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1.
研究了在盐酸介质中,V(Ⅴ)-I--十六烷基三甲基溴化铵(CTMAB)离子缔合物的共振散射光谱。实验发现,当有V(Ⅴ)存在时,V(Ⅴ)与过量的I-反应生成I3-,I3-与CTMAB形成离子缔合物微粒(CTMAB+.I3-)n,使I--CTMAB溶液的共振光散射强度显著增加。在波长563nm处,共振散射光强度最大且光散射强度与钒浓度在2~60ng/mL范围内呈正比,据此建立了测定环境样品中痕量钒的共振散射光谱分析新方法,方法检出限为0.66ng/mL。用拟定的方法测定环境样品中微量钒,相对标准偏差小于7.5%,回收率在97.8%~102.4%。  相似文献   

2.
在pH=4.1的HCl溶液中,Bi(Ⅲ)与茜素红和十六烷基三甲基溴化铵(CTMAB)缔合形成粒径较大的疏水性三元离子缔合物(结合比为n(Bi(Ⅲ))∶n(AR)∶n(CTMAB)=1∶3∶3),该反应导致共振光散射显著增强,最大散射峰位于364nm。研究了反应介质、pH值、共振探针浓度等对散射体系的影响,考察了该散射反应的稳定性及共存物质的影响,并对该三元离子缔合物的反应机理进行了探讨。在2.5mL1.0×10-4mol/L茜素红和2.0mL1.0×10-4mol/LCTMAB最优试验条件下,Bi(Ⅲ)质量浓度与共振光散射强度ΔI364nm在0~0.384mg/L范围内呈良好线性关系,检测限为5.898×10-8g/L,对含量为0.18mg/LBi(Ⅲ)溶液进行11次平行测定,其相对标准偏差为2.2%。将该方法用于环境水样中痕量铋(质量浓度为0.552~0.831μg/L)的测定,加标回收率为99.5%~100.2%,测定偏差小于2.7%。基于Bi(Ⅲ)-AR-CTMAB三元离子缔合物的共振光散射光谱,建立了以茜素红染料为光谱探针的痕量Bi(Ⅲ)共振光散射检测新方法。  相似文献   

3.
宋仲容  何家洪  匡海艳  徐强 《应用化学》2010,27(12):1470-1473
在pH=4.1的HCl溶液中,Bi(Ⅲ)与茜素红和十六烷基三甲基溴化铵(CTMAB)缔合形成粒径较大的疏水性三元离子缔合物(结合比为n(Bi(Ⅲ))∶n(AR)∶n(CTMAB)=1∶3∶3),该反应导致共振光散射显著增强,最大散射峰位于364 nm。 研究了反应介质、pH值、共振探针浓度等对散射体系的影响,考察了该散射反应的稳定性及共存物质的影响,并对该三元离子缔合物的反应机理进行了探讨。 在2.5 mL 1.0×10-4 mol/L茜素红和2.0 mL 1.0×10-4 mol/L CTMAB最优试验条件下,Bi(Ⅲ)质量浓度与共振光散射强度ΔI364 nm在0~0.384 mg/L范围内呈良好线性关系,检测限为5.898×10-8 g/L,对含量为0.18 mg/L Bi(Ⅲ)溶液进行11次平行测定,其相对标准偏差为2.2%。 将该方法用于环境水样中痕量铋(质量浓度为0.552~0.831 μg/L)的测定,加标回收率为99.5%~100.2%,测定偏差小于2.7%。 基于Bi(Ⅲ)-AR-CTMAB三元离子缔合物的共振光散射光谱,建立了以茜素红染料为光谱探针的痕量Bi(Ⅲ)共振光散射检测新方法。  相似文献   

4.
在pH3.5的HAc-NaAc缓冲介质中,盐酸二甲双胍(MFH)与Pd(Ⅱ)形成阳离子螯合物,它能进一步与酸性染料曙红Y(EY)的阴离子反应,形成离子缔合物。三元离子缔合物的生成将引起共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)光谱显著增强,其最大散射波长分别位于292、540和327 nm。在一定范围内,三种散射信号的增强(ΔI_(RRS),ΔI_(SOS)和ΔI_(FDS))均与MFH的浓度呈线性关系。方法具有较高的灵敏度,RRS、SOS和FDS法对MFH的检出限(3σ)分别为1.7、13.2和22.7 ng·m L-1。考察了适宜的反应条件和共存物质的影响,结果表明该方法选择性良好。探讨了缔合物生成及散射增强的机理。据此,提出了简便、快速、准确且高灵敏度的测定痕量MFH的光散射新方法,并应用于片剂和尿样中MFH的测定,结果满意。  相似文献   

