雕白粉与食品亚硫酸盐漂白剂

本文分析了目前社会上反应强烈的在食品中所添加的雕白粉的毒性,对食品工业中使用的亚硫酸及其盐类漂白剂的漂白、抗氧化、防腐及可能的毒副作用进行了综述.     

雕白粉与食品亚硫酸盐漂白剂

本文分析了目前社会上反应强烈的在食品中所添加的雕白粉的毒性，对食品工业中使用的亚硫酸及其盐类漂白剂的漂白、抗氧化、防腐及可能的毒副作用进行了综述。     

关于7种含氧酸结构与酸性的讨论

含氧酸是无机化学授课的一个重要内容,讨论了含氧酸中亚硫酸、硼酸、次磷酸、亚磷酸、溴酸、亚溴酸、碳酸的结构与酸性。研究表明,SO2溶液中存在着2种异构体;硼酸在不同条件下存在Lewis酸和Brönsted酸2种形式;次磷酸、亚磷酸、溴酸、亚溴酸都存在着异构化倾向;在一定条件下,碳酸具有一定的动力学稳定性。     

生物系统活性氧及其反应与损伤致病作用

从量子化学概念评述活性氧毒性结构原理 ,总结生物系统活性氧基本反应 ,绘制出活性氧转化关系图 ,由图分析活性氧产生、转化、损伤作用和对其清除防御 ,以及这些反应与疾病和衰老的关系。简介这一领域的进展和动向。     

离子液体毒性、生物降解性及绿色离子液体的设计与合成

离子液体作为溶剂或催化剂在化学反应、分离过程、电化学及其它领域中已有广泛的应用. 离子液体一直被认为是一种环境友好的“绿色溶剂”, 最近几年其潜在的毒性、生物降解性及绿色离子液体的设计与合成才引起人们的重视. 综述了近年来该领域的研究进展.     

车用燃料电池现状与电催化

本文综述了近年来车用燃料电池电催化的发展状况,分析了车用燃料电池电催化的发展趋势,重点介绍了大连化学物理研究所在燃料电池电催化方面的研究进展．指出车用燃料电池电催化的发展方向是提高现有铂基催化剂的活性,在保证车用燃料电池在变载等动态工况下的可靠性与寿命的前提下,应降低膜电极的贵金属铂用量,发展低铂／非铂电催化剂．针对车用燃料电池的使用条件,应发展抗燃料气与空气中杂质的电催化方法与抗腐蚀催化剂载体．从长远考虑,重点发展碱性聚合物膜燃料电池,拓展利于活化顺磁性氧的催化方法,有望摆脱车用燃料电池对铂催化剂的依赖．     

对“化学与生活”模块中“食品添加剂”内容的教学设计研究——基于培养学生与生活相关的化学科学素养

从培养学生与生活相关的化学科学素养的角度对"化学与生活"模块中"食品添加剂"内容的教学设计进行了研究,设计出了以培养学生与生活相关化学素养为总目标、以真实生活问题解决为主线索的课程,并通过问卷调查和学生访谈对教学效果进行检测。     

二乙酰姜黄素金属(铜,铂)配合物的合成及其与ctDNA的键合作用

以姜黄素为原料,合成了二乙酰姜黄素(H2L)及其铜(Ⅱ)和铂(Ⅱ)配合物(CuL2和PtL2),其结构经1H NMR,IR,MS和元素分析确认。采用UV-Vis测定法和循环伏安法研究了CuL2和PtL2与ctDNA的相互作用。结果表明,CuL2和PtL2与ctDNA的作用属嵌插作用模式。     

杜鹃花科植物有毒成分的电子结构及构效关系

本文应用INDO方法, 对由杜鹃花科植物中提取分离的九个化合物进行了量子化学计算, 得到了分子轨道波函数等多种电子结构信息, 并计算了这些化合物活性部位的分子静电势, 得到了静电势图。用分子图形技术与药理性质相同的其它生物碱类毒素进行了空间结构比较。研究了它们的电子结构特征和活性部位, 讨论了作用机理及电子结构与毒性之间的关系。     

果菠萝蛋白酶在有机溶剂微扰时的分子折叠与活力变化的研究

本文用荧光、紫外差示及CD光谱研究果菠萝蛋白酶经甲醇、乙醇、乙二醇微扰后的构象与活力变化情况.酶的荧光强度随有机溶剂浓度增大而增强,表明Tyr、Trp微环境发生明显变化。232nm和285nm处出现紫外差吸收正峰。前峰与酶分于折叠的变化有关,而后峰与Tyr、Trp微环境的变化相关.甲醇、乙醇微扰后,天然酶的208nm和225nmCD双负峰逐渐加强,而乙二醇微扰后,225nm负峰加强。208nm负峰减弱并红移直至完全消失,说明酶分子完全伸展.     

