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1.
高碘酸盐氧化罗丹明B催化光度法测定钌   总被引:4,自引:0,他引:4  
在0.72mol/L磷酸和90℃水浴条件下,钌催化高碘酸盐氧化罗丹明B(RB),据此建立了高灵敏催化光度测定钌的方法。方法的检出限为8.0×10^-12g/mL,测定范围为0.2~15ng/25mL,对5、10、15ng/25mLRu(Ⅲ)测定的相对标准偏差分别为8.67%,5.94%和1.85%。本反应对Ru(Ⅲ)、RB、KIO4和H3PO4均为一级反应,表观活化能为36.05kJ/mol。13  相似文献   

2.
耐尔蓝-高碘酸钾催化光度法测定痕量钌   总被引:8,自引:0,他引:8  
在磷酸介质和加热条件下,钌(Ⅲ)对高碘酸钾氧化耐尔蓝(NB)有强催化作用,详细研究了动力学条件,建立了动力学光度测定钌的新方法,1g(A0/A)与CRu(Ⅲ)呈线性关系的范围为0.008~1.2ug/L,检出限为0.008rg/L,对0.008和0.8ug/LRu(Ⅲ)测定的RSD分别为14.30%6和1.73(n=11 )。本催化反应对Ru(Ⅲ)、NB和KIO4为一级反应,表观活化能为73.43KJ  相似文献   

3.
钍钼杂多酸-丁基罗丹明B测定岩矿中痕量钍   总被引:2,自引:0,他引:2  
本文报道了一个灵敏度高、选择性好的测定痕量钍的新光度分析法。在聚乙烯醇(PVA)存在下,钍钼杂多酸和丁基罗丹明B(BRB)形成离子缔合物,其适宜条件为cHClO4=1.3mol/L,cMoO42-=6.8×10-4mol/L,cBRB=2.7×10-5mol/L,PVA0.08%。络合物的最大吸收波长为570nm,服从比耳定律范围0~0.8mg/25LTh,表观摩尔吸光度ε为3.63×106L·mol-1·cm-1,测定极限1.8μg/L(n=12),对0.02mg/LTh分析11次的相对标准偏差为2.9%,络合物的摩尔组成Th∶Mo∶BRB=1∶12∶7。大多数常见元素、100倍Ce(Ⅲ)、40倍U(Ⅵ)和20倍P(Ⅴ)不干扰钍的测定。本法已用于地质标样中钍的测定,结果满意。  相似文献   

4.
高碘酸盐氧化亚甲蓝动力学光度法测定痕量锇   总被引:7,自引:0,他引:7  
以Os(Ⅳ)催化高碘酸盐氧化亚甲蓝(MB)反应为基础提出了测定痕量锇的方法。在90℃加热14min和660nm波长处采用固定时间法测定亚甲蓝吸收的降低,锇浓度在0~3.2μg/L范围呈线性关系,检了限为0.02μg/L,对1.6μg/L Os(Ⅳ)测定的RSD为1.56%(n=11),催化反应对Os(Ⅳ)、MB、KIO4和H2SO4均为一级反应,催化反应的表观活化能为87.72KJ/mol,探讨了  相似文献   

5.
丁基罗丹明B-铜钨杂多酸光度法测定微量铜   总被引:3,自引:0,他引:3  
在聚乙烯醇(PVA)存在下,丁基罗丹明B(BRB)与铜钨杂多酸形成离子缔合物。缔合物的形成条件为cH2SO4=1.2mol/L,cWO2-4=6.1×10-5mol/L,cBRB=3.8×10-5mol/L和PVA0.08%。缔合物的最大吸收波长位于570nm,摩尔吸光系数ε=1.66×106L·mol-1·cm-1,铜量在每25mL0~0.5μg范围内服从比耳定律,检测限为每mL0.65ng(n=12),对每mL18ngCu测定的RSD为0.85%(n=10)。缔合物至少稳定150h,其摩尔比为Cu∶W∶BRB=1∶12∶5,红外图谱表明铜钨杂多酸具有Keggin结构。考察了40多种共存离子的影响,大多数常见元素不干扰。本法已用于天然水、自来水、降水、人发、中药和蔬菜中铜的测定,结果满意。  相似文献   

6.
本文采用IO离子选择性电极跟踪钌(Ⅲ)催化IO氧化甲基红反应,实现了动力学法测定痕量钌(Ⅲ)。测定线性范围为5.0×10-11~2.4×10mol L-,检出限为5.0×10-12mo1L-1。方法选择性好、灵敏度高,对载钌的4A分子筛试样中钌含量测定结果满意,相对标准偏差小于8.4%,回收率在96%~104%之间。同时对该反应体系的有关性质也进行了初步研究。  相似文献   

7.
张光  张林林 《分析化学》1997,25(1):79-81
报道以5-(5-硝基-2-吡啶偶氮)-2,4-二氨基甲苯(5-NO2-PADAT_作为测定钌的分光光度法。在40%乙醇存在下PH4.0-6.5乙酸-乙酸钠缓冲溶液中5-NO2-PADAT与Ru(Ⅱ)形成稳定的红色络合物。该络合物的无机酸作用下,可转变为另一型人有较高吸收特性的络合物,适宜酸度范围分别为0.12-2.0mol/LHCl,0.12-1.2mol/LHClO4,0.12-1.0mol/L  相似文献   

8.
本文报道一个光度法测定纳克量锡的新方法。在聚乙烯醇(PVA)存在下锡(Ⅳ)与钨酸盐和耐尔蓝(NB)反应形成离子缔合物,离子缔合物的最大吸收位于580nm,表观摩尔吸光系数ε值2.95×107L·mo1-1·cm-1,服从比耳定律范围0~2.0μg/L,检出限(3σ)0.083μg/L(n=10),对2.0μg/L锡测定的RSD为1.42%(n=11),离子缔合物至少稳定72h。考察了40多种共存离子的影响,大多数常见元素不干扰。测定锡的适宜条件[H2SO4]=1.20mo1/L,[WO2-4]=6.05×10-5mo1/L,[NB]=5.5×10-5mo1/L和PVA0.08%。本法已用于某些合金钢和锌合金中纳克量锡的测定,结果与推荐值吻合,回收率满意。  相似文献   

9.
砷锑钼三元杂多酸光化学分光光度法是测定0 .04 ~1 .0 m g/ L 砷的新方法。在0 .12 mol/ L H2 S O42 .0 ×10 - 4 m ol/ L Sb( Ⅲ)2 .0 ×- 3 m ol/ L Mo( Ⅵ)4 % ( V/ V) 甲醇介质中, As( Ⅲ) 、 Sb( Ⅲ) 、 Mo( Ⅵ) 形成的三元杂多酸被紫外光还原生成三元杂多蓝(λm a x = 780 nm ) 。实验结果表明,方法具有灵敏度高,选择性好,操作简便等特点。  相似文献   

10.
本文报导了以玻碳电极为基体的1:12硅钼杂多阴离子薄膜化学修铈电极的制备及其电化学特性。并应用于导数伏安法测定。在4.0×10 ̄(-3)m0l/L(NH_4)_6MO_7O_(24)-6.8×10 ̄(-2)mol/LNa_3Cit-0.48mol/LNHO_3体系中,硅浓度在8.3×10 ̄(-7)~1.7×10 ̄(-3)mol/L范围内与峰电流呈良好线性关系,检测限为8.0×10 ̄(-7)mol/L。对可溶性硅(以SiO_2计)为245.05mg/L的黑液,稀释10倍后,取2.00mL平行测定9次,RSD为0.58%,加标回收率在97.3%~104.4%间。  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.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

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