红外反射光谱法在金属表面光洁度表征中的应用

本研究利用傅里叶变换红外反射光谱技术,通过对比不同光洁度的金属表面红外反射光谱图,建立了利用傅里叶变换红外反射光谱表征金属表面光洁度的方法,本文从红外反射光谱图4000cm-1～600cm-1、3400cm-1～2600cm-1波段的斜率及4000cm-1、3000cm-1、2000cm-1波数处的反射率两方面进行考察,结果表明,斜率和某一波数处的反射率均能用来表征金属表面的光洁度,且具有较高的准确性。     

衰减全反射傅里叶变换红外光谱法同时测定叔丁醇和二叔丁基过氧化物

分别应用914 cm-1和875 cm-1处的甲基特征峰作为叔丁醇和二叔丁基过氧化物的定量分析峰,使用峰面积作为吸光度的评估方法,得到的标准曲线的相关系数(R2)分别是0.9987和0.9952,叔丁醇的加标回收率在95％～110％之间,应用衰减全反射傅里叶变换红外光谱法测定3个样品,计算结果的F值、t值和p值,数据表明衰减全反射傅里叶变换红外光谱法与气相色谱法的测定结果一致.     

傅里叶变换红外光谱法测定六氟化钨中氟化氢

设计了一套测定六氟化钨中氟化氢的进样管路,提出了傅里叶变换红外光谱法测定六氟化钨中氟化氢含量的方法。根据氟化氢的红外光谱特征性,氟化氢在3 600~4 300 cm-1波数范围内有8个特征吸收峰,为了避免水蒸气的干扰,选择波数4 038.2 cm-1作为氟化氢的定量峰位。选择氟化氢标准气体样品,按方法分析并测得相关数据。以氟化氢的体积分数(%)为横坐标,以特征峰的吸光度为纵坐标,制作标准曲线。测得标准曲线的线性范围在1.0×10-4%~1.0×10-3%之间。     

傅里叶变换红外光谱法识别分析四种天然皮革材质

以国家部分标准皮革样品及市售皮革样品等天然皮革为样品,采用傅里叶变换红外光谱仪的衰减全反射附件--OMNI采样器,收集傅里叶变换红外吸收光谱,对光谱预处理后,提取红外光谱的特征信息,以2 925 cm-1和2 854 cm-1处的吸收峰面积比值为横坐标,1652 cm-1与1 552 cm-1处的吸收峰面积比为纵坐标,用Origin 7.0化学化工制图软件绘制二维分布图,对各种皮革样品进行识别分析.结果显示:猪皮革、牛皮革、马皮革的样品点分布效果好,而羊皮革的各样品点之间比较分散;猪皮革样品点明显区别于牛皮革、羊皮革和马皮革,马皮革样品点明显区别于牛皮革、羊皮革和猪皮革,而牛皮革和羊皮革的样品点分布有交叉.     

傅里叶变换红外光谱法测定苯乙烯-异丁烯酸甲酯共聚物中苯乙烯单元含量

取0.013 g共聚物样品,用压片机在压力30 MPa和温度(150±10)℃的条件下压制成厚度为0.05 mm的样品膜供傅里叶变换红外光谱法分析用.根据苯乙烯-异丁烯酸甲酯共聚物的红外光谱特征性,分别选择波数700 cm-叫和1 730 cm-作为苯乙烯和异丁烯酸甲酯的定量峰位.选用已知苯乙烯单元的共聚物样品,按方法分析并测得相关数据.以苯乙烯单元的质量分数(%)作为纵坐标,以特征峰面积比值(A700/A1730)为横坐标制作标准曲线.根据所测得未知样品的A700/A1730比值,在标准曲线上查得其苯乙烯单元的含量.该法测定聚合物中苯乙烯单元的范围为40%～85%.测得不同苯乙烯单元含量样品的相对标准偏差(n=6)为0.9%～1.9%.将红外光谱法分析结果与核磁共振法分析结果进行比较,相对误差在2%以内.     

