基于铜纳米簇的聚集诱导发光检测铅离子

基于谷胱甘肽保护的非贵金属铜纳米簇(Cu NCs@GSH)的聚集诱导发光现象,建立了快速检测铅离子(Pb2+)的“Turn on”型荧光分析方法.Cu NCs@GSH溶液荧光强度很弱,当存在pb2+时,荧光强度可显著增强,溶液显示明亮的橙黄色.基于此原理建立了检测pb2+的荧光方法,线性范围为200～700 μmol/L,检出限为106 μmol/L,常见金属离子不干扰pb2+的测定.本方法简单快速、选择性高,可实现对pb2+的可视化定性检测.     

动态三磁场塞曼背景校正技术应用于石墨炉原子吸收光谱法测定血样中铅

在石墨炉原子吸收光谱法测定血样中铅时,采用动态三磁场塞曼背景校正技术,使血样中铅测定的线性范围由0～100μg.L-1扩增到0～800μg.L-1。动态模式下,质量浓度在80μg.L-1范围以内选择二磁场背景校正模式,特征量为29.4pg。在80～800μg.L-1范围内选择三磁场背景校正模式,特征量为10.7pg。应用此法测定高浓度铅的样品时无需稀释,同时解决了高浓度样品测定时出现塞曼反转,及吸收信号出现双峰的问题。     

Individual and simultaneous determination of lead, cadmium, and zinc by anodic stripping voltammetry at a bismuth bulk electrode

A bismuth bulk electrode (BiBE) has been investigated as an alternative electrode for the anodic stripping voltammetric (ASV) analysis of Pb(II), Cd(II), and Zn(II). The BiBE, which is fabricated in-house, shows results comparable to those of similar analyses at other Bi-based electrodes. Metal accumulation is achieved by holding the electrode potential at −1.4 V (vs. Ag/AgCl) for 180 s followed by a square wave voltammetric stripping scan from −1.4 to −0.35 V. Calibration plots are obtained for all three metals, individually and simultaneously, in the10-100 μg L⁻¹ range, with a detection limit of 93, 54, and 396 ng L⁻¹ for Pb(II), Cd(II), Zn(II), respectively. A slight reduction in slope is observed for Cd(II) and Pb(II) when the three metals are calibrated simultaneously vs. individually. Comparing the sensitivities of the metals when calibrated individually vs. in a mixture reveals that Zn(II) is not affected by stripping in a mixture. However, Pb(II) and Cd(II) have decreasing sensitivities in a mixture. The optimized method has been successfully used to test contaminated river water by standard addition. The results demonstrate the ability of the BiBE as an alternative electrode material in heavy metal analysis.     

Simultaneous Determination of Cadmium,Lead, Copper and Mercury Ions Using Organofunctionalized SBA‐15 Nanostructured Silica Modified Graphite–Polyurethane Composite Electrode

A new sensor has been developed for the simultaneous detection of cadmium, lead, copper and mercury, using differential pulse and square wave anodic stripping voltammetry (DPASV and SWASV) at a graphite–polyurethane composite electrode with SBA‐15 silica organofunctionalized with 2‐benzothiazolethiol as bulk modifier. The heavy metal ions were preconcentrated on the surface of the modified electrode at ?1.1 V vs. SCE where they complex with 2‐benzothiazolethiol and are reduced to the metals, and are then reoxidized. Optimum SWASV conditions lead to nanomolar detection limits and simultaneous determination of Cd²⁺, Pb²⁺, Cu²⁺ and Hg²⁺ in natural waters was achieved.     

Synthesis,Crystal Structure,and Characterization of a New Metal Borophosphate: PbII4{Co2[B(OH)2P2O8](PO4)2}Cl

A new metal borophosphate Pb^II₄{Co₂[B(OH)₂P₂O₈](PO₄)₂}Cl ( 1 ), containing both Pb²⁺ cations and Cl^– anions, was hydrothermally synthesized and characterized by powder X‐ray diffraction, ICP, TG/DTA, and FTIR spectroscopic analyses. The crystal structure determination from single‐crystal X‐ray diffraction reveals that compound 1 crystallizes in the trigonal space group R c (No. 167), a = 9.7513(7) Å, c = 91.060(13) Å, V = 7498.7(13) Å³ and Z = 18. Its structure features a new cobalt borophosphate layer {Co₂[B(OH)₂P₂O₈](PO₄)₂}^7– built up from CoO₅ square pyramids, [B(OH)₂P₂O₈]^5– borophosphate trimers and PO₄ tetrahedra. Extra‐framework Pb²⁺ and Cl^– ions are located at the vacancy of layers to achieve the charge neutrality of the framework. Magnetic measurements indicate that antiferromagnetic interactions exist between Co²⁺ ions with a negative Weiss constant of –20.3 K.     

