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1.
在HCl-NaAc酸性缓冲介质中,曙红Y(EY)与马来酸罗格列酮(ROM)反应形成1∶1的离子缔合物,不仅引起吸收光谱(UV)的变化和EY的荧光猝灭(FS),更能导致共振瑞利散射(RRS)的显著增强,并产生新的RRS光谱。以试剂为参比,吸收光谱的最大褪色波长为510nm;荧光猝灭的激发波长λex和发射波长λem分别为521和544nm;最大共振散射波长λRRS为307nm,并在532nm处形成较强的散射峰。各方法的线性范围分别为4.98×10-7~7.5×10-6 mol/L(UV)、8.34×10-8~1.79×10-5 mol/L(FS)和4.66×10-9~1.25×10-5 mol/L(RRS),检出限分别为1.49×10-7 mol/L(UV)、2.50×10-8 mol/L(FS)和1.40×10-9 mol/L(RRS)。文中研究了吸收、荧光和共振散射的光谱特征、适宜的反应条件及影响因素,并对荧光猝灭机制及RRS的增强进行了讨论,据此建立了灵敏、简便、快速测定抗糖尿病药物马来酸罗格列酮的新方法。  相似文献   

2.
曙红Y分光光度法测定阳离子表面活性剂及其机理研究   总被引:8,自引:0,他引:8  
秦宗会  谭蓉 《分析试验室》2006,25(10):110-114
在弱酸性的HCl-NaAc缓冲介质中,阳离子表面活性剂(CS)与曙红Y(EY)染料反应,形成离子缔合物,溶液颜色发生明显改变,最大褪色波长分别在514 nm(EY-CPB体系)、516 nm(EY-CTAB体系),同时在548 nm(CPB体系)、544 nm(CTAB体系)处有吸收峰,在褪色波长处阳离子表面活性剂的浓度与褪色程度呈良好线性关系,从而建立测定阳离子表面活性剂的光度法。在最大褪色波长处,CPB体系、CTAB体系中CS的浓度在0~4.79×10-5mol/L、0~2.90×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数为2.94×104、2.86×104L.mol-1.cm-1,检出限为8.97×10-7mol/L、7.87×10-7mol/L。若用双波长叠加,表观摩尔吸光系数达5.58×104、5.20×104L.mol-1.cm-1,检出限为5.87×10-7、6.25×10-7mol/L。方法适用于水样中CS的测定。本文还用密度泛函理论对反应机理进行了探讨。  相似文献   

3.
在HCl-NaOAc酸性缓冲介质中,曙红Y(EY)与盐酸吡格列酮(PGH)反应形成1∶1的离子缔合物,不仅引起曙红Y的荧光猝灭(FLU),更能导致共振散射(RRS)的显著增强。荧光猝灭的激发和发射波长分别为λex=524nm和λem=544nm;最大共振散射波长为308nm,并在540nm处产生一共振峰。方法的线性范围分别为9.04×10-7~2.05×10-5mol/L(FLU)和1.6×10-7~5.1×10-6mol/L(RRS),检出限分别为1.88×10-7mol/L(FLU)和4.82×10-8mol/L(RRS)。研究了荧光和共振散射的光谱特征、适宜的反应条件及影响因素,据此建立了灵敏、简便、快速测定抗糖尿病药物盐酸吡格列酮的新方法。  相似文献   

4.
在pH 3.70的B-R缓冲溶液中,盐酸西布曲明与溴酚蓝以摩尔比1比2反应形成具有正吸收和负吸收的离子缔合物,最大正吸收波长为436nm,最大负吸收波长为590nm,线性范围分别在3.4×10-6 mol·L-1(正吸收)、3.8×10-6 mol·L-1(负吸收)以内,表观摩尔吸光率为1.83×105L.mol-1.cm-1(正吸收)、5.51×104L.mol-1.cm-1(负吸收),据此建立了测定盐酸西布曲明含量的分光光度法。方法用于合成样品及尿样中盐酸西布曲明的测定,回收率在96.8%~102.5%,相对标准偏差(n=6)在0.9%~1.7%之间。  相似文献   

5.
本文建立了一种测定克拉霉素的荷移分光光度法,克拉霉素与苯基荧光酮(PF)在乙醇溶液中发生荷移反应,荷移络合物在波长519nm处有最大吸收,其表观摩尔吸光系数为1.70×104 L·mol-1·cm-1,荷移络合物的组成比为1∶1,稳定常数为2.86×104,药物浓度在5.0×10-6~7.0×10-5 mol/L范围内服从比耳定律,当克拉霉素浓度为4.0×10-5 mol/L时,8次测定结果的相对标准偏差(RSD)为0.46%,检出限为6.0×10-7 mol/L。利用该法测定了克拉霉素胶囊中有效成分的含量,回收率大于98%以上。  相似文献   

