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1.
溴酸钾氧化靛红催化光度法测定痕量亚硝酸根   总被引:14,自引:3,他引:11  
基于磷酸介质中NO2^-催化溴酸钾氧化靛红的褪色反应,建立了测定痕量NO2^-的新方法,并讨论了其动力学条件。方法检测限为1.36×10^-6g/L,线性范围0.3 ̄2μg/25mL,方法简便,已用于环境水样中痕量NO2^-的测定。  相似文献   

2.
溴酸钾氧化溴百里酚蓝催化光度法测定痕量亚硝酸根   总被引:9,自引:2,他引:7  
基于磷酸介质中NO2^-催化溴酸钾氧化溴百里酚蓝的褪色反应,建立了测定痕量NO2^-的新方法。方法检出限为2.6×10^-6g.l^-1,线性范围0.4~3μg/25ml方法简便,已用于雨水塘水中痕量NO2^-的测定。  相似文献   

3.
研究了盐酸介质中,痕量亚硝酸根催化溴酸钾氧化中性红褪色反应及其动力学条件,建立了催化动力学光度法测定痕量亚硝酸根的新方法,NO^-2的测定线性范围为1-7μg/25ml,检出限为1.5*10^-8g.ml^-1。用于化学试剂及唾液中痕量NO^-2的测定,结果满意。  相似文献   

4.
王耀光  齐秀贞 《分析化学》1994,22(8):767-770
本研究了苯酚在氨性缓冲溶液中与NO2^--磺胺重氮盐偶联反应的实验条件,建立了一个灵敏快速测定痕量NO2^-的新方法。NO2^-离子浓度在1.0×10^-10--4.8×10^-7g/ml范围内,与峰高呈良好的线性关系。4000倍量NO3^-存在不干扰。  相似文献   

5.
研究了在稀硫酸介质中,痕量NO2^-对溴酸钾氧化酸性络蓝K褪色反应的催化作用及其动力学分析,建立了测定痕量NO2^-的一性范围为0 ̄3.4μg/25ml,检出限为2.41×10^-7g·L^-1,用于水及蔬菜中痕量NO2^-的测定,结果满意。究了  相似文献   

6.
柳仁民  刘道杰 《分析化学》1994,22(12):1241-1243
基于NO2^-,NO3^-和Fe(Ⅲ)对甲基橙光化学褪色反应的催化作用,利用自制流通式光化学反应应器,建立了流动注射光化学反应同时测定NO2^-和NO3^-以及测定Fe(Ⅲ)的新方法。测定NO2^-和NO3^-的线性范围都是0.1-3.2mg/L,每小时可测30-40个样品。测定Fe(Ⅲ)的线性范围为0.06-1.2mg/L,进样频率为60-80次/h。应用于蔬菜中NO2^-,NO3^-的测定和茶  相似文献   

7.
杨维平  章竹君 《分析化学》1997,25(8):955-958
基于在酸性介质下,NO^-2与I^-快速反应产生I2和I2氧化Luminol产生化学发光反应,建立了Luminol-I^--NO ^02偶合发光体系测定痕量NO^-2R YYIUF。用于食品及水中亚硝酸 的测定,结果满意。  相似文献   

8.
催化动力学光度法测定痕量NO2^—的研究   总被引:14,自引:0,他引:14  
本文研究了在稀硫酸介质中,NO2^-对KBrO3氧化甲基橙褪色反应的催化作用及其动力学分析,建立了测定痕量NO2的新方法,该方法的检出限为1.3×10^-10μg/mL,线性范围为0.-1.4×g/10mLNO2,方法简便、灵敏、选择性好,于水及蔬菜中痕量NO2的测定,结果满意。  相似文献   

9.
本文采用单柱离子色谱系统测定了C2O^2-4,以1.3mmol/L葡萄糖酸钠/1.3mmol/L硼砂为淋洗液测定C2O^2-4,8常见阴离子Cl^-,NO^-3,HPO^2-4,SO^2-4不干扰测定,C2O^2-4的检出限为0.57mg/L,相对标准偏差为1.07%,工作曲线的线性范围为0.57-500mg/L,应用本方法测定了加C2O^2-4的自来水样,C2O^2-4的回收率为99.52%。  相似文献   

10.
催化光度法测定肉制品中亚硝酸盐   总被引:2,自引:0,他引:2  
基于亚硝酸根在稀磷酸溶液中催化文思蓝-氰钾氧化还原反应,建立了微量NO^-2的催化光度法。在最大吸收波长610nm处,NO^-2在0-3.0μg/25ml范围内呈线性关系,检出下限为3.51*10^-9g.ml^-1。方法用于肉制品中NO^-2的测定。结果满意,且与国家标准方法结果相符。  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.
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   

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.

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   

16.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.  相似文献   

17.
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   

18.
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   

19.
20.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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