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J Hassler

Publications and source records attributed to J Hassler.

4 recordsLinked to original sources
PubMed2001

A long-term validation of the modernised DC-ARC-OES solid-sample method.

The validation procedure based on ISO 17025 standard has been used to study and illustrate both the longterm stability of the calibration process of the DC-ARC solid sample spectrometric method and the main validation criteria of the method. In the calculation of the validation characteristics depending on the linearity(calibration), also the fulfilment of predetermining criteria such as normality and homoscedasticity was checked. In order to decide whether there are any trends in the time-variation of the analytical signal or not, also the Neumann test of trend was applied and evaluated. Finally, a comparison with similar validation data of the ETV-ICP-OES method was carried out.

Journal Article↗
PubMed1996

Direct Spectrochemical Analysis of Solids: A Method for Characterization of Sediments

Techniques for the direct analysis of powdered samples provide an advantageous alternative to methods using wet digestion in sample preparation. The direct spectrochemical methods based on electrothermal vaporization (ETV-ICP-OES, solid-ETV-AAS, etc.) show a great similarity to the classical method of dc arc excitation, used in spectrography. Owing to this, the classical dc arc spectrographical method was used in parallel with ETV methods in the direct solid sampling analysis of river and basin sediments. The calibration procedure is the major difficulty of all techniques applied to direct solid sample analysis because of a lack of suitable reference materials. Consequently, it was necessary to verify the application of model calibration samples, preferentially using the simple dc arc OES system and both spectrographic and spectrometric evaluation. The performance parameters of the methods mentioned are compared with those published for the ETV-ICP-OES and SS-ETV-AAS methods.

Journal Article↗
PubMed1996

Comparison of various calibration techniques for the direct spectroscopical analysis of SiC powders.

Techniques for the direct analysis of powdered advanced ceramics provide an advantageous alternative to methods using wet digestion in sample preparation. The direct spectrochemical methods based on electrothermal vaporization (ETV-ICP-OES, solid-ETV-AAS, etc.) show a great similarity to the classical method of d. c. arc excitation. The calibration procedure is the major difficulty of all techniques applied for direct solid sample analysis, as there is a lack of suitable reference materials of ceramics. Consequently, it was necessary to verify various possibilities of preparation and application of model calibration samples. The results of such a calibration are compared with those using within-laboratory standards.

Journal Article↗