含铅聚合物微凝胶与硫化氢反应前后在良溶剂中的分子扩散行为

用溶液聚合法制备出轻度交联的含铅微凝胶,用光子相关光谱技术测定其在良溶剂中与H2S反应前、后的扩散行为,由外推法得到在浓度无限稀时的分子扩散系数,给出微凝胶的流体力学半径。结果表明:相同量的含铅微凝胶在不同的初始浓度下与H2S反应,生成含PbS纳米微粒的凝胶；但其体积增大不同,这说明H2S与含铅微凝胶的反应既可以在分子内也可以在分子间进行,分子间的反应使含硫化铅微凝胶扩散系数随浓度的变化曲线的线性范围变小。     

CL-7402萃淋树脂分离富集铅的研究及其应用

通过静态和动态实验,研究了CL-7402萃淋树脂吸附铅的性能和减压微色谱柱分离富集铅的最佳条件。实验表明,此萃淋树脂吸附快,吸附容量大。在减压条件下,以1mol/LHBr为上柱介质,2mol/LHNO3为洗脱液,可使铅与铜、铁等金属离子快速分离。采用三溴偶氮胂光度法测定样品中的铅。     

土壤环境中铅的化学

论述了环境中铅的背景值、来源、污染、质量标准、化学循环以及环境中铅的烷基化，为铅污染治理提供理论依据。     

Anti-solvent assisted treatment for improved morphology and efficiency of lead acetate derived perovskite solar cells

An efficient solution-processable route employing Pb(Ac)₂ as lead source and anti-solvent treatment to achieve fully covered and homogenous perovskite films is reported.     

氢化物发生—分光光度法测定染发剂中的微量铅

本文提出了用铁氰化钾将铅氧化至高价,再用氢化物发生-分光光度法测定铅的一种新方法。该法灵敏度高,简便快速,用于分析染发剂中的铅,取得了较好的效果。     

Organic fuelled flames in selective ionization detectors for chromatography

Summary The selectivities of two flame-based ionization detectors identified as a Remote FID (RFID) and a Flame Thermionic Ionization Detector (FTID) have been improved by introducing methane as a fuel for the flame. Both the RFID and FTID feature a detector struture in which the ionization polarizer and collector are located several centimeters downstream of an oxygen-rich flame, rather than immediately adjacent to the flame as in a flame ionization detector. The RFID detects long-lived negative ions produced in the flame by the combustion of lead, tin, phosphorus, or silicon compounds. The FTID re-ionizes and detects neutral electronegative products generated by combustion of nitrogen, halogen, or phosphorus compounds. An organic-fuelled RFID can detect 1 pg Pb (Sn, P)/sec with a selectivity of the order of 10⁶ versus hydrocarbons. An organic fuelled FTID is applicable to detection of compounds at nanogram and higher levels. FTID selectivity for PCB compounds in a transformer oil matrix is of the order of 10⁵1. The improved selectivity achieved by using an organic-fuelled flame is also applicable to the detection of phospholipid and other non-volatile N, P, or Cl compounds using an FID/FTID detector accessory for a TLC/FID analyser.     

Characteristics of Subtractive Anodic Stripping Voltammetry of Lead,Cadmium and Thallium at Silver‐Gold Alloy Electrodes

Silver‐gold alloy electrodes have been studied for the purpose of the quantitative determination of heavy metals by subtractive anodic stripping voltammetry, (SASV). The results have been compared with those obtained with the silver and gold electrodes. The 50/50 a/o Ag/Au alloy electrode is the most suitable for quantifying thallium in the presence of lead and cadmium. The separation of its peak from those of lead and cadmium is 200 mV, which is about twice the separation obtained on the pure metal electrodes and is also better than on mercury. The silver electrode is suitable for the simultaneous determination of thallium, lead and cadmium. The peaks of lead and cadmium overlap on the 50/50 alloy. Pure silver or pure gold can be used for simultaneous quantification of these two metals. The use of gold for quantifying lead and cadmium is more limited because the peak potential of cadmium is shifted in the negative direction as its concentration increases and at [Cd²⁺]>200 nM, the two peaks merge. SASV enables correction for background currents and is of utmost importance for obtaining well‐defined peaks. The peaks of lead, cadmium and thallium appear over a relatively narrow potential range (ca. 200 mV) on all the electrodes presented in this work. For this reason, the quantifying of a peak is based on the derivative at the inflection point of only one of its branches (ascending or descending). All SASV measurements were carried out without removal of oxygen.     

Pb2(OH)2[p‐O2C‐C6H4‐CO2]: Synthese und Kristallstruktur

Pb₂(OH)₂[p‐O₂C‐C₆H₄‐CO₂]: Synthesis and Crystal Structure Single crystals of Pb₂(OH)₂[p‐O₂C‐C₆H₄‐CO₂] ( 1 ) were obtained by hydrothermal reaction of terephthalic acid and PbCO₃ at 180 °C (10 days). 1 crystallizes in the monoclinic space group P2₁/c with Z = 2 (a = 1115.6(2) pm, b = 380.10(4) pm, c = 1141.3(2) pm, β = 93.39(1)°, V = 0.4831(1) nm³). The crystal structure is characterized by ladder‐type Pb(OH)_3/3 double chains, which are connected to a three‐dimensional framework by terephthalate dianions.     

Synthesis of PbTiO3 ceramics using mechanical alloying and solid state sintering

The pressure-less sintering behavior of PbTiO₃ powders synthesized by mechanical alloying TiO₂ and PbO was investigated using dilatometry and Rietveld refinements of X-ray diffraction patterns. As-synthesized, the powders are nanocrystalline with a mean particle size of 20 nm. Pressure-less sintering in the range 500-1050°C gives single phase ceramics with densities of 85-90% and crystallite sizes in the range 80-400 nm. Cracking due to the paraelectric-ferroelectric phase transition was not observed in samples sintered below 700°C due to the small crystallite size whereas macroscopic cracks formed in samples sintered above 700°C. Rietveld analysis indicates the formation of Pb vacancies in samples sintered and held for 24 h at intermediate temperatures (600-1000°C) which gives some insight into the mechanism of Pb loss and second phase formation in this system.     

A sensitive spectrophotometric method for lead determination by flow injection analysis with on-line preconcentration

A new flow injection (FI) system for the determination of Pb(II) at trace level with a preconcentration step and spectrophotometric detection is proposed. It is based on preconcentration of lead ions on chitosan and dithizone-lead complex formation in aqueous medium (pH 9). The chemicals and FIA variables influencing the performance of the system were optimized and applied to the determination of lead in natural, well, and drinking water samples. It is a simple, highly sensitive, and low cost alternative methodology. The method provided a linear rage between 25 and 250 μg l⁻¹, a detection limit of 5.0 ng ml⁻¹ and a sample throughput of 15 h⁻¹. The obtained results of spiked samples are in good agreement between the proposed method and ICP-AES.