催化动力光度法测定痕量铁

基于稀硝酸介质中痕量铁(Ⅲ)对过氧化氢氧化甲基橙褪色反应的催化作用,建立了测定痕量铁(Ⅲ)的动力学光度法。应用了单纯形优化法作条件试验,方法的灵敏度为0．015 μg· L-1,线性范围为0-9．6 μg·L-1。用于测定活性碳中痕量铁(Ⅲ),回收率在99％至105％之间。     

流动注射在线稀释测高浓度的铁

用自行组装的流动注射 智能测铁仪对高浓度铁(Ⅱ)和铁(Ⅲ)进行在线稀释测定,该仪器的分析结果与FIA 721B型分光光度计法分析结果进行比较,结果表明,该方法有快速、准确等优点。其测量的线性范围是:铁(Ⅱ)和铁(Ⅲ)分别为0.10～5.00mg·L-1和0.10～4.50mg·L-1,采用在线稀释后为0.50～30.00mg·L-1铁(Ⅱ)和0.50～20.00mg·L-1铁(Ⅲ)。测定频率为40个样品·h-1;RSD<5%,能满足工业企业分析监测的需要。     

氯丙嗪荧光光度法测定痕量铁(Ⅲ)

氯丙嗪是一种治疗精神病的药物,具有安定镇静作用和镇吐作用,已报道的方法有用氯丙嗪对S2O82-[1]、金(Ⅲ)[2]、钒(Ⅴ)[3]、砷(Ⅴ)[4]的快速定性检定,尚未见到用荧光法定量测定铁(Ⅲ)。鉴于氯丙嗪有一定的荧光强度,在一定条件下与铁(Ⅲ)络合后,荧光强度减弱,因而建立了用氯丙嗪作络合剂荧光光度法测定痕量铁(Ⅲ)的方法。结果表明:在pH为3.0的盐酸溶液中,氯丙嗪盐酸溶液的最大激发、发射波长为270,547 nm,铁(Ⅲ)的质量浓度在0.56~2.5 mg·L-1范围内,氯丙嗪的荧光猝灭程度ΔF与铁(Ⅲ)的质量浓度呈线性关系。本方法用于人发中痕量铁的测定,得…     

间接吸光光度法测定废水中二苯胺

利用铁(Ⅲ)-邻菲啰啉混合液为显色剂间接光度法测定废水中二苯胺。对该法的测定条件、回收率进行了研究,结果表明,二苯胺在1～10mg·L-1范围内,线性关系良好,回收率为92.2％～98.6%,精密度较好。     

薄层树脂相光度法测定环境水样中痕量Fe(Ⅲ)和Fe(Ⅱ)

天然水(除雨水外)中一般都含有铁盐,地下水中含亚铁盐较多,因空气的氧化,地面水中主要以Fe(Ⅲ)存在。天然水中含铁量一般较低,不致于影响人体健康,但是如超过0.3 mg·L-1则会产生特殊气味而不适于食用。工业上则视其用途有不同要求[1],如纺织、染色、造纸工业上用水含铁量不能超过0.2 mg·L-1。铁也是维持人体正常新陈代谢的重要元素之一,所以环境中铁的测定具有一定意义。近年来,有关树脂相光度法单独测定Fe(Ⅲ)和Fe(Ⅱ)的研究已有报道[2~4],本文在文献[2]的基础上,利用Fe(Ⅲ)和Fe(Ⅱ)能在弱酸性条件下与1,10-二氮杂菲(phen)生成稳定有…     

Fe(Ⅲ)-磺基水杨酸-甲基紫-聚乙烯醇体系光度法测定痕量铁

提出了在聚乙烯醇存在下,Fe(Ⅲ)-磺基水杨酸-甲基紫三元配合物光度法测定Fe(Ⅲ)的方法.该法灵敏度高(ε=3.44×105L@mol-1@cm-1),选择性及精密度均好,用于水中痕量铁的测定,结果满意.     

简讯

双波长标准加入吸光光度法同时测定锌汞国防科技大学研究了一种利用化学计量学原理改善分析方法选择性的计算分析方法——双波长标准加入吸光光度法(简称双标法)。双波长吸光光度法用于多组分相互干扰体系的测定,主要有等吸收点法和系数倍率法等。这两种方法通常是测量信号下降以消除共存物干扰,改善选择性,但在一定程度上     

痕量铁的催化分光光度法研究

研究了在S2SO4介质中，以1，10－二氮菲为活化剂，铁（Ⅲ）催化过氧化氢氧化甲基橙的褪色反应的动力学条件。建立了测定痕量铁（Ⅲ）的动力学分析法。方法的灵敏度1．78×10－8g·L－1，线性范围0～1．2×10－5g·L-1。用于测定饮用水和湖水中的痕量钱，相对标准差在5％以内，平均回收率97％～106％。     

罗丹明6G荧光光度法测定痕量铁(Ⅲ)

铁是广泛存在于自然界的金属元素,是应用最广泛的金属材料元素,也是人体必须的微量元素。痕量铁的测定方法很多,如火焰原子吸收光谱法[1]、分光光度法[2]、催化动力学法[3]、电化学发光法[4]等。测定痕量铁的荧光分析法较少,本研究发现,在稀硫酸溶液中,铁(Ⅲ)与碘化钾反应生成碘分子(I2),碘分子与罗丹明6G反应,使其发生荧光淬灭反应,荧光淬灭值ΔF在一定范围内与铁(Ⅲ)浓度呈线性关系。椐此建立了测定痕量铁(Ⅲ)的荧光光度法。方法用于蔬菜、树叶与水中痕量铁的测定。1试验部分1.1主要仪器与试剂日立850型荧光分光光度计;GFY-160型荧光分…     

4,5二溴邻硝基苯基荧光酮与铁显色反应及其应用

邻硝基苯基荧光酮属于三羟基荧光酮显色剂,已用于多种元素的光度分析[1]。本文对其衍生物4,5 二溴邻硝基苯基荧光酮(DBO NPF)与铁(Ⅲ)的反应进行了研究,结果表明,此显色反应的灵敏度高,体系的选择性和稳定性较好,可用于茶叶和头发中铁的测定,结果满意。1　试验部分1.1　主要仪器与试剂722型光栅分光光度计(上海第三分析仪器厂)铁(Ⅲ)标准溶液:10mg·L-1,5mg·L-1邻苯二甲酸氢钾缓冲溶液:pH4.0DBO NPF乙醇溶液:0.4g·L-1溴化十六烷基三甲基铵(CTMAB)溶液:2g·L-11.2　试验方法加铁标准溶液5μg于25ml容量瓶中,缓冲溶液5.0ml,DB…     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of tetrabenzoporphins of the basis of isoindoline

Chemistry of Heterocyclic Compounds -