红外二阶导数指纹图谱用于紫花地丁药材的产地分类

建立了紫花地丁药材的红外二阶导数指纹图谱。采用傅里叶变换-红外光谱法测定10个不同产地紫花地丁试样的红外光谱,红外分辨率为8 cm-1,扫描范围为4 000~400 cm-1,利用二阶导数重构指纹图谱后,进行系统聚类分析和Fisher′s判别分析。结果表明所建立的方法能够能有效地对样品产地进行预测,可为紫花地丁药材质量控制提供一种简便、有效的手段。     

三磷酸铝的傅里叶变换红外光谱分析

提出了应用傅里叶变换红外光谱法,在由生产中产生的偏磷酸铝和磷酸二氢铝杂质存在下测定三磷酸铝(AlH2P3O10.2H2O)。从红外吸收光谱可见,三磷酸铝(Al-TP)及偏磷酸铝(Al-MP)分别在波数为986 cm-1及740 cm-1处存在特征吸收峰,而磷酸二氢铝在此波段无吸收峰。据此提出,用Al-MP作内标,以Al-TP与Al-MP的峰高比值与两者相应的浓度比值图,并采用曲线拟合或最低基线计算法制得工作曲线。由此可求得试样中Al-TP与Al-MP的含量比值。由于采用了Al-MP作内标,其干扰也得到消除。同时用标准(浙B/HG 204-88及GB/T 1714-1979)中所述方法对样品中磷酸二氢铝及水分的含量分别予以测定。按文中所给的公式,计算样品中三磷酸铝的含量。     

傅里叶变换红外吸收光谱识别五种植物油的研究

以花生油、大豆油、芝麻油、棉籽油和米糠油为样品,采用傅里叶变换红外光谱仪,采集傅里叶变换红外吸收光谱,对光谱预处理后,提取红外特征信息,以1746cm-1和2855cm-1处的吸收峰面积比值为横坐标,1099cm-1处与1119cm-1处的吸收峰面积比为纵坐标,在Origin6.0上做出二维分布图,对各种油脂进行识别分析。结果显示,大豆油与其它4种油脂之间有明显区分;大豆油、花生油和芝麻油分布效果好,但棉籽油各样品点之间比较分散;能与其它油脂区分开的有以下几种分布花生油明显区别于芝麻油、棉籽油和大豆油;米糠油明显区别于棉籽油和大豆油。分布有交叉的油脂有米糠油与花生油或芝麻油有交叉,棉籽油与芝麻油有交叉。     

衰减全反射-傅里叶变换红外光谱法测定橙子油中柠檬烯的含量

应用衰减全反射傅里叶变换红外光谱法测定橙子油中柠檬烯的含量。柠檬烯的特征峰(1 645.1±1)cm-1为定量测量峰,测定样品在15min内完成。柠檬烯的体积分数在9.60%~76.8%范围内与测量峰峰高呈线性关系。以橙子油样品为基体进行加标回收试验,所得回收率在99.7%~101%之间,测定值的相对标准偏差(n=5)为1.1%。     

基于波数校准下傅里叶红外气体分析仪模型传递的研究

傅里叶变换红外光谱仪具有扫描速度快、分辨率高、波数精度高、灵敏度高和光谱范围宽等优点,因而应用于各个领域.但在实际应用中,由于仪器间的差异、仪器自身随时间的变化或者样品特性等问题,导致在一台仪器上建立的校正模型不能推广至其他仪器长期使用,使得傅里叶变换红外光谱法(FTIR)的应用受到了校正模型的限制,因此如何实现整机的...     

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.     

Conferences in Chemistry Held in 2022

Russian Chemical Bulletin -     

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.     

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。     

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     

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.     

Trends in education in analytical chemistry

Summary At the session of the WPAC of Fechem on education in analytical chemistry it was concluded that it is now essential to include chemometrics and basic knowledge of computers in all courses on analytical chemistry.

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Tendenzen in der analytisch-chemischen Ausbildung

Zusammenfassung Bei einer Tagung der WPAC über die Lehre auf dem Gebiet der analytischen Chemie wurde bei der Betrachtung neuer Aspekte festgestellt, daß vor allem Chemometrie und Grundkenntnisse in Computertechnik in die Ausbildung aufgenommen werden sollten.