中俄界河联合监测2,4-二氯酚和2,4,6-三氯酚分析方法的异同

本文对中俄跨界水体水质联合监测工作中的2,4-二氯酚和2,4,6-三氯酚两项的各自的国标分析测试方法进行了实验比对,并对分析结果进行了总结。采用中俄两国分析方法测定精密度、准确度和方法检出限。研究结果表明:在严格按照方法规范操作情况下,两国的分析结果差异不大。本文对两国的实验操作过程和试剂对实验室环境的污染等方面进行了探讨。

Studies on Mechanism of Chemiluminescence Reaction of 2, 6, 7-Trihydroxyl -9- (4'-chlorophenyl ) -3-fluoroner

Catalytic chemiluminescence of over twenty metallic ions in the systemof 2, 6, 7-tihydroxyl-9- (4'-chlorophenyl)-3-fluorone (Cl-PF )-H2O2 has been tested.Trace amount of Co(Ⅱ) strong1y catalysed this chemiluminescence reaction, especiallyin presence of cationic surfactant cetyltrimethylammonium bromide (CTMAB), andthe chemiluminescence intensity was proportional to the concentraction of Co(Ⅱ) in therange 0. 5~6ng. ml-1 Co(Ⅱ). Two steps could be involved in the chemiluminescentreaction of C1-PF. In alkaline solution, the O2 radical ion should attack an oxygenbridge between the benzene rings of Cl-PF with break in oxygen bridge bond to produce reaction product which is excited by the energy derived from this chemical reaction. The electronic excited state emits the radiation(560 nm) on falling to the groundstate, followed by formation of polyphenol derivatives. the polyphenol derivatives arefurther oxidized to produce chemiluminescence (480 nm) which is due to emission fromsinglet oxygen.

Determination of heavy metal ion in landfill leachate with solvent extracting ＆ fluorescence quenching method

Add the masking agent and biscyclohexanoneoxalyldihydraone into the diluted clarificd liquid of the landfill leachate which was treatmented by digestion and centrifugal filtration to complexate all heavy metal ion in the trcatmented liquid, and extracted using CHCl3 many time, then it were demasking and decomposing respectively, and adjusted different pH and formed Me^n＋-PAN coordination compound when these metal ion reaction with PAN. The Fluoresence quenching of Rh6G （λex/λem=543mn/558nm） when the metal ion coordination compound was add into the Rh6G solution step by step, the quenching intensity was directly proportional to the concentration of the metal ion in the certain range. So a new method of fast and simple for determination of trace metal ion in landfill lcachate was established to determine metal ion in sample of different landfill leachate in Three Gorge Water Reservoir, and comparison the classic assay method with satisfactory results.

有机金属盐VC-Ca的合成初探

有机金属盐ＶＣ－Ｃａ的合成初探高远浩（平顶山师专化学系）１引言维生素Ｃ［１］和活性钙都是人体生命不可缺少的物质，其医疗和保健作用早已为人类所熟知．但同时具有维生素Ｃ和活性钙双重功效的新物质国内尚无报道．本文在分析了维生素Ｃ结构特征的基础上，以自然界富...

测定蔬菜中还原型维生素C两种方法的比较

采用钼蓝比色法和2,6-二氯靛酚滴定法测定蔬菜中还原型维生素C含量。结果表明,钼蓝比色法测定蔬菜中还原型维生素C含量,其相对标准差在0.87%～2.59%,回收率在97.20%～103.20%;2,6-二氯靛酚滴定法相对标准差在1.37%～6.07%,回收率在91.20%～103.70%。钼蓝比色法的准确度及精确度均高于2,6-二氯靛酚滴定法,且操作简便、快速,不受样液颜色的影响。

都匀毛尖茶维生素C含量的测定

为了探明优质名茶都匀毛尖茶维生素C含量,对都匀三个茶场的毛尖茶12个样本水浸出物,采用分光光度法和2,6-二氯酚靛酚法对茶汤维生素C含量进行测定,结果表明:三个茶场的毛尖茶水浸出物维生素C含量均高;低温贮藏比常温保存的茶叶维生素C含量高;维生素C含量随海拔高度而增多。维生素C通过浸泡从茶叶中释出进入茶汤构成优质名茶都匀毛尖茶。这两种方法简便易行。

不同果蔬Vc含量的比较研究

采用2,6-二氯酚靛酚滴定法对北方地区常见的27种水果、蔬菜中所含维生素C的量进行测定。结果表明,所测水果中枣的维生素C含量最高,其次为猕猴桃、山楂、草莓、橙子、葡萄、芒果和菠萝。香蕉、梨和苹果中维生素C含量相对较少。所测蔬菜中辣椒维生素C含量最高,其次为菜花、西兰花和香菜,芹菜茎中维生素C含量相对较少。蔬菜中维生素C含量普遍高于水果中维生素C含量。

分光光度法测定面粉中三聚氰胺

研究的目的是寻找一个采用分光光度法测定三聚氰胺含量的方法。对不同的显色剂、吸收波长、显色剂用量、pH值、显色时间、温度等进行了条件试验。结果表明,采用2,6-二氯酚靛酚钠-丙酮显色剂,在20～30℃,显色15min,在634nm条件下有最大吸收。测定范围为40μg/mL～800μg/mL,线性相关系数r0.9986。面粉中的三聚氰胺用0.1%三氯乙酸溶液和2%乙酸铅溶液消除样品中的干扰物质(主要是蛋白质),加标回收率为95.59%～98.64%。该方法检测灵敏度、准确度及精密度完全满足日常检测要求,且简便可行,设备价廉。

优选维Vitamin C测定方法在果蔬中的应用

目的:为完善药品、食品中维生素C含量测定方法,指导合理摄入维生素C,正确推广健康饮食,找到一种准确快速测定维生素C含量的方法。方法:采用直接碘量法、2,6-二氯酚靛酚法、紫外分光光度法、荧光分光光度法测定维生素C的含量,系统比较维生素C含量测定的方法优缺点。结果:直接碘量法、2,6-二氯酚靛酚法、紫外分光光度法、荧光分光光度法(邻苯二胺体系、苯甲酸体系)测得维生素C片中维生素C的含量绝对误差分别为0.094mg/mL,0.095mg/mL,0.357mg/mL,0.120mg/mL,0.009mg/mL。结论:在苯甲酸体系,采用荧光分光光度法测得维生素C的含量准确度高,操作简易,方便应用于果蔬中维生素C测定。