聚（丙烯酰胺—丙烯酸）／聚（丙烯酰胺—二甲基二烯丙基氯化铵）聚电解质复…

通过动态光散射、粘度和透光率测定，研究了聚（丙烯酰胺－丙烯酸）［Ｐ（ＡＭ－ＡＡ）］／聚（丙烯酰胺－二甲基二烯丙基氯化铵）［Ｐ（ＡＭ－ＤＭＤＡＡＣ）］聚电解质复合溶液的结构和性能。结果表明，Ｐ（ＡＭ－ＡＡ）与Ｐ（ＡＭ－ＤＭＤＡＡＣ）复合比、溶液浓度和氯化钠用量影响溶液中复合物的构象和流体力学半径。Ｐ（ＡＭ－ＡＡ）与Ｐ（ＡＭ－ＤＭＤＡＡＣ）分子链间适度的库仑相互作用，可形成均相Ｐ（ＡＭ－ＡＡ）／Ｐ（Ａ     

交联壳聚糖在锑形态分析中的应用

研究了交联壳聚糖（ＣＣＴＳ）对Ｓｂ（Ⅲ）－吡咯烷二硫代氨基甲酸铵（ＡＰＤＣ）和Ｓｂ（Ⅴ）－ＡＰＤＣ的吸附行为，并探讨了吸附机理。结果表明：在ｐＨ＝２时Ｓｂ（Ⅲ）－ＡＰＤＣ和Ｓｂ（Ⅴ）－ＡＰＤＣ的吸附率分别为９６％和９８％。吸附后，利用Ｓｂ（Ⅲ）和Ｓｂ（Ⅴ）形成氢化物的不同条件分别测定，建立了氢化物发生原子吸收（ＨＧＡＡＳ）测定水中痕量Ｓｂ（Ⅲ）和Ｓｂ（Ⅴ）的方法。该法的检出限为６０ｎｇ／Ｌ，回收率为９５％～１０７％，相对标准偏差为２１％～５６％。     

导电高聚物聚2，5－二甲基苯胺的化学合成与特性

报道了聚２，５－二甲基苯胺（ＰＤＭｅＡｎ）的化学合成，并用标准四探针方法测定其电导率，以ＦＴＩＲ、ＵＶ－Ｖｉｓ吸收光谱、元素分析和ＣＶ法对其性质进行了研究，ＰＤＭｅＡｎ的结构与聚苯胺和聚２，５－二甲氧基苯胺的结构类似，是由其单元通过氮原子（Ｎ）在对位上键合而成，本征态的ＰＤＭｅＡｎ能溶于多种有机溶剂，如ＣＨ２Ｃｌ２、ＣＨＣｌ３、ＤＭＳＯ、ＤＭＦ等。     

4-(2-吡啶偶氮)间苯二酚显色-分光光度法测定无机铅和烷基铅

１引言铅是公路两侧大气监测中重点控制的重金属元素。不同形态铅的毒性差异很大，其中三烷基铅的毒性最大。我国目前尚无大气中烷基铅的监测方法，用分光光度法进行铅形态分析也未见报道。本文报道了４－（２－吡啶偶氮）间苯二酚（ＰＡＲ）显色－分光光度法测定无机铅、二乙基铅和三乙基铅的方法，有较好的回收率和精密度，可用于测定大气飘尘中的烷基铅。二实验部分２．１仪器及试剂７２２型分光光度计，ｐＨＤ－１１型数字式酸度计。０．２４０ｍｍｏｌ／Ｌ二乙基铅（ＰｂＥｔ２）、三乙基铅（ＰｂＥｔ３）和０．４８０ｍｍｏｌ／Ｌ无机…     

脱氧核糖核酸变性和损伤的吸附伏安法研究

本文用汞电极（ＨＭＤＥ）二次导数阴极吸附伏安（ＳＤ－ＡｄＣＳＶ）和碳电极（ＧＣＥ、ＣＰＥ）导数循环伏安（ＦＤ－ＣＶ）法研究了核酸受热、紫外线、超声波和丝裂霉素Ｃ（ＭＭＣ）作用下的变性作用。在０．１ｍｏｌ／Ｌ（Ｋ２ＨＰＯ４＋ＫＨ２ＰＯ４）－０．１ｍｏｌ．Ｌ ＮａＣｌ（ｐＨ７．０）底液中，吸附的单股（ｓｓ－）和双螺旋（ｄｓ－）ＤＮＡ分别在ＨＭＤＥ上得到特征还原峰Ｐ３和Ｐ２，和在碳电极上得到氧化峰Ａ。物     