Determination of Hg and Pb in compact fluorescent lamp by slurry sampling inductively coupled plasma optical emission spectrometry

Mercury and lead were determined in an extraction solution applied to compact fluorescent lamps by axial view inductively coupled plasma optical emission spectrometry (ICP OES). The solution contained 50% v/v HNO₃ and 10% v/v H₂O₂. The compact fluorescent lamps were treated by removing the socket and breaking the rest of the lamp inside the solution, followed by placing the mixture in an ultrasonic bath for 1 h. The mixture was filtrated in a coarse paper filter and the resulting extraction slurry was analyzed. The determination of Pb in the slurry required calibration by the analyte addition technique, while for Hg, external calibration was adequate. The quantification limits (10 s, n = 7), for Hg (194.164 nm) and Pb (220.353 nm) were, respectively, 10 and 30 µg per lamp. Analysis of spiked samples demonstrated reasonable accuracy of the method, with recoveries in the range from 99 to 120% for Hg and from 91 to 107% for Pb. Fifteen analyzed samples showed Hg masses per lamp in the range from 1.6 to 27 mg, and six samples were above the limit allowed by the European Community that is 5 mg per compact lamp. The values for Pb were between 0.07 and 0.75 mg per lamp. By filtrating the slurry in a membrane filter, and analyzing the resulting solution, it was found that all Hg was extracted to the liquid phase of the slurry, while a fraction of about 40% m/v of Pb is retained in the solid particles. The lamp cover glass, after extraction of the phosphor layer, was also analyzed for Hg and Pb. The concentration of Hg in the glass is quite low; however, the Pb content is high.     

Lead-sensitive membrane electrode based on chelating ion exchanger

A new selective membrane electrode for the measurement of lead activities is proposed. The preparation of active components of the membrane is described. The ready made electrode insert was used in which the PVC membrane was replaced by the prepared membrane. Experimental results document the emf response of profile, the selectivity, the detection limit and the effect of the sample media. The prepared electrode was applied for the measurement of the lead concentration in water samples. Activated alumina micro-column was used for the pre-concentration of lead in the analyzed water samples. The obtained results were compared with those determined by atomic absorption spectrometry.     

Sensitive and Simple Electrochemical Detection of Lead(II) with Carbon Ionic Liquid Electrode

In this paper a carbon ionic liquid electrode (CILE) was fabricated by using ionic liquid 1‐ethyl‐3‐methylimidazolium ethylsulphate ([EMIM]EtOSO₃) as the modifier and further used as the working electrode for the sensitive anodic stripping voltammetric detection of Pb²⁺. The characteristics of the CILE were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In pH 4.5 NaAc‐HAc buffer Pb²⁺ was accumulated on the surface of CILE due to the extraction effect of IL and reduced at a negative potential (‐1.20 V). Then the reduced Pb was oxidized by differential pulse anodic stripping voltammetry with an obvious stripping peak appeared at ?0.67 V. Under the optimal conditions Pb²⁺ could be detected in the concentration range from 1.0 × 10^?8 mol/L to 1.0 × 10^?6 mol/L with the linear regression equation as I_p(μA) = ?0.103 C (μmol/L) + 0.0376 (γ = 0.999) and the detection limit as 3.0 × l0^?9 mol/L (3σ). Interferences from other metal ions were investigated and Cd²⁺ could be simultaneously detected in the mixture solution. The proposed method was further applied to the trace levels of Pb²⁺ detection in water samples with satisfactory results.     

激光烧蚀-电感耦合等离子体质谱法测定塑料中的Pb、Cd、Cr和Hg

采用激光烧蚀固体进样技术的电感耦合等离子体质谱法(LA-ICP-MS)测定了塑料中的Pb、Cd、Cr和Hg。选择了线扫描激光烧蚀方式,并从灵敏度和稳定性角度优化了工作参数。根据计算分馏因子考察了分馏效应,结果表明,所测元素分馏效应小。塑料中Hg的记忆效应严重,认为主要来自样品表面吸附,减小样品的表面积可减小Hg的记忆效应。以聚丙烯标准物质及其空白片作校准曲线,应用于ABS、PPS、PA66+30%GF、PVC、PTFE等实际塑料样品的测定,测定结果与ICP-OES(XRF)法测定值基本吻合。Pb、Cd、Cr和Hg的检测下限分别为0.002、0.001、0.08和1.5 mg/kg。     

应用ICP-MS和GFAAS测定藻类食品中铅、镉的方法研究及比较

建立微波消解-电感耦合等离子体-质谱法(ICP-MS)测定藻类食品中铅、镉含量的方法,并与国家标准方法石墨炉原子吸收光谱法(GFAAS)进行了比较.样品经过微波消解,分别使用ICP-MS和GFAAS测定藻类食品裙带菜和海带中铅、镉含量,各元素校正曲线的相关系数均大于0.9991,样品分析结果RSD均小于3.6%(n=6...