6.
共振瑞利散射光谱法同时测定α-萘酚和β-萘酚异构体   总被引:4,自引:0,他引:4  
在硼砂-HCI(pH=8.2)的水溶液中,α-萘酚(α-N)和β萘酚(β-N)分别与卢一环糊精(β-CD)形成包合物,对共振瑞利散射光谱(RRS)有很强的增敏作用.实验发现.α-N和β-N两种包合物的RRS光谱在320hm处有等强度的等散射点,β-N的包合物在338nm处出现一个突出尖峰,经偏振实验证实是共振荧光峰,而两者在470nm处的共振瑞利散射峰形和增强趋势一致,且具加和性.故可在470nm处测定萘酚的总量,再在338nm处以"同原射线计量法"测定β-N和α-N的含量.在470nm处测定萘酚总量实验的线性范围为5.0×10-63.6×10-4mol/L,最低检出限为2.0×10-6mol/L,RSD为3.5%.在338nm处测定β-N和α-N含量的线性范围均为5.0×10-6~3.1 X 10-4mol/L,最低检出限分别为1.6×10-6mol/L和1.8×10-6mol/L.RSD分别为3.7%和3.6%.测定的选择性较好,据此可对合成样品进行同时测定和对α-萘酚试剂的纯度分析,结果令人满意.  相似文献   

7.
结晶紫氧化还原褪色光度法测定痕量钯   总被引:1,自引:0,他引:1  
钯(Ⅱ)与结晶紫在亚硝基R盐的存在下可发生氧化还原褪色反应,最大吸收峰位于波长590 nm处.钯浓度在0.2~2.0 mg/L范围内服从比尔定律,回归方程:ΔA=0.455C 0.0032(C为mg/L Pd(Ⅱ)),r=0.9990,相对标准偏差为7.8‰,检出限为9.490×10-5g/L.  相似文献   

8.
秦宗会 《应用化学》2007,24(3):345-348
在弱酸性的HAC-NaAC缓冲介质中,将溴化十六烷基吡啶(CPB)与乙基曙红(EE)染料溶液混合,加入阴离子表面活性剂(AS),溶液颜色加深,最大吸收波长都在516nm处,且阴离子表面活性剂的浓度与溶液的增色程度呈良好线性关系。在最大吸收波长处,3种阴离子表面活性剂——十二烷基苯磺酸钠(SDBS)、十二烷基磺酸钠(SLS)及十二烷基硫酸钠(SDS)的浓度分别在0~2.05×10-5mol/L、0~2.08×10-5mol/L、0~2.04×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数分别为2.38×104、2.82×104和2.98×104L/(mol.cm),检出限分别为8.42×10-7、4.56×10-7和7.95×10-7mol/L。方法具有较高的灵敏度和良好的选择性,用于不同水样中AS的测定,结果满意。  相似文献   

9.
在中性pH值的缓冲溶液中,血红蛋白作催化剂,维生素B6与过氧亚硝酸活性氧(ONOO-)发生反应,维生素B6原来位于391 nm处的强烈的荧光发射峰消失,而在384 nm和424 nm处出现了两个新的荧光峰.据此建立了血红蛋白一维生素B6体系高灵敏检测ONOO-活性氧的新方法.方法的线性范围为5.24×10-8~2.62×10-6mol/L,检出限为2.62×10-9mol/L,对1.31×10-7mol/L的ONOO-溶液测定的相对标准偏差为3.75%(n=7).  相似文献   

10.
阿米卡星诱导金纳米粒子的快速团聚,使其在520 nm处吸收值降低,同时在640 nm附近产生新吸收,且两处吸光度比值(A640/A520)的变化与阿米卡星的浓度呈正比,据此建立了测定阿米卡星的新方法。对p H、反应时间以及纳米金浓度等实验条件进行了优化,在优化实验条件下,测定阿米卡星的线性范围为2.0×10-7~5.0×10-6mol/L,检出限为0.6×10-8mol/L,相对标准偏差(RSD)为1.9%(n=11)。方法用于硫酸阿米卡星注射液的测定,回收率在100.0%~105.0%。  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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