偶合标记铜离子催化放大的极谱免疫分析法测定破伤风类毒素

建立了测定破伤风类毒素的铜离子标记极谱免疫分析方法．用二乙三胺五乙酸（ＤＴＰＡ）酸酐法将用离子标记于抗原破伤风类毒素（ＴＴ）．所得标记物中ＴＴ：ＤＴＰＡ：Ｃｕ的摩尔标记比为 １：６：６、铜离子催化底ｏ－苯二胺（ＯＰＤ）的氧化反应，生成电活性产物 ２，３－二氧基吩嗪（ＤＡＰ），以单扫描极谱法检测ＤＡＰ．采用异相竞争免疫分析模式，本方法可测定０．０５～１ｍｇ／Ｌ ＴＴ。     

紫外分光光度-CPA矩阵法同时测定2-(2′-呋喃基)苯并咪唑和邻苯二胺

研究了２－（２′－呋喃基）苯并咪唑（ＦＢＤ）和邻苯二胺（ＯＰＡ）在无水乙醇溶液中的紫外吸收光谱，建立了多波长同时测定ＦＢＤ和ＯＰＡ的紫外光度ＣＰＡ矩阵法。ＦＢＤ和ＯＰＡ分别在０．１～１０ｍｇ／Ｌ和１．０～１００ｍｇ／Ｌ的浓度范围，ＦＢＤ和ＯＰＡ的回收率均大于９３％，相对标准偏差小于７．５％。     

含氮氧功能基新型键合固定相色谱性能及应用研究

用新合成的３－（二乙醇）氨丙基硅氧烷（ＤＥＡＰ）、３－（氮杂１８－冠－６）丙基硅氧烷（ＢＣＰ）作固定相，对二取代苯异构物进行液相色谱分离，研究流动相组成，ｐＨ值及其Ｋ￣＋离子浓度对色谱行为的影响．探讨溶质保留机理，并比较ＤＥＡＰ、ＢＣＰ与ＯＤＳ的色谱性能．     

硝酸钠对几种显色反应作用机理的探讨

本文试验了硝酸钠对Ｍ＾２＋－５－Ｃｌ－ＰＡＤＡＢ、Ｍ＾２＋－３，５－ｄｉＢｒ－ＰＡＤＡＢ、Ｍ＾２＋－５－Ｂｒ－ＤＥ－ＰＡＰ及Ｍ＾２＋－ＰＡＲ（Ｍ＝Ｃｏ、Ｎｉ、Ｃｕ）显色体系的影响，发现硝酸钠对前两种显色体系有较大的影响，而对后两种显色体系的影响甚小。从引入ＮａＮＯ３后吸收光谱的变化，ｐＫａ３的改变，配合物的稳定常数等方面探讨了ＮａＮＯ３对显色反应的作用机理。     

FRS-XRSA表征双轴取向聚对苯二甲酸乙二酯薄膜的取向分布

Ｘ－射线散射理论分析（ＦＲＳ－ＸＲＳＡ）是作者为了研究和表征取向高聚物结晶度与晶粒取向分布（ＯＤＣ）的一种新方案．在表征ＯＤＣ方面应用分峰法（ＣＰＲ）消除了传统极图法（ＰＦＭ）中高重叠峰相互干扰的困难，克服了取向分布函数分析（ＯＤＦＡ）中出现虚织构的困难，并且经一次系统的ＦＲＳ－ＸＲＳ测定，可以得到几乎所有主要（ｈｋｌ）晶面法向的ＯＤＣ．作者应用ＦＲＳ－ＸＲＳＡ对二类双轴取向ＰＥＴ磁带薄膜进行了ＯＤＣ的研究。基于结晶几何学原理（ＣＧＰ），建立了三斜晶系晶粒坐标系与试样坐标系的关系，并用于推演未测定方位角（αｉ，βｉ）（ｈｋｌ）的晶面散射以及未测（ｈ′ｋ′ｌ′）晶面的ＯＤＣ．作者关系建立了双轴取向函数〈ｃｏｓ２φｈｋｌ，ｉ〉，ｉ＝Ｎ、Ｍ、Ｔ的计算公式．按照ＦＲＳ－ＸＲＳＡ获得了反映取向分布的１０个晶面的双轴极图、三个主晶面（１００）、（０１０）、（１０５）的总极图，以及反映平均取向的各种取向函数，如〈ｃｏｓ２φｈｋｌ，ｉ〉、ｆｃｈｋｌ，ｉ等，结果十分令人满意．     

吡咯烷二硫代甲酸铵螯合纤维素对Cd2+的吸附机理

螯合棉纤维;镉离子;配位吸附;吡咯烷二硫代甲酸铵螯合纤维素对Cd2+的吸附机理     

Spectrophotometric flow-injection determination of nickel in biological materials