Galvanostatic Entrapment of Sulfite Oxidase into Ultrathin Polypyrrole Films for Improved Amperometric Biosensing of Sulfite

The entrapment of sulfite oxidase (SOx) into ultrathin polypyrrole (PPy) films of 27–135 nm thickness has been successfully used for amperometric biosensing of sulfite with considerably improved performance. Optimum galvanostatic entrapment was accomplished in an electrolyte‐free solution which contained 0.1 M pyrrole and 5 U/mL of SOx with a polymerization period of 120 seconds and an applied current density of 0.2 mA cm^?2. Evidence of the incorporation and retention of SOx in the ultrathin PPy film was obtained by scanning electron microscopy, cyclic voltammetry and amperometric measurements. Entrapment of the enzyme in a 54 nm thick PPy‐SOx film gave optimum amperometric response for sulfite and enabled the detection of as little as 0.9 μM of sulfite with a linear concentration range of 0.9 to 400 μM. The successful application of the biosensor to the determination of sulfite in beer and wine samples is reported. Comparison with a spectrophotometric method indicates that the biosensor was more superior for the determination of sulfite in red wine.     

New Spectrophotometric Method for Sulfite Determination

Abstract

A highly selective spectrophotometric method for the determination of aqueous sulfite was developed. Sulfite was found to react with o-phthaldialdehyde in presence of ammonia yielding a deep blue colored complex the absorbance of which is sensitive to trace sulfite concentrations. The method is simple, very sensitive, and convenient for the determination of as little as 5X10^?6 M sulfite. The molar absorptivity of the colored complex is about 1.2X10⁴ L cm^?1 mol^?1. The proposed method is more sensitive and selective for sulfite than the widely used Ellman reagent method. Absorbance is measured at 628 nm which is the best of the two absorption maxima that are exhibited by the compound.     

簇合物膜亚硫酸根离子选择性电极的研制

报道了复ＭｏＳ６２－４在铜表面形成不溶性族合物膜的性质，研制了一种簇合物膜亚硫酸根离子选择电极。电极对ＨＳＯ＾－３的线性响应范围为１×１０＾－４－１×１０＾－１ｍｏｌ／Ｌ；检测限为８×１０＾－５ｍｏｌ／Ｌ；响应斜度为５８．５ｍＶ／ｄｅｃ；适宜的ｐＨ范围为９－１０。     

Sulfite oxidase biosensors based on tetrathiafulvalene modified screen-printed carbon electrodes for sulfite determination in wine

Screen-printed carbon electrodes have been modified with tetrathiafulvalene and sulfite oxidase enzyme for the sensitive and selective detection of sulfite. Amperometric experimental conditions were optimized taking into account the importance of quantifying sulfite in wine samples and the inherent complexity of these samples, particularly red wine. The biosensor responds to sulfite giving a cathodic current (at +200 mV vs screen-printed Ag/AgCl electrode and pH 6) in a wide concentration range, with a capability of detection of 6 μM (α = β = 0.05) at 60 °C. The method has been applied to the determination of sulfite in white and red samples, with averages recoveries of 101.5% to 101.8%, respectively.     

Development and Application of an Immobilized Enzyme Electrode for the Determination of Sulfite in Foods and Feeds

Abstract

An enzyme electrode was developed using the enzyme sulfite oxidase (EC 1.8.3.1) immobilized onto pig intestine. All experimental parameters such as pH, temperature, buffer constituent concentration, etc., were thoroughly investigated and optimized when appropriate. Hydrogen peroxide was monitored amperometrically. The response to sulfite concentration was linear in the range of 5.2 × 10^?6 to 1.0×10^?3M. The proposed method was found to have a correlation coefficient of 0.952 when evaluated versus the standard titration method.     

硒（Ⅳ）—碘酸钾体系极谱法测定痕量亚硫酸根

报道了一种单扫描极谱测定痕量亚硫酸根的方法。在高氯酸介质中，亚硫酸根可将Ｓｅ（Ⅳ）还原为Ｓｅ（０），在ＰＨ１０．５的ＮＨ３－ＮＨ４Ｃｌ缓冲溶液中，在碘酸钾存在下，于－０．９０Ｖ（ｖｓ．ＳＣＥ）处产生一个灵敏的还原催化波，导数波高与亚硫酸根浓度在０－０．４ｍｇ／Ｌ范围内有线性关系，检出限为２μｇ／Ｌ。     

活细胞线粒体中SO2-3/HSO-3的荧光成像

在五甲川菁染料的基础上,合成了一种新型的中位溴取代的五甲川菁染料Cy5-Br,其结构通过质谱和核磁共振波谱表征。性能测试结果表明,该染料作为荧光探针的发射波长可达665 nm,具有较低的细胞毒性,而且对二氧化硫衍生物 SO2-3和 HSO-3具有很好的选择性。该探针在665 nm 处的荧光发射强度随着SO2-3/HSO-3浓度的增加不断降低,具有良好的线性荧光响应。 Cy5-Br可以进入活细胞线粒体,对 SO2-3和HSO-3的浓度进行实时共聚焦荧光成像。     

A Novel Fluorometry of Sulfite with High Specificity

Abstract

A highly sensitive and specific fluorometric determination method for sulfite using the reaction of N-(9-acridinyl)maleimide and sulfite in solution has been developed, in which sulfite could be determined up to 100 p mole/ml.     

Test Strip For The Rapid Identification of Sulfite on Foods

Abstract

A rapid, sensitive, test strip has been developed for those people allergic to sulfite on foods. The strip is composed of a mixture of orange I, brilliant green, and sodium hydrogen carbonate deposited on 80-120 mesh alumina. Within 15 seconds the black strip turns red in the presence of as little as 0.5 ug of sulfite or green in the absence of sulfite.