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1.
基于血红蛋白的过氧化物酶特性,建立了一种测定血红蛋白的催化动力学光度分析法.在pH 9.5的缓冲溶液中,血红蛋白对过氧化氢氧化酸性铬蓝K反应体系的褪色作用明显加速.在最佳试验条件下,由于褪色作用的加速所引起的吸光度下降(△A)与血红蛋白的浓度在7.0×10-10~9.0×10-8 mol·L-1范围内呈线性关系.表观摩尔吸光率为3.9×108L·mol-1.cm-1,检出限为1.7×10-11mol·L-1.用于尿液中血红蛋白含量的测定,测定结果的相对标准偏差(n=5)在1.9%~4.2%之间,回收率在96.0%~102.0%之间.对此酶催化反应的机理也作了探讨.  相似文献   

2.
催化动力学光度法测定痕量硫氰酸根的研究   总被引:3,自引:0,他引:3  
基于硫氰酸根对碘氧化叠氮化钠的催化作用,建立了催化动力学光度法测定硫氰酸根的新方法.于352nm处分别测定催化体系和非催化体系的吸光度A和A_V,以△A=A_c-A定量,线性范围为1.0~700μg·L~-1,检出限1.0μg·L~-1.用于生物样品中痕量硫氰酸根的测定,结果满意.  相似文献   

3.
愈创木酚催化光度法测定痕量铁(Ⅲ)   总被引:1,自引:0,他引:1  
在pH 2.6的邻苯二甲酸氢钾-盐酸缓冲溶液中,在活化剂邻菲啰啉存在下,研究了痕量铁(Ⅲ)对高碘酸钾氧化愈创木酚反应的催化作用,并测定了此反应的动力学参数。于两个25 mL具塞比色管中各加0.30mol·L~(-1)愈创木酚溶液0.6mL,缓冲溶液1.5mL,1×10~(-3)mol·L~(-1)邻菲啰啉溶液2 mL及0.03mol·L~(-1)高碘酸钾溶液3mL,于其中一份中加入定量的铁(Ⅲ)溶液,另一份不加,加水定容后置于60℃±5℃水浴中加热6min,冷却后于480nm波长处测量两溶液的吸光度A及A_0,并计算△A。△A值与铁(Ⅲ)的质量浓度在0.2~2.0μg·L~(-1)范围内呈线性关系,其检出限(3S/N)为2.3×10~(-2)μg·L~(-1)。按此方法测定了纯水、矿泉水、红酒及啤酒样品中铁量,所得结果与火焰原子吸收光谱法的结果相符,测定值的相对标准偏差(n=6)在0.51%~2.1%之间。  相似文献   

4.
在pH 10.5的B-R(或pH 9.0的氨水-氯化铵)缓冲溶液中,溴化十六烷基三甲胺和氯化十六烷基吡啶能使刚果红与壳聚糖(体系Ⅰ)或刚果红与羧甲基壳聚糖(体系Ⅱ)生成的有色物质产生灵敏的褪色反应,在530 nm波长处,其褪色程度△A与溴化十六烷基三甲胺及氯化十六烷基吡啶用量呈线性关系,溴化十六烷基三甲胺和氯化十六烷基吡啶的质量浓度分别在0.2~3.6 mg·L-1(体系Ⅰ)和0.08~3.2 mg·L-1(体系Ⅱ)范围内呈线性,表观摩尔吸光率εCTMAB=2.08×104L·mol-1·cm-1,εCPC=2.52×104L·mol-1·cm-1(体系Ⅰ);εCTMAB=2.22×104L·mol-1·cm-1,εCPC=2.55×104L·mol-1·cm-1(体系Ⅱ),拟定的方法用于水样中微量阳离子表面活性剂的测定,测得方法的回收率在99.1%~100.8%之间,测定值的相对标准偏差(n=6)在1.2%~3.0%之间.  相似文献   

