二次旋转设计和反向人工神经网络在铅、镉、汞、镍同时测定中的应用

利用二次通用旋转组合设计法建立了吸光度与显色剂，增敏剂用量及pH 值之间的数学模型，进而得出使吸光度最大的显色剂用量，增敏剂用量及PH值，在优化的基础上，用B－P人工地Pb,Cd,Hg,Ni同时测定的数据进行解析，并与经典最小二乘法进行了对比，结果较准确。     

湖南省湘潭市1038例儿童血铅调查

于 2 0 0 0年 3月～ 2 0 0 1年 6月在湖南省湘潭市对 1 0 38例 1～ 8岁儿童进行了血铅抽样调查。结果显示 2 85例儿童血铅 >1 0 0 μg/L ,占调查人数的 2 7 7%。男女童之间血铅水平无显著差异P >0 0 5。高血铅年龄分布在 2岁组、 6岁年龄组 ,与其他年龄组比较有显著差异P <0 0 5。工业区儿童血铅水平高于市中心区P <0 0 1 ,农村郊区儿童血铅水平最低。本调查为湖南湘潭地区环境治理提供了科学依据。     

Flow injection system for the on-line preconcentration of Pb by cloud point extraction coupled to USN–ICP OES

A novel method for the determination of Pb by on-line cloud point extraction coupled to inductively coupled plasma optical emission spectrometry with ultrasonic nebulization (USN–ICP OES) is presented. The cloud point system was formed in the presence of non-ionic micelles of polyethyleneglycolmono-p-nonylphenylether (PONPE 7.5) and was retained in a minicolumn filled with particles of PTFE. Since the micelles of PONPE were able to extract Pb from the solutions, the use of a complexing reagent was not necessary. Afterwards, the surfactant-rich phase containing the analyte was removed from the minicolumn with nitric acid and introduced into the ultrasonic nebulizer. A total enhancement factor of 150 was obtained for a preconcentration time of 3.3 min, with respect to the direct determination of Pb by conventional ICP OES. The values of the detection (3σ) and quantification (10σ) limits for the preconcentration of 10 mL of sample solution were 0.09 µg L^{− 1} and 0.2 µg L^{− 1} respectively. The precision, expressed as the relative standard deviation (RSD), for 10 replicate determinations at 5.0 µg L^{− 1} Pb level was 6.0%. Verification of the accuracy was carried out by analysis of two certified reference materials (NIST SRM 1640e and VKI QC Metal LL1). The method was successfully applied to the determination of Pb in drinking water samples.     

锂铅合金释氚实验研究

由于锂铅合金因具有高增殖比、低活泼性和可能作为冷却剂的特点,被认为是最有潜力的能源堆包层氚增殖材料。在理论模型描述熔融锂铅合金氚释放行为的基础上,开展了中子辐照后Li₁₇Pb₈₃合金的离线氚释放实验。结果表明: 释放氚的化学形式99％以上为难溶于水的成分（HT或T2）; 氚滞留时间随载气中氢分压的增加而减小,氢分压达到1000 Pa后变为常数,且与实体积无关;氚释放速率对温度的依赖性符合Arrhenius定律。以此为基础得到的氚在熔融锂铅中的动力学参数结果,虽与文献值有差异,但同样证明了在633—973 K的范围内, 氚从液态锂铅到气相的整个释放过程中起决定作用的是氚在合金内的扩散和气\|液界面的多相反应重组。Lithium\|lead alloy is considered to be one of the most prominent tritium breeding materials for the fusion reactor blanket because of its high breeding ratio, and low reactivity and possible use as coolant. An out\|of\|pile experiment of tritium release from Li₁₇Pb₈₃ alloy was performed after neutron irradiation on the base of mathematical model to describe tritium release behavior from an eutectic lithium\|lead alloy. The results suggest that the dominant chemical form of the released tritium (>99%) was the water\| insoluble component (HT or T2). Tritium residence time decreased with increasing H₂pressure in carrier gas up to 1000 Pa, and above this concentration limit it became constant and not influenced by the plenum volume. The temperature dependence of the tritium release rate can be described by an Arrhenius law. Consequently, the present results on the kinetic parameters of tritium in molten Li₁₇Pb₈₃alloy are considered to be different from the values in literature, but it is the same that the overall release process is governed by the diffusion of tritium atoms in the Li₁₇Pb₈₃and by the heterogeneous reaction at the gas\|eutectic interface of the tritium atom recombination at temperatures from 633 to 973 K.     

