钨丝在原子吸收光谱分析中的应用

随着原子化器和检测器的小型化，钨丝原子吸收光谱分析仪在便携式分析仪器方面显示了很大的潜力。本文主要评述了近年来钨丝在电热原子吸收光谱分析中的应用，引用文献49篇。     

电沉积-钨丝电热原子吸收光谱法测定水样中的铅

研制了一种便携式钨丝电热原子吸收光谱分析装置,其主要包括:钨丝电热原子化器、多道微型CCD光谱仪、仪器电源系统以及控制系统。并将电沉积分离富集技术与该钨丝电热原子吸收光谱分析仪器结合,完成环境水样中铅的现场分析。并对铅的电沉积条件作了研究,最佳电沉积电位为负650 mV(vs.SCE),方法检出限:0.20μg/L,线性范围:1~15μg/L,对4μg/L Pb标准溶液10次重复测试,RSD为4.4%。     

电沉积-钨丝电热原子吸收光谱法测定地质样品中痕量金

以市售幻灯投仪卤钨灯泡钨丝为原子化器的钨丝电热原子吸收光谱分析仪(TC-AAS),功率小、仪器成本低[1,2],如用微型CCD光谱仪作检测系统,可以实现原子吸收光谱仪的小型化,甚至可用于野外现场分析[3,4].     

钨丝电热原子吸收光谱分析法测定痕量锌

蒸馏水中的锌与吡咯烷二硫代氨基甲酸铵(APDC)形成的络合物用CCl4萃取后,弃去有机相,水相用作配制锌标准溶液和制备样品溶液,从而解决了用钨丝电热原子吸收光谱法测锌时空白值太高而难以进行实际样品分析的问题.考察了影响萃取和钨丝电热原子吸收测定的各种实验条件.在进样10 μL样品溶液时,本方法的定量下限为5 μg/L.测定了3个国家标准物质(大米、人发和水系沉积物)中的锌含量,结果与推荐值一致.     

钨丝电热蒸发-氩/氢火焰原子吸收光谱分析方法

基于钨丝电热蒸发设备,建立了一种全新的钨丝电热蒸发-氩/氢火焰串联原子吸收光谱系统.研究了系统抗酸、抗盐能力,结果表明:Na<'+>和Ca<'2+>质量浓度小于400 mg/L、Mg<'2+>质量浓度小于1500 mg/L时不干扰测定.在优化的仪器条件下:Pb、Cd、Au和Ag的检出限分别为:0.016、0.0005、...     

便携式钨丝电热原子吸收光谱仪测定水样中铜、铬、铅和镉

以钨丝原子化器和小型化CCD检测器为主要部件,组装了便携式钨丝电热原子吸收光谱分析仪,优化了载气(Ar/H2) 流速、空心阴极灯位置、原子化器高度、灰化和原子化电流等主要仪器条件.最佳载气(Ar/H2)流速(mL/min)为600 /300(Cd),800/200(Cu, Pb, Cr);灰化电流为2.9～3.2 A;原子化电流为8.5 A;CCD的积分时间为50 ms.并在优化的仪器条件下准确测定了环境水样中的铜(Cu)、铬(Cr)、铅(Pb)和镉(Cd),进样10 μL时,其检出限分别为2、5、9和0.5 μg/L.此便携式原子吸收光谱仪在环境水样痕量元素分析中可望有良好的应用前景.     

壳聚糖富集火焰原子吸收法测定水中痕量铜

采用壳聚糖修饰钨丝基质螺旋卷，直接浸入含有痕量铜的pH5．0的Brltton-Robinson缓冲溶液中，经电磁搅拌富集一定时间后，将其转移至空气／乙炔火焰燃烧器上，利用火焰原子吸收光谱法简便快速测定水中痕量铜。方法的线性范围为2—75μg／L；检出限为0．98μg／L。同一支钨丝螺旋卷重复涂敷壳聚糖富集Cu，RSD(n=6)为2．7％。     

电解预浓缩技术在原子吸收分光光度分析中的应用

本文介绍了电解预浓缩技术的基本装置和各种工作电极材料,重点评述钨丝工作电极在火焰和无火焰原子吸收分析中的应用及其利弊,指出采用电解后的钨丝直接作原子化器可以弥补仪器设备的不足。最后表列出该技术在原子吸收分析中的应用现状。     

钨丝电沉积石墨炉原子吸收光谱法测定食品中不稳定态铅

研究了钨丝电沉积石墨炉原子吸收光谱法测定不稳定态铅的条件。结果表明该方法的灵敏度比常规ＣＦＡＡＳ法提高８０倍，检出限为０．０１μｇ．Ｌ－１；变异系数４．５％，在０－２．５μｇ·Ｌ－１范围内线性关系好，抗干扰强。测定了食品中不稳定态铅。     