5.
曙红Y共振光散射探针测定盐酸丙米嗪   总被引:1,自引:1,他引:0  
在弱酸性介质中,盐酸丙米嗪与曙红Y依靠静电引力和疏水作用力形成离子缔合物,使曙红Y溶液的吸收光谱、荧光光谱和共振光散射光谱发生变化。其中以共振光散射法灵敏度最高。据此,建立了使用曙红Y作为共振光散射探针测定盐酸丙米嗪的新方法。研究了体系的吸收光谱、荧光光谱和共振光散射光谱特征。在最大散射峰364 nm处,测得盐酸丙米嗪的线性范围为0.025~2.5μg/mL,检测限为5.32 ng/mL,并将方法用于药物中盐酸丙米嗪含量的测定。  相似文献   

6.
在pH=1.5的HCl介质中,阿苯达唑(ABZ)与12-磷钨酸(TPA)形成摩尔比为3∶1的离子缔合物,从而引起共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)光谱显著增强,其最大散射波长分别位于372nm、726nm和392nm。在一定范围内,三种散射信号的增强(△IRRS、△ISOS和△IFDS)均与ABZ的浓度呈线性关系。方法具有较高的灵敏度,RRS、SOS和FDS法对ABZ的检出限(3σ)分别为1.0ng/mL、3.7ng/mL和2.5ng/mL。考察了适宜的反应条件和共存物质的影响,结果表明该方法选择性良好。据此,提出了简便、快速、准确且高灵敏度的测定痕量ABZ的光散射新方法,并应用于片剂和尿样中ABZ的测定。  相似文献   

7.
在pH=4.5的B-R缓冲溶液中,Fe(Ⅲ)与5-磺基水杨酸配位生成紫红色配合物,使得体系在257nm和342nm处产生2个共振散射峰。在该体系中加入肝素钠后,在静电引力作用下其与配合物结合形成离子缔合物,从而使得体系在257nm和342nm处的共振散射信号减弱。在优化实验条件下,在0.05~15.0μg/mL质量浓度范围内,体系的共振散射信号△I与肝素钠的浓度之间有较好的线性关系(相关系数r=0.9976),其检出限为39.9ng/mL。该方法可直接用于测定肝素钠注射液中肝素钠的含量,回收率为98.9%~102.2%。  相似文献   

8.
在pH为4.1~7.0的Britton-Robinson缓冲溶液中, 甲氨蝶呤与钯(Ⅱ)相互作用形成1∶1的螯合阴离子, 并进一步与亚甲蓝(MB)反应形成1∶1的离子缔合物. 该反应可引起共振瑞利散射(RRS)的显著增强并产生新的RRS光谱, 最大RRS波长位于342 nm. 在一定条件下, 散射增强(ΔI)与甲氨蝶呤的浓度成正比, 其线性范围为0.008~2.0 μg/mL. 此方法具有高灵敏度, 对于甲氨蝶呤的检出限为2 ng/mL. 考察了适宜的反应条件和影响因素, 研究了共存物质的影响, 基于Pd(Ⅱ)-甲氨蝶呤-亚甲蓝体系三元离子缔合物的RRS光谱, 发展了一种高灵敏、简便快速测定甲氨蝶呤的新方法. 此方法用于人血清和尿样中的甲氨蝶呤的测定获得满意的结果. 同时, 对三元离子缔合物的结构和反应机理进行了讨论.  相似文献   

9.
在pH 9.54时,苯唑西林的水解产物与维多利亚蓝B形成紫红色的离子缔合物,使体系的共振瑞利散射(RRS)急剧增强并产生新的RRS光谱,在最大散射波长366 nm处,苯唑西林的浓度在0~6.0μg/mL范围内与散射强度(△IRRS)成良好的线性关系,据此建立了测定苯唑西林的共振瑞利散射法,检出限为0.039μg/mL。该方法可用于苯唑西林药物及人体尿液中苯唑西林含量的测定。  相似文献   

10.
硫酸皮肤素的共振瑞利散射法测定   总被引:2,自引:0,他引:2  
研究了硫酸皮肤素对十六烷基三甲基溴化铵(CTMAB)发生缔合反应的条件、共振瑞利散射特征.结果表明,在pH 5.8的BR缓冲溶液中,硫酸皮肤素能与CTMAB形成离子缔合物,使共振瑞利散射RRS急剧增强并产生新的RRS光谱.硫酸皮肤素浓度在0.04~4.0μg/mL之间与散射强度呈线性关系,方法检出限(3σ)为13 ng/mL,并以CTMAB体系为例研究了共存物质的影响,表明方法选择性好.  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.

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   

13.
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   

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.
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   

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.
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   

19.
20.
黄酮化合物的合成研究进展   总被引:2,自引:0,他引:2  
黄酮化合物是一类具有多种生物活性的天然产物,其经典的合成方法主要为查耳酮路线和β-丙二酮路线.近年来出现了许多新技术、新方法.本文介绍了2'-羟基查尔酮的氧化关环法、黄烷酮氧化法、改进的Baker-Venkataraman法及其他合成黄酮化合物的方法.  相似文献   

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