肾病综合症、过敏性紫癜患儿血清原中铅含量研究

采用原子吸收光谱法，测定了肾病综合症、过敏性紫癜患儿血清和尿中铅含量，均高于近期国内外报道允许正常值，给临床治疗和诊断提供了一个新的研究途径。     

ICP-AES法测定淀粉中的铅、汞、镉、砷

建立了ICP-AES法测定淀粉中铅、汞、镉、砷的方法。用HNO3、HClO4处理样品,然后用ICP-AES法进行测定。加标回收率为98．2％～104．3％,测定结果的相对标准偏差均小于5％(n=5)。     

密闭高压消解–ICP–AES测定进口铜精矿中铅、镉、汞、砷

采用密闭高压消解法对样品进行消解,用电感耦合等离子体发射光谱法(ICP–AES)测定进口铜精矿中的铅、镉、砷、汞有害元素。铅、镉、砷、汞的工作曲线分别在0~10,0~1,0~4,0~0.6μg/mL范围内线性良好,线性相关系数大于0.999。各元素加标回收率均为91.0%~104.7%,相对标准偏差均小于3%(n=7)。将密闭高压消解法与电热板加热法和微波消解法进行了比对分析,结果显示,密闭高压消解–ICP–AES法适合用于铜精矿样品的消解与测定。     

Green synthesis and characterization of Tb-Fe-O-Cu ceramic nanocomposite and its application in simultaneous electrochemical sensing of zinc,cadmium and lead

In this work, a green technique for preparing TbFeO₃/CuO was reported by employing Crataegus and Lantana Camara leaves as fuel and alkalizing agents, respectively. The new sensor based on the perovskite-type nanocomposite was employed as a sensitive and selective platform to detect Pb(II), Zn(II) and Cd(II) simultaneously. TbFeO₃/CuO/Carbon paste electrode (CPE) exhibited a large specific surface area and great electrical conductivity, which enhanced electron transport in the electrochemical process considerably. Moreover, square wave anodic stripping voltammetry (SWASV) was used for the investigation of some factors influencing the sensor sensitivity like pH, modifier concentration, as well as accumulation time and potential. Therefore, the low detection limit (LOD) and a wide linear range were obtained at optimum conditions. In this study, a linear range between 0.9 and 110 µg/L for three ions and LOD of 0.48, 0.29 and 0.12 for zinc, cadmium and lead were achieved, respectively. Moreover, TbFeO₃/CuO/CPE was employed to detect zinc, cadmium and lead ions simultaneously in the real samples so that the results have shown consistency with a standard inductively coupled plasma (ICP).     

极谱分析法连续测定痕量铅和镉

研究了 Pb2 + 和 Cd2 + 与 KCl-酒石酸钠 -三乙醇胺 -明胶体系的二次导数极谱波。在 p H=4 .5的 HAc-Na Ac介质中 ,Pb2 + 和 Cd2 + 分别于 - 0 .4 6 V和 - 0 .6 4V电位处产生一良好的极谱波。峰电流与 Pb2 + 和Cd2 + 的浓度分别在 1× 10 -5— 3× 10 -1g· L-1和 5× 10 -5— 6× 10 -3 g· L-1范围内呈线性关系。 Pb2 + 和Cd2 +的检出限分别为 1× 10 -7g·L-1和 5× 10 -7g·L-1。本法准确、简便、快速、选择性高。已直接用于饮料中铅和镉的连续测定 ,同时也对酒及面粉样品进行了测定 ,回收率分别为 99.9%— 10 0 .1%和 97.0 %—10 4 .8%。     

Luminescence and relaxed excited state origin in CsI:Pb crystals

Emission and excitation spectra, luminescence polarization and decay kinetics have been studied for CsI:Pb crystals in the 0.36-300 K temperature range. The origin of the excited states responsible for the optical characteristics has been discussed. It has been concluded that the doublet ≈3.70 eV absorption (excitation) band is caused by the electronic transitions into the Pb²⁺ triplet state split due to the presence of a cation vacancy near a Pb²⁺ ion, while the higher-energy bands are of the charge-transfer origin. Like in CsI:Tl, four emission bands of CsI:Pb have been found to belong to the main luminescence centres. Two emission bands, peaking at 3.1 and 2.6 eV, are suggested to arise from the triplet relaxed excited state of a Pb²⁺ ion. Two visible emission bands, peaking at 2.58 and 2.23 eV, are interpreted as the luminescence of an exciton localized near the Pb²⁺ ion.