电沉积分离富集钨丝电热原子吸收测定微量钯

本文介绍一种电热原子吸收光谱分析测定微量钯的新方法。将溶液中微量钯电还原沉积到钨丝表面,该钨丝再通以一定功率电流使其表面沉积的金属钯蒸发原子化并测量吸光度。确定了各实验参数最佳值,讨论了各种影响因素。电沉积时间(?)秒时,检出限为1.49ng/mL,相对标准偏差为5.18％,钯含量在0-30ng/mL范围内与吸光度呈线(?)关系。方法可用于若矿、催化剂及阳极泥等试样的发析,用管理样进行了分析结果对照,准确度和精密度均较好。     

国内光催化研究进展简述

分1975~1985, 1985~1995和1995~2012三个时期简要介绍了国内光催化研究进展, 主要侧重于光催化材料及其改性、应用和反应机理方面的研究进展, 并指出了当前光催化领域存在的一些重要问题和未来的发展趋势, 涉及到光解水、CO₂还原、环境净化和选择性有机合成等方面.     

青蒿素研究进展

青蒿素是目前治疗疟疾的特效药。本文对自青蒿素发现以来的最新研究进展进行了比较详尽的综述。内容包括: 青蒿素的发现及历史, 青蒿素的来源, 青蒿素的全合成,青蒿素的生物合成, 青蒿素衍生物以及植物组织培养生产青蒿素。     

Recent Advances in Analytical Methodology for in vivo Electrochemistry in Mammals

Electrochemistry is one of the most advanced techniques for monitoring neurochemical activities in the living brain because electrochemical approaches bear the advantageous features of high spatial and temporal resolutions, which facilitate its tremendous potential in investigating the highly spatially heterogeneous brain system and the fast dynamics of neurochemical activities. On the other hand, since brain is the most complicated organ in the sense of its numerous kinds of neurochemical species, high selectivity is always required for any analytical methods that approach the brain. In this review, we will discuss various electrochemical methodologies to achieve selective detection of neurochemicals in mammalian brain and the strategies developed mainly by our group towards selective monitoring of both electrochemically active and inactive neurochemicals. At the end, we will discuss possible solutions towards brain mapping of neurochemical species and combination of neurochemical detection strategy with electrophysiology as the direction of future development of electroanalysis in living brain.     

乙基香兰素研究前景

报导了近几十年来国内外关于乙基香兰素的研究进展与动态,并简单介绍了本文作者在该方面所取得的研究成果,参考文献33篇。     

Reactions in droplets in microfluidic channels

Fundamental and applied research in chemistry and biology benefits from opportunities provided by droplet-based microfluidic systems. These systems enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes. Compartmentalization in droplets provides rapid mixing of reagents, control of the timing of reactions on timescales from milliseconds to months, control of interfacial properties, and the ability to synthesize and transport solid reagents and products. Droplet-based microfluidics can help to enhance and accelerate chemical and biochemical screening, protein crystallization, enzymatic kinetics, and assays. Moreover, the control provided by droplets in microfluidic devices can lead to new scientific methods and insights.     

Conferences in Chemistry Held in 2022

Russian Chemical Bulletin -     

Interpretation of inorganic arsenic metabolism in humans in the light of observations made in vitro and in vivo in the rat

The toxicity of inorganic trivalent arsenic for living organisms is reduced by in vivo methylation of the element. In man, this biotransformation leads to the synthesis of monomethylarsonic (MMA) and dimethylarsinic (DMA) acids, which are efficiently eliminated in urine along with the unchanged form (As_i). In order to document the methylation process in humans, the kinetics of As_i, MMA and DMA elimination were studied in volunteers given a single dose of one of these three arsenicals or repeated doses of As_i. The arsenic methylation efficiency was also assessed in subjects acutely intoxicated with arsenic trioxide (As₂O₃) and in patients with liver diseases. Several observations in humans can be explained by the properties of the enzymic systems involved in the methylation process which we have characterized in vitro and in vivo in rats as follows: (1) production of As_i metabolites is catalyzed by an enzymic system whose activity is highest in liver cytosol; (2) different enzymic activities, using the same methyl group donor (S-adenosylmethionine), lead to the production of mono- and di-methylated derivatives which are excreted in urine as MMA and DMA; (3) dimethylating activity is highly sensitive to inhibition by excess of inorganic arsenic; (4) reduced glutathione concentration in liver moderates the arsenic methylation process through several mechanisms, e.g. stimulation of the first methylation reaction leading to MMA, facilitation of As_i uptake by hepatocytes, stimulation of the biliary excretion of the element, reduction of pentavalent forms before methylation, and protection of a reducing environment in the cells necessary to maintain the activity of the enzymic systems.     

美国化学教育中的科学道德教育

介绍了近年来美国科学界维护科学道德的行动及美国某些大学化学系开设科学道德教育课程的情况     

Styrol in Polystyrol und in Styrol-Methylmethacrylat-Copolymeren

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