A flow injection method has been developed for the direct determination of free available Pb(II) and total Pb content in wine samples. The method is based on the chemical sorption of Pb(II), from pH 7 buffered solutions, on a packed polyurethane foam column, modified by addition of 2-(2-benzothiazolylazo)-p-cresol (BTAC). After this step, lead was directly eluted with a stream of 0.1 mol l(-1) HCl into an air C(2)H(2) flame in which lead was determined by atomic absorption spectrometry. Total lead was analyzed after sample digestion with nitric acid and hydrogen peroxide, being free available lead determined by direct sample on-line preconcentration and elution. The method provides a limit of detection (3sigma) of 1 mug l(-1) lead and relative standard deviation, which varies from 6 to 0.7% for lead concentration of 10 and 500 mug l(-1). Total content of lead in wine samples analyzed varied from 8 to 42 mug l(-1) being obtained free available values of Pb(II) under the limit of detection of the method. Recovery studies on natural wine samples, spicked with inorganic lead, evidenced the remaining capability of ligands, present in the wine, to avoid lead retention on the polyurethane foam loaded with BTAC.     

Differential pulse cathodic stripping adsorption voltammetric determination of trace amounts of lead using factorial design for optimization

A sensitive cathodic stripping voltammetric method is developed for determination of lead(II), with adsorptive collection of complexes with Pyrogallol red (PGR) on to a hanging mercury drop electrode. After accumulation of the complex at −0.80 V vs. Ag/AgCl reference electrode, the potential is scanned in a negative direction from −0.20 to −0.50 V with differential pulse method. Then the reduction peak current for the lead(II)-PGR complex is measured at −0.39 V. The influence of reagent and instrumental variables was completely studied by factorial design analysis. The optimum analytical conditions for the determination of lead(II) were established. Under optimum conditions, lead(II) determined in the range of 0.1-30.0 ng ml⁻¹ with a limit of detection of 0.06 ng ml⁻¹. The method is successfully applied to determination of lead(II) in water sample.     

Application of the radioreagent method for trace determination of lead

A radioreagent method of analysis was developed and applied to the determination of trace quantities of lead in several types of samples. The method is based on the extraction of radioactive cobalt, displaced by lead from the cobalt chelate of ethylenediaminetetraacetate labelled with⁶⁰Co, into a tetracycline-benzyl alcohol solution. The radioactivity of the released cobalt, extracted into the organic phase, is proportional to the lead concentration. Interference caused by some elements was eliminated by means of a previous separation of lead using dithizone. The method was applied for lead determination in aerosol samples, gasoline and samples from the International Atomic Energy Agency, namely: simulated-air filter (Air-3), fresh water (W-3), dried animal whole blood (A-2) and calcined animal bone (A-3/1). The sensitivity, accuracy and precision of the method were also studied.Part of this material was submitted to the University of São Paulo in partial fulfilment for a Doctor of Science's Degree of A. M. G. FIGUEIREDO.     

Determination of lead in blood by hydrodynamic voltammetry in a flow injection system with wall-jet detector

Lead is one of the most widely distributed toxic heavy metals in the environment. It is a cumulative poison, affecting the brain and nervous system. The threshold between the normal lead level and the level where physiological effects become manifest is relatively narrow. It is therefore desirable to screen exposed populations in order to identify the danger in time. The lead concentration in the blood is a measure to the total amount of lead in the body. A fast, accurate and cheap method for the determination of lead in blood is therefore needed. The conventional method used to determine lead in blood is atomic absorption. Electrochemical methods like stripping voltammetry combine high analytical sensitivity with relatively low cost for the equipment; however, electrode preparation is critical for the success of an analysis, and highly skilled personnel are needed. We describe an automated electrochemical method, using flow injection analysis with a wall-jet detector. Lead is released from its binding site in the blood by ion exchange and quantified by stripping voltammetry with a mercury film electrode (MFE). The method allows for the detection of 0.05 ppm Pb(2+) with an accuracy of about 10%. Electrode poisoning by proteins from the blood can be effectively suppressed when a MFE modified with a Nafion(R)-membrane coating is used. Such modified electrodes can be activated in the solution without further treatment, and used for more than 100 analyses before they have to be replaced. A solid matrix MFE with a Nafion(R)-membrane and all necessary chemicals for mercury film formation and lead release has been developed. Such electrodes are discussed as disposable electrodes for a portable blood lead detector.     

Determination of Lead by Electrochemistry

Lead is one of the poisonous trace element for human body. It is important to find a way for measuring content of lead. Deternination of lead by electrochemistry is one of a method[1]. In this paper, lead is determined by single-sweep polarography. The absorption behavior of meso-tetra (4-sulfonylphenyl) porphyrin (H2TPPS4) complex with lead ion has also been studied.In Na2B4O7-NaOH solution with pH=l 0.5, the reduction peaks of the ligand are P1 (Ep1=-0.38V), P2 (Ep2=-1.04V), which potentials are obtained vs. S.C.E. When lead ion has been added into above solution. The peak current of P1 and P2 decrease, and a new reduction peak P3 (Ep3=-1.10 V) appears. It shows that the TPPS4-Pb(Ⅱ) complex forms,and this method can be applied to study the complex.     

