摘要:

Techniques for signal to noise ratio enhancement (filtering) of noisy experimental data are compared by comprehensive computer simulation using synthetic data. The four important descriptors: signal to noise ratio enhancement, peak width increase, peak maximum displacement, and computation time on a laboratory minicomputer are determined for each filter type studied. Comparative results indicate important trends and considerations of signal processing as well as providing a foundation for the selection of filter designs for a given instrumental situation.

ISSN:0003-2719    

DOI:10.1080/00032717908059751

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The environmental effects of coal mining on the chemical composition of Trout Creek in Colorado are investigated using Individualized Differences Scaling and Canonical Correlation Analysis. Individualized Differences Scaling shows superiority over Canonical Correlation in the analysis of several matrices of measurements when the hypothesis of commonality of chemistry between each matrix cannot be justified a priori.

ISSN:0003-2719    

DOI:10.1080/00032717908059752

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Two different sets of data have been subjected to distortion by induced systematic errors of types that are common in analytical chemistry. By means of eigenvector projections and a disjoint principal components analysis it is demonstrated that even gross systematic errors do not significantly influence the classification of the samples.

ISSN:0003-2719    

DOI:10.1080/00032717908059753

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A kinetic study of the iron(II)-induced perbromate-lactic acid reaction was carried out with a perbromate-selective electrode to monitor the course of the reaction. Reaction rate and equilibrium constants are reported. A potentiometric method is described for the determination of 90–680 μg of lactic acid with relative errors and standard deviations of 1–2 %.

ISSN:0003-2719    

DOI:10.1080/00032717908059754

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The oxidation of the 1, 2, 3, 4-thiatriazol-5-thiolate ion CS2N−3by, permanganate ions in an alkaline medium was investigated. The pseudo-halide undergoes a quantitative seventeen-electron change reaction yielding sulphate, nitrogen and carbon dioxide as final products. Despite the similar chemical behavior exhibited by thiocyanate and CS2N−3ions the experimental data strongly suggested that the oxidation reactions of the pseudo-halides dealt with in this study do not follow the same mechanism. On the basis of this reaction an oxidative analytical method was developed for the CS2N−3. The pseudo-halide is oxidized by an excess of permanganate ions. The remaining oxidant is titrated with standardized thalium (I) or hexacyanoferrate (II) solutions. Considerable improvements over former procedures were achieved employing two polarized platinum electrodes to detect the end point, by potentiometry. The method proposed here is simple, precise, accurate, rapid and allows the determination of pseudo-halide concentrations down to 1 × 10−3M.

ISSN:0003-2719    

DOI:10.1080/00032717908059755

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The formal potential of Ag [222] /Ag(s) system is supposed to be independent of the solvent, taking in account the [222] ligand structure and the corresponding cryptate. This extrathermodynamic hypothesis is confronted to the one usually considered, water, methanol, D. M. S. O., acetonitrile and tetramethylurea being the used solvents. It seems possible to generalize this hypothesis to other cations and cryptands. The stability constants of cryptate [222] of the evaluation of pKAg[222]+constants, Nernst's law being respected. The argentometric titration of ligand [222] in presence of Na+, Li+, Tl+, Cd2+, Ni2+ions allows to evaluate the pKof corresponding cryptates in D. M. S. O. and methanol. Tl [222]+/Tl system follows Nernst's law in methanol and D. M. S. O. The dissociation constants have been evaluated from polarographic measurements in acetonitrile. The electrochemical systems are not rigorously fast, which does not allow an accurate determination of those constants by that method. Still it gives an order of magnitude.

ISSN:0003-2719    

DOI:10.1080/00032717908059756

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The present paper deals with the TLC separation of some closely related 2-aroyl-3-arylbenzo- and naphtho [2, l-b] furans. In view of the estrogenic activity associated with 2-aroyl-3-alkyl-benzofurans1and the antiimplantation activity of 2, 3-diphenyl-benzo- and naphtho [2, 1-b] furans2, 2-aroyl-3-arylbenzo- and naphtho [2, 1-b] furan derivatives have been synthesized as possible estrogenic compounds3.

ISSN:0003-2719    

DOI:10.1080/00032717908059757

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Organic compounds leached from paper and glass soxhlet thimbles have been identified by computerized high resolution gas chromatography /mass spectrometry. Nineteen specific organics have been tentatively identified from paper thimbles. The analysis of glass thimbles have not demonstrated these contaminants. The use of glass thimbles as a substitute for paper is advantageous in preparation of samples for trace organic analysis. This is an improvement but not a panacea as cross-contamination must still be evaluated by the analytical chemist.

ISSN:0003-2719    

DOI:10.1080/00032717908059758

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The quantitative analysis of sulfur by combined gas chromatography-mass spectrometry (GC-MS) can be effected using34S-enriched sulfur as an internal standard.

ISSN:0003-2719    

DOI:10.1080/00032717908059759

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A means of separating gaseous sulfuric acid from flue gas particles has been evaluated. Previous attempts to achieve this separation by filtration resulted in retention of the acid by the particulate buildup on the filter surface. By conducting a laboratory study of a prototype electrostatic precipitator, followed by actual flue gas sampling, it was found that the precipitator may eliminate the need for a filter without affecting the measurement results. It was also found that the precipitator could be used prior to a prototype acid monitor for the successful continual monitoring of H2S04in combustion gases.

ISSN:0003-2719    

DOI:10.1080/00032717908059760

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor