【作者】 岳宣峰；

【导师】 张志琪；

【作者基本信息】 陕西师范大学 ， 分析化学， 2002， 硕士

【摘要】 化光度法属于分析化学中动力学分析的一个分支，是一门近代发展起来的新的测试技术。由于其具有仪器设备简单，操作简便且灵敏度高等特点，因此发展速度很快。八十年代以来，分析工作者又将流动注射技术引入催化动力学分析领域，使许多传统溶液处理方法的基本操作得以在线、快速、密闭、自动地完成，从而弥补了采用动力学分析时，反应条件不易控制，试剂消耗大，分析速度慢等缺点，极大地推动了催化动力学分析法的进展。本文以溴酸钾氧化结晶紫为指示反应，以分光光度计为检测器，分别建立了流动注射催化光度法测定亚硝酸根，甲醛的新方法。在此基础上，分别以还原柱在线还原硝酸根和氧化柱在线氧化甲醇，建立了流动注射催化光度法同时测定亚硝酸根和硝酸根、甲醇和甲醛的新方法，本文包括综述和研究报告两部分。第一部分：流动注射催化光度分析综述介绍了催化光度法近六年来的研究现状。概述了近几年来基于流动注射技术建立起来的催化光度法。简单介绍了流动注射催化光度法同时测定中所采用的溶液处理方法及数据处理手段。展望了流动注射催化光度法及其他分析技术对光度法未来的影响。第二部分：包括四个研究报告，两个催化动力学光度法单组分测定新方法和两个催化动力学光度法两组分同时测定新方法。 首先以结晶紫-溴酸钾体系为指示反应，建立了流动注射催化光度法测定超痕量亚硝酸根的新方法。在稀磷酸介质中，在丙三醇存在的情况下(丙三醇在本体系中具有增敏和消除管路中气泡的作用)，在70℃恒温水浴中加热反应盘管，测定亚硝酸根的线性范围为0.05-5ng／mL，检出限为0.02ng／mL，11次平行测定的相对标准偏差小于2％，分析速度为每小时72样。结合离子交换分离技术方法应用于雨水、药物、蔬菜中痕量亚硝酸根的测定，并进行了对照试验和回收试验，结果令人满意。 基于在磷酸介质中亚硝酸根对溴酸钾氧化结晶紫的催化作用，采用镀镉锌片还原柱在线还原硝酸根为亚硝酸根和还原柱隔离双样注入技术，建立了流动注射催化光度法同时测定亚硝酸根和硝酸根的新方法。 此流动系统产生一个带有肩峰的主峰曲线，其中肩峰高度对应于亚硝酸 根的含量，而主峰高度对应于硝酸根和亚硝酸根的总量。本方法对硝酸 根和亚硝酸根的检出限分别为 1．ong ml－‘和 0．3ng ml”’，适合于不同水样中 两种离子的同时测定，对硝酸根和亚硝酸根的检出限分别为1刀ng ml“’ 和 0．3ng ml－’，对硝酸根和亚硝酸根浓度t匕（ng ml－‘／ngml“’）在 150：l－ 3：50 之间的混合组分只要适当稀释便可以不经分离直接测定，分析速l度为每。］、时32－33 样，11 次平行测定两种离子的相对标准偏差都。J、于 2％。 研究了酸性介质中甲醛对溪酸钾氧化结暴紫反应的催化作用并结合 停留枝术，建立了流动注射催化光度法测定微量甲醛的新方法。在 7 0 OC 恒温水浴中力。热反应盘管，停留时间为 旧 秒，其坝j定的线性范围为 0＊ 18－1．4 p g i L－‘，检出限 为 0．0 0 7 p g i L”’，11次平行测定的相对标准 偏差小于2．5％，分析速度为15样／小时。结合离子交换技术除去可能 的千扰，利用此法测定了空气、中密度板和涂料中的甲醛，分析结果与 碘量法的测定结果进行了比较，结果基本相符。 基于在磷酸介质中甲醛对涣酸钾氧化结晶紫的催化作用，并通过使 用PbOZ氧化柱使甲醇在线氧化成甲醛，建立了流动注射催化光度法同时 测定甲醇和甲醛的新方法，采样时使用了三个采样环，其中只有一个通 过氧化柱，注样时通过氧化柱的样品带夹在另外两个样品带之间，监测 氧化还原反应中指示剂结晶紫的吸收曲线，结果将产生一个两侧带有肩 峰的主峰吸收曲线，其中肩峰峰高对应于甲醛的含量，而主峰峰高则对 应于甲醇和甲醛的总量。对甲醇和甲醛的检出限分别为 1．5 u g mlJ和 0＊ v g ml”’，分析速度为每小时 10样，对甲醇和甲醛的浓度比（ng ml－’／ng 二l”‘）在 500：l－l：5之间的混合组分只要适当稀释便可不经分离直接 测定，11次平行测定两种离子的相对标准偏差都，1、子 2．5o。用于合成样 中甲醇和甲醛的同时测定，结果令人满意。更多还原

