摘要:

The least squares line correlating Id/Is (the ratio between the signal integral values of the drug to the internal reference standard) and concentration was derived and found linear in the range of 10.0–35.0 mg chloramphenicol and 12.0–28.0 mg streptomycin. Each drug was assayed in combination with its degradation product in a ratio of 33 to 300% for the former and 33 to 200% for the latter. Commercial tablets were also assayed for the two components chloramphenicol and streptomycin existing in a ratio 1:1.

ISSN:0038-7010    

DOI:10.1080/00387018908053875

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

An analytical method is described for the assay of tolmetin, 1-methyl-5-(4-methylbenzoyl)-1H-pyrrole-2-acetic acid, as sodium salt, (Tolectin[rgrave] - 200 mg) using PMR. The protocol reported in this study is simple, precise and yields accurate results of 99.78±0.84 and 100.67±2.08 for the authentic material and capsules respectively. In addition, the PMR spectrum obtained provides a means for qualitative identification of the drug and checking its purity. The principle of the method involves comparison of the integral of the well-defined singlet (positioned at 2.41 Δ) to that of the sharp singlet due -CH3(positioned at 1.91 Δ) of sodium acetate as an internal standard in presence of maleic acid using DMSO-d6solvent. The rationale for the use of maleic acid in the assay procedure has been discussed.

ISSN:0038-7010    

DOI:10.1080/00387018908053876

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The theoretical expression of the first-order factorial moment of a triggered delayed photocount distribution and a description of its SNR have been developed. We explain the adventages of this thecnique, in comparison with the second-order correlation function, when we measured a temporal signal under low light level. We derived the theoretical errors involved in determining a parameter by measuring both functions for a signal with a periodically modulated intensity, since this kind of signals usually appear in spectroscopy. We conclude that the first-order factorial moment of a triggered delayed photocount distribution is a useful tool for characterizing a signal at low; light level conditions.

ISSN:0038-7010    

DOI:10.1080/00387018908053877

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Broadband UV-irradiation of methylacetate isolated in argon matrices causes rather strong modifications to appear in the IR spectrum. Evidence was obtained for a photochemical interconversion of the stable Z-conformer into the less stable E-conformer followed by photolytic decomposition of the latter into stable products. Most of these products could be identified from their IR absorptions. The reverse E→Z interconversion is a thermal process with an activation energy of about 10 kJmole−1. A normal coordinate analysis based on a transferable valence force field obtained from the literature allowed to assign approximate IR frequencies of E-methylacetate.

ISSN:0038-7010    

DOI:10.1080/00387018908053878

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The 383.8 nm band of the GeBr molecule, recorded at high resolution, has been rotationally analyzed. Rotational constants of the upper and lower states have been determined from lines of six, main isotopic molecules of GeBr. The band has been proposed to be assigned as the4σ−−X2π3/20–0 transition.

ISSN:0038-7010    

DOI:10.1080/00387018908053879

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Excited-state ionization equilibria of 6-methyl purine and xanthine were investigated in a wide range of pH.

ISSN:0038-7010    

DOI:10.1080/00387018908053880

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The hydrogen bond formation between 6-methyl purine and cytosine has been studied at room temperature. The absorption and fluorescence emission spectra of 2.10−5μ 6-methyl purine solutions containing different amounts of cytosine in the range of 2.10−4−3, 5.10−4μ were investigated. The association constant for hyrogen bonded complex formation between 6-methyl purine and cytosine was found to be 1, 1.103μ−1from absorption difference spectra. The same association constant in the excited state was found to be 3, 9.103μ−1from fluorescence spectra.

ISSN:0038-7010    

DOI:10.1080/00387018908053881

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

13C and1H NMR parameters were measured for dichloroisoproterenol in solution. Spin-lattice relaxation rates, nuclear Overhauser effects and J couplings were determined and compared to those obtained from isoproterenol. The t rotamer was shown to occur with a much higher probability than the two g rotamers. Dynamics in solution were interpreted in terms of a nearly isotropic motion of an extended molecular backbone. Some interesting differences were given evidence between the ‘preferred’ conformations in solution of dichloroisoproterenol and isoproterenol.

ISSN:0038-7010    

DOI:10.1080/00387018908053882

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A 27.12 MHz low flow (3 1/min), laminar flow, atmospheric pressure neon ICP has been generated. The forward power used is 500 W with a reflected power of less than 5 W. Using higher powers caused the plasma to either extinguish or form numerous filaments. The Hß line is used to determine an electron number density of 8 × 1013cm−3. The N2+(0, 0) and OH(0, 0) transitions did not readily emit. This fact, coupled with the low electron density and low input power, indicates a relatively cool plasma.

ISSN:0038-7010    

DOI:10.1080/00387018908053883

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387018908053874

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor