread over the national territory. Appropriate quality assurance procedures, including an external quality assessment scheme (EQAS), were elaborated. Within the EQAS, three or four trials were carried out every year. Each laboratory participating in the trial analyzed eight control samples prepared from cow blood at different Pb concentrations. The results obtained by each peripheral laboratory and the RC between 1992 and 1994 have been compared by regression analysis. The same statistical method was adopted to compare the results obtained by each peripheral laboratory and the RC in the duplicate analysis of about 10 per cent of the human samples collected during the 1992–1994 monitoring campaign. There was no evidence of systematic differences between the regression lines obtained on control and human samples. In spite of the lower Pb concentration in the control samples analyzed during the 1992–1994 campaign, the analytical performance of the laboratories was better than that obtained in the previous screening campaign (1985–1986). Blood Pb levels observed in human samples collected between 1992 and 1994, confirm the downward time trend observed in the campaigns carried out in 1978–1979, 1980–1981 and 1985–1986. This study confirms that the results obtained in an EQAS are representative of the actual performance in the analysis of real (human) samples.     

Selective Transport of Lead(II) and Strontium(II) Through a Crown Ether-Based Polymer Inclusion Membrane Containing Dialkylnaphthalenesulfonic Acid

New polymer inclusion membranes (PIMs) containing 18-membered crownethers and dialkylnaphthalenesulfonic acid are proposed for Sr2+ and Pb2+removal from nitric acid solutions. The influence of source phasecomposition and stripping agents was characterized and permeabilitycoefficients were calculated. The PIMs are easy to prepare and may be usefulin separation and concentration procedures for these cations from complexmixtures such as nuclear waste. Long-term stability was obtained for atleast several weeks of constant use during which no significant change ofpermeability was observed.     

Solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles as ionophore

A novel solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles (NanoCoPc) as ionophore was fabricated without any need of auxiliary materials (such as membrane matrix, plasticizer, and other additives). The electrode was prepared by simple drop-coating NanoCoPc colloid on the surface of a glassy carbon electrode. A smooth, bright and blue thin film was strongly attached on the surface of the glassy carbon electrode. The electrode showed high selectivity for ascorbic acid, as compared with many common anions. The influences of the amount of NanoCoPc at the electrode surface and pH on the response characteristics of the electrode were investigated. To overcome the instability of the formal potential of the coated wire electrode, a novel electrochemical pretreatment method was proposed for the potentiometric sensor based on redox mechanism. This resulting sensor demonstrates potentiometric response over a wide linear range of ascorbic acid concentration (5.5 × 10⁻⁷ to 5.5 × 10⁻² M) with a fast response (<15 s), lower detection limit (ca. 1.0 × 10⁻⁷ M), and a long-term stability. Furthermore, microsensors based on different conductors (carbon fiber and Cu wire) were also successfully fabricated for the determination of practical samples.     

MCM-41介孔分子筛共价键联钴酞菁的制备，表征及性质

采用两种方法将钴酞菁配合物共价联接到介孔分子筛MCM-41的表面：(1) 在MCM-41表面联接含伯胺的有机侧链；(2) 是在MCM-41表面联接含仲胺的有机侧链。含氯磺酸基的钴酞菁与胺反应形成磺酰胺。对得到的主客体化合物用多种物化手段和催化反应进行了表征。结果表明，钴酞菁以单体形式固定在介孔分子筛MCM-41的孔道壁上，在反应条件下固载后的钴酞菁具有高催化活性，同时表现出良好的稳定性，多次重复使用活性没有明显的改变。