Determination of metals in urine by direct injection of sample,high-performanc liquid chromatography and electrochemical or spectrophotometric detection

A method for the rapid and simultaneous determination of copper, nickel and lead in urine is described. Direct injections of freshly acidified and filtered (0.45-μm) urine samples were made onto a reverse-phase separator column with a guard column for sample clean-up. By complexing the metals with a dithiocarbamate ligand included in the mobile phase, the metal complexes could be detected electrochemically (copper and nickel) or spectrophotometrically (copper, nickel and lead). The procedure is shown to provide a convenient method for the determination of copper and nickel at normal to occupationally exposed levels of urinary output (electrochemical detection) after direct injection of samples. Spectrophotometric detection methods were insufficiently sensitive for direct determinations of copper and nickel at some of the lower levels found in urine. The spectrophotometric detection of lead is subject to interference by u.v.-absorbing constituents present in urine and is restricted to detection of lead in persons over-exposed to lead, unless additional clean-up procedures are applied.     

Spectrophotometric Label-Free Determination of Lead Using Thiol-Functionalized Gold Nanoparticles

A method for the determination of lead is described using thiol-functionalized gold nanoparticle. The detection method is based on the prevention of thiol-induced aggregation of gold nanoparticles by lead. Among six thiols, e.g., 4-mercapto-1-butanol, meso-2, 3-dimercaptosuccinic acid, mercaptosuccinic acid, 6-mercapto-1-hexanol, 4-(methylthio)-1-butanol, 1-propanethiol, four (4-mercapto-1-butanol, 6-mercapto-1-hexanol, 4-(methylthio)-1-butanol and 1-propanethiol) induced the aggregation of the gold nanoparticles which was measured by the change in absorbance at 520 and 650?nm. Prior incubation of the gold nanoparticles with lead decreased the 4-(methylthio)-1-butanol-induced aggregation of gold nanoparticles in a dose-dependent manner. A linear inverse relationship between the logarithmic concentration of lead and the ratio of absorbance at 650 to 520 was noted. The method has a dynamic range from 10?nM to 100?µM. However, metals such as mercury and chromium were more effective in comparison with lead in preventing the 4-methylthio-1-butanol-induced aggregation of gold nanoparticles. The method can be used for assessing the heavy metal load in water samples.     

Application of a new nanoporous sorbent for extraction and pre-concentration of lead and copper ions

The authors describe a method for the trace determination of copper (II) and lead (II) in water and fish samples using solid-phase extraction via siliceous mesocellular foam functionalised by dithizone. Siliceous mesocellular was functionalised with dithizone, and the resulting sorbent was characterised by scanning electron microscopy, surface area analysis, thermogravimetric/differential thermal analysis and FTIR. Following solid-phase extraction of target ions by the sorbent, copper and lead ions were quantified by flame atomic absorption spectrometry. Factors affecting the sorption and desorption of target ions by the sorbent were evaluated and optimised. The calibration plot is linear in the 1 – 500 μg L^?1 copper (II) and 3–700 μg L^?1 lead (II) concentration range. The relative recovery efficiency in real sample analysis is in the range from 96 to 102%, and precision varies between 1.7 and 2.8%. It is should be noted that the limits of detection for the copper and lead analysis were 0.8 and 1.6 μg L^?1, respectively. Also, the adsorption capacities for copper and lead ions were 120 and 160 mg g^?1, respectively. The obtained pre-concentration factor for the lead and copper ions by the proposed solid-phase extraction was 75. The method was successfully applied to the determination of low levels of copper (II) and lead (II) in tap, Caspian sea, Persian gulf and lake water and also their detection in fish samples.     

Determination of cadmium and lead at μg/1 levels in aqueous matrices by chelation ion chromatography

A method for the simultaneous determination of μg/1 or sub-μg/1 levels of cadmium and lead in sea water by chelation ion chromatography is demonstrated. The method consists in the preconcentration of a sea-water sample containing cadmium and lead on an iminodiacetate chelating resin; alkali and alkaline earth metals are removed from the resin with an ammonium acetate buffer, the metals are eluted and separated by cation-exchange chromatography, followed by postcolumn derivatization with 4-(2-pyridylazo)resorcinol and spectrophotometric detection at 520 nm. The concentration and separation steps are automated. The detection limit, when concentrating 200 ml of sea water, was found to be 2 ng for cadmium and 6 ng for lead. Relative standard deviations of 4.5% and 6.8% for 10 μg/1 of cadmium and lead, respectively, were obtained. Transition metals (Fe, Co, Ni, Zn, Cu, Mn) do not interfere in the analysis. An application of the method to the determination of cadmium and lead in sea-water samples collected in the Taranto gulf (Italy) is presented.