【Abstract】 Catalytic spectrophotometric method , as a branch of kinetic methods in analytic chemistry, is a useful technique in the determination of trace and ultratrace substances. It enjoys great generality in most laboratory for its high sensitivity, inexpensive instruments and simple operation. When it came into eight decades, analysts combined the technique of flow injecton with catalytic method, which compensated many drawbacks when traditional catalytic spectrophotometric is adopted such as low analysis speed, high regeant cost and inconvenient control of analysis condition, and which greatly promoted the development of catalytic spectrophotometric method.There are two parts in this thesis.Part one: review? The new development of traditional catalytic spectrophotometric method during last six years, among which new approaches, new system, performance enhancement and so on are exploited.? The new development of flow-injection catalytic spectrophotometric method.? Simple introduction of approaches for on-line solution treatment and calibration in flow injection catalytic spectrophotometric methods for simultaneous determination.? Prospect of catalytic method and other techniques for spectrophotometry is presented.Part two: study reportsIn this part, four new catalytic spectrophotometric methods have been established by flow injection technique.First, a new FI catalytic spectrophotometric method using theindication reation between bromate and crystal violet is proposed for the determination of ultratrace amount of nitrite. In dilute phosphoric acid medium, in the presence of propanetriol(propanetriol can enhance sensitivity and deform in the reaction coil) and reaction temperature at 70 癈 , the linear range is 0.05-5ng/mL and the detection limit is 0.02ng/mL. The relative standard deviation of 11 replicate determinations is less than 2%. 72 samples can be analysed per hour. Combining with the separation techinique of ionic exchange, the method has been applied to the determination of trace amount of nitrite in the sample of medicine, vegetable and rain water. The comparison and recovery tests have also been carried out, and satisfactory results is obtained.Secondly, on the basis of the first method, a FI catalytic spectrophotometric method for simultaneous determination of nitrate and nitrite is proposed, in which nitrate is reduced on-line to nitrite by a cadium-coated zinc colume and two sampling loops are kept apart by reducing colume. A peak with a shoulder on the ascending part of the analytical signal is produced. The height of the shoulder corresponds to the nitrite concentration and the maximum of the peak correlates with the sum of both nitrite and nitrate. The linear range is l-50ng/mL for nitrite and 3-150ng/mL for nitrate. Detection limit is 0.3ng/m L and 1.0 ng/m L, respectively. The relative standard deviation of 11 replicate determinations of nitrate or nitrite is all less than 2%. 32-33 samples can be analysed per hour. Combining with the separation techinique of ionic exchange, the method has been applied to the determination of both the ions in various waters. The comparison and recovery tests have also been carried out, and satisfactory results was obtained.Thirdly, a new FI catalytic spectrophotometric method is proposed for the determination of trace amount of formaldehyde. In dilute phosphoric acid medium and reaction temperature at 70 癈, stop flow 180s, the linear range is 0.018-1.4 M g/mL and detection limit is 0.007 u g/mL. The relative standard deviation of 11 replicate determinations is less than 2.5%. 15 samples can be analysed per hour. Combining with the separation techinique of ionic exchange, the method has been applied to the determination of traceIVamount of formaldehyde in the samples of air, paint and decoration board. The comparison and recovery tests have also been carried out, satisfactory results was obtained.Finally, on the basis of the third method, a FI catalytic spectrop更多还原