5.
在稀H_2SO_4介质中及加热85℃的条件下,钌(Ⅲ)对KIO_4氧化亚甲基蓝的褪色反应具有显著的催化作用,建立了一个催化动力学光度法测定痕量钌(Ⅲ)的新分析方法.探讨了该催化反应的最佳实验条件.非催化反应吸光度A_0与催化反应吸光度A之间的差值△A与钌(Ⅲ)质量浓度ρ在0~0.06μg/mL范围内呈良好的线性关系,检出限为2.37×10~(-10)g/mL.测定了动力学参数,反应为准一级反应,表观速率常数为3.63×10~(-4)/s,表观活化能为58.13 kJ/mol.对1.0μg Ru(Ⅲ)测定的相对标准偏差RSD为1.7%(n=11).方法用于分子筛样品中痕量钌(Ⅲ)的测定,回收率98.3%.  相似文献   

6.
试验发现依诺沙星对鲁米诺与铁氰化钾之间的化学发光反应具有显著的增敏作用,而且当依诺沙星浓度在2.0×10-8~2.0×10-5mol·L-1范围内,与相应的化学发光增强信号值(△I)之间呈线性关系,其检出限(3S)为5.7×10-9mol·L-1,取1.0 × 10-6mol·L-1依诺沙星按试验方法测定11次,算得其相对标准偏差为1.75%.结合应用流动注射技术,提出了流动注射-化学发光法(FI-CL)测定药片中依诺沙星的方法,应用此方法分析了3个依诺沙星片剂试样,所测得的结果与其标示值相符.按标准加入法作了回收率试验,所得结果在96.7%~103.0%之间.  相似文献   

7.
腌菜试样用稀磷酸及过氧化氢置于PTFE罐中,在微波炉先后在400 W及500 W消解2 min及4 min,所得试样溶液于100 mL容量瓶中定容供光度测定.在稀磷酸介质中偶氮胂Ⅰ溶液与溴酸钾溶液的氧化褪色反应因亚硝酸根的存在而催化加速.有及没有亚硝酸根存在的两份相同试液的吸光度A及A0之差△A与亚硝酸根质量浓度在50 μg·L-1以内呈线性关系,其检出限为0.82 μg·L-1用此方法分析3件腌菜试样,测定结果的相对标准偏差(n=6)均小于2%.以此样品为基体,加入亚硝酸根标准溶液进行回收试验,测得的回收率在98.0%~102.0%之间.  相似文献   

8.
催化动力学光度法测定水样中痕量硒(Ⅳ)   总被引:1,自引:0,他引:1  
研究了在邻苯二甲酸氢钾一盐酸缓冲溶液(pH 2)中,硒(Ⅳ)对硫化钠还原二甲酚橙的褪色反应具有催化作用.结果表明催化反应是准零级反应,反应的表观速率常数为7.67×10-5mol·L-1·s-1,表观活化能为50.09 kJ·mol-1.催化反应吸光度A.与非催化反应吸光度A的差值△A与硒(Ⅳ)的质量浓度在0.12 mg·L-1以内呈线性关系,方法的检出限为2.66×10-5g·L-1.用于水样中痕量硒(Ⅳ)的测定,结果满意.  相似文献   

9.
用循环伏安法研究了玻碳电极上乙酰二茂铁对亚硫酸盐的电催化氧化行为,试验发现:在中性介质中乙酰二茂铁浓度为6×10-5 mol·L-1时该催化氧化反应的峰电流与亚硫酸盐的浓度在2.0×10-4~2.4×10-3 mol·L-1范围内呈线性关系,回归方程为IPa=4.962×10-3C-0.297,相关系数为0.999 7.将该方法应用于锅炉水中亚硫酸盐的测定,所得结果与碘量法测得的结果相符.测定结果的RSD(n=6)值在0.3%~1.7%之间,回收率试验结果在97.4%~118.2%之间.  相似文献   

10.
在H2SO4介质中及80 ℃的条件下, 钌对KIO4氧化孔雀石绿的褪色反应有明显催化作用, 探讨了反应的最佳条件, 据此建立了催化动力学光度法测定钌的新方法. 非催化反应吸光度A0与催化反应吸光度A之间的差值ΔA与Ru(Ⅲ)质量浓度在0.1~1.5 μg/25 mL范围内具有良好的线性关系, 检出限为4.31×10-10 g/mL. 测定了动力学参数, 反应为准一级反应, 表观速率常数为3.52×10-4 s, 表观活化能为46.97 kJ/mol. 该方法用于分子筛样品及活性炭样品中痕量钌的测定, 其回率在98.6%~104.8%之间, 符合痕量分析的要求.  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.
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   

16.
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   

17.
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   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
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   

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