共查询到20条相似文献,搜索用时 31 毫秒
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The complex of the reagent 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) with Bi(III) has been studied. The composition and stability of this complex have been determined. An analytical method for the spectrophotometric determination of Bi(III) using its complex with 5-Br-PADAP has been developed. Variables influencing the method such as pH, wavelength, and time have been studied. The limitations of this method and the effect of interfering ions have been investigated. Comparison of this method with other methods cited in the literature for the determination of Bi(III) is also included. 相似文献
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Fujita S 《Journal of chemical information and computer sciences》2000,40(1):135-146
A new method for enumerating nonrigid isomers with rotatable ligands has been developed so as to take the symmetries of the ligands into consideration. The method has been based on extended partial cycle indices and has been applied to the enumeration of methyl ether derivatives, tetramethylallene derivatives, and 2,2-dimethylpropane derivatives. These results have been compared with the enumeration results of the corresponding promolecules. The factorization of terms in generating functions has been discussed so that the new method is capable of examining the relationship between promolecules and molecules quantitatively. 相似文献
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J. Szydiowski 《Journal of Radioanalytical and Nuclear Chemistry》1993,173(1):9-16
The theory of the double dilution method is shortly described. Critical volume of the liquid specimen has been determined. Optimal specimen concentration ratios of the sample in a given diluent have been examined. The validity and precision of the method have also been investigated. The usefulness of the method has been confirmed by analyzing a typical coin of Thailand. Good agreement with atomic absorption spectrometry (AAS) is obtained. 相似文献
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Kotaro Ogura Yoichi Fukusima Isao Aomizu 《Journal of Electroanalytical Chemistry》1980,107(2):271-279
A new method for voltammetric determination of the composition of metal complexes has been developed. This method can be used in a manner similar to that of molar ratio except that the voltammetric technique is employed instead of the spectroscopic one. The present technique has been applied to the transition metal complexes with some typical uni-, bi-, ter- and sexidentate ligands, and it was found that the compositions determined by this method were in good agreement with those from the spectroscopic technique. A theoretical approach to this method has been presented. 相似文献
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Six125I labelled polypeptides and proteins were prepared with high specific activity and good quality.The optimal iodination with Iodogen method has been studied and different Radio-HPLC methods for purification have been compared. In addition, the method of coating tube with Iodogen has been improved. 相似文献
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Summary A method to determine free amino acids by pre-column derivatization with phenylisothiocyanate is discussed. The method has been applied to determine free amino acids in wine samples, and the results have been compared with those obtained by means of an automatic orthophthal-aldehyde-9-fluorenylmethyloroformate (OPA-FMOC) method. 相似文献
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R M Riggin C J Shaar G K Dorulla D S Lefeber D J Miner 《Journal of chromatography. A》1988,435(2):307-318
A new high-performance size-exclusion chromatography method has been developed for the determination of potency of human growth hormone products. This method has been extensively validated and shown to correlate well with the hypophysectomized rat bioassay which has been used traditionally. The method is much more precise than the traditional bioassay and thus provides more reliable means of producing consistent biosynthetic human growth hormone batches. 相似文献
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Karlsson R 《Talanta》1975,22(12):989-993
An iodometric method for the determination of ascorbic acid has been devised. The method is based on previously developed coulometric instrumentation. The stability of different ascorbic acid solutions has been studied and the best conditions have been established. Ascorbic acid has been determined in different kinds of samples but with the main interest on pharmaceutical preparations. Speqial regard has also been paid to the other constituents in such samples, with respect to possible interferences. The error of the coulometric method is about 0·1% and the time of an analysis is in the range 2–6 min. 相似文献
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Jain C Morajkar P Schoemaecker C Viskolcz B Fittschen C 《The journal of physical chemistry. A》2011,115(39):10720-10728
Absolute absorption cross sections for selected lines of the OH stretch overtone 2ν(1) of the cis-isomer of nitrous acid HONO have been measured in the range 6623.6-6645.6 cm(-1) using the continuous wave cavity ring-down spectroscopy (cw-CRDS) technique. HONO has been generated by two different, complementary methods: in the first method, HONO has been produced by pulsed photolysis of H(2)O(2)/NO mixture at 248 nm, and in the second method HONO has been produced in a continuous manner by flowing humidified N(2) over 5.2 M HCl and 0.5 M NaNO(2) solutions. Laser photolysis synchronized with the cw-CRDS technique has been used to measure the absorption spectrum of HONO produced in the first method, and a simple cw-CRDS technique has been used in the second method. The first method, very time-consuming, allows for an absolute calibration of the absorption spectrum by comparison with the well-known HO(2) absorption cross section, while the second method is much faster and leads to a better signal-to-noise ratio. The strongest line in this wavelength range has been found at 6642.51 cm(-1) with σ = (5.8 ± 2.2) × 10(-21) cm(2). 相似文献
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基于磁珠的可见光检测微阵列信号的新方法 总被引:1,自引:0,他引:1
以磁珠作为标记物,提出了一种在微阵列上检测核酸的新方法。该法基于生物素同链霉亲和素的亲和作用,利用磁珠的超顺磁性和宏观可见特性,使得杂交结果可在普通的光学显微镜或放大镜下检测,甚至肉眼可见。以合成探针为对照,用参比荧光标记染料Cy3标记方法,对这种新方法的检出限进行了研究,并在此基础上采用大肠杆菌16s rDNA的PCR产物作为样品,进行了细菌检测的尝试,取得了较好的实验结果。本法所得的实验结果易于观测,无需采用大型的荧光检测仪器,因而大大降低了检测成本,与其它可见光检测方法(如金胶银染等)相比,具有方便、快捷的特点。这种新方法在传染病检测和环境监测中将具有广阔的应用前景。 相似文献
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Polavarapu PL 《The journal of physical chemistry. A》2005,109(32):7013-7023
The Kramers-Kronig (KK) transform method for deriving optical rotatory dispersion (ORD) from electronic circular dichroism (ECD) has been analyzed. Three different numerical integration methods for the KK transform have been evaluated, and the method proposed by Ohta and Ishida has been used for further calculations. Using this method, the quantum mechanical predictions of electronic circular dichroism (ECD) have been converted to corresponding ORD and compared with that derived from the linear response method. For three molecules exhibiting monosignate ORD in the nonresonant long wavelength region, the KK transform of ECD associated with the lowest energy electronic transition is found to give ORD values close to those obtained with the linear response method. For molecules exhibiting bisignate ORD in the nonresonant long wavelength region, the KK transform method may not provide the correct results. In the resonant region, the KK transform method provides a computationally economical alternative for predicting ORD. While the KK transform method works much like sum-over-states method for ORD, the former offers convenience in transforming the experimental ECD spectrum without the need for spectral curve fitting. 相似文献
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The Wollak method for the determination of thiosulfate has been investigated. The experimental procedure has been revised in order to eliminate several problems associated with the method. 相似文献
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