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1.
阻抑动力学光度法测定痕量邻二硝基苯   总被引:13,自引:0,他引:13  
刘钦伟  陈国树 《分析化学》2001,29(3):258-261
研究发现 ,在盐酸介质中 ,痕量邻二硝基苯能灵敏地阻抑高碘酸钾氧化中性红褪色。中红性、盐酸、高碘酸钾的最佳用量分别为 0 5 5 ,0 6 0 ,0 6 0mL ,反应温度 80℃ ,反应时间 6min。研究了该阻抑褪色反应的最佳条件及动力学参数 ,建立了一种测定痕量邻二硝基苯的新方法。该法测定线性范围为0 0~ 4.0 μg/L ,检测限为 7.7× 10 -7g/L。用于环境水样中邻二硝基苯的测定 ,结果满意。  相似文献   

2.
萃取催化光度法测定痕量铜   总被引:16,自引:2,他引:14  
研究了在pH5.5的弱酸性介质中,利用邻菲罗啉活化铜(Ⅱ)催化过氧化氢氧化邻氨基酚显色的指示反应,用萃取平衡控制反应时间,水相中邻氨基酚的浓度和反应程度,建立了萃取催化光度法测定痕量铜的新方法。方法的线性范围为0.00050 ̄0.10mg/L,检测限为5.0×10^-7g/L。用于水和粮食中痕量铜的测定,结果满意。  相似文献   

3.
阻抑动力学光度法测定痕量间二硝基苯   总被引:2,自引:1,他引:2  
在盐酸介质中,痕量间二硝基苯能灵敏地阻抑Fe^3 催化高碘酸钾氧化孔雀绿的反应。研究了该阻抑反应的最佳条件及动力学参数,建立了测定痕量间二硝基苯的新方法,间二硝基苯的线性范围为0.0-10.0μg/L,检出限为1.8μg/L。该法灵敏、简便,选择性好,用于环境水样中间二硝基苯的测定,结果准确。  相似文献   

4.
固相微萃取/气相色谱/质谱联用测定水中的2,4-二硝基苯酚   总被引:16,自引:0,他引:16  
路鑫  赵欣捷  叶芬  许国旺 《色谱》1999,17(2):131-133
研究了水中痕量2,4-二硝基苯酚的固相微萃取(SPME)方法,得到了2,4-二硝基苯酚的SPME最佳萃取条件:水溶液调pH2,并用NaCl他和,在室温下直接萃取30min,气相色谱/质谱分析时,纤维探针在270℃下脱附3min。所建立的方法适于快速、方便地测定水中2,4-二硝基苯酚,不需浓缩和预处理。  相似文献   

5.
阻抑动力学光度法测定痕量间二硝基苯的研究   总被引:3,自引:0,他引:3  
研究发现 ,在硫酸介质中 ,痕量间二硝基苯能灵敏地阻抑 Fe3+催化高碘酸钾氧化甲基兰褪色。研究了该阻抑褪色反应的最佳条件及动力学参数 ,建立了一种测定痕量间二硝基苯的新方法。该法测定线性范围为 0 .0~ 8.0μg/L,检出限为 1 .6× 1 0 - 6 g/L。用于环境水样中间二硝基苯的测定 ,结果满意  相似文献   

6.
建立了气相色谱法测定甲醇中邻二硝基苯、间二硝基苯、对二硝基苯、邻硝基氯苯、间硝基氯苯、对硝基氯苯、2,4-二硝基氯苯7种硝基苯混合溶液的方法。采用Rxt-5MS型色谱柱(30 m×0.25 mm,0.25μm),设置程序升温,使用FID检测器进行测定,分析了7种硝基苯的色谱保留时间与理化性质的关系。7种硝基苯的质量浓度在10~200μg/mL范围内与色谱峰面积线性关系良好,相关系数均大于0.999,方法检出限为0.003~0.007μg/mL。测定结果的相对标准偏差为0.62%~4.03%(n=6),样品加标回收率为95.7%~101.4%。该方法适用于环境中硝基苯检测。  相似文献   

7.
在硫酸介质中,痕量间二硝基苯能灵敏地阻抑Fe3+催化H2O2氧化中性红染料褪色的反应,由此建立了一种测定痕量间二硝基苯的阻抑动力学光度法。采用固定时间法,在λmax=530 nm处,对阻抑体系和非阻抑体系进行光度测定,应用正交试验法确定该阻抑褪色反应的最佳实验条件,并测定了其反应级数。该方法线性范围为0~48μg/L,检出限0.103μg/L,回收率为97.8%~98.9%,测定结果的相对标准偏差为1.5%~2.1%。该方法用于环境水样中间二硝基苯含量的测定,测定结果可靠。  相似文献   

8.
催化光度法测定痕量亚硝酸根   总被引:6,自引:0,他引:6  
寻找新指示物质,建立新催化动力学体系用于亚硝酸根测定能显著提高测定的灵敏度,特别是在水体及食物中痕量亚硝酸根的测定中,具有很重要的意义。本文利用亚硝酸根能灵敏地催化高碘酸钾氧化N-苯基邻氨基苯甲酸显色的反应,建立了测定痕量亚硝酸根的新方法,固定反应时间,并加入一定量的氢氧化钠溶液,以冷水流冷却,可使该催化反应中止。其反应机理为:  相似文献   

9.
研究了在碱性介质中,以邻菲啰啉为活化剂,锰(Ⅱ)催化高碘酸钾氧化苯酚红褪色指示反应及其动力学条件,建立了测定痕量锰的新方法。锰的浓度在0~0.07μg/mL范围内为线性关系,检测限为3.0ng/mL。用于盐酸试剂中痕量锰的测定,结果良好。  相似文献   

10.
动力学光度法测定痕量邻菲咯啉   总被引:3,自引:0,他引:3  
在稀醋酸介质中,痕量邻菲咯啉对高碘酸钾氧化玫瑰桃红R褪色反应有明显的催化作用,据此建立了测定邻菲咯啉的催化动力学光度法。讨论了反应的动力学参数。方法的线性范围为0.005—0.1mg/L;检出限为3.0μg/L。方法灵敏度高,简便,快速,选择性好,用于合成水样及废水、河水中邻菲咯啉含量的测定,结果满意。  相似文献   

11.
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.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

16.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

17.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

18.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

19.
袁丽秋 《化学教育》2006,27(5):8-10
面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。  相似文献   

20.
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