D.L. Massart’s research while affiliated with Vrije Universiteit Brussel and other places

Limiting ionic conductivities of silver, nitrate and hydrogen ions, and transfer free enthalpy changes for Ag+, H+ ion couples in water - tert. butanol mixtures are reported. The curves that represent the ratio of the Walden products (or the limiting ionic conductivities) on the one hand and the difference of the transfer free enthalpies on the other in function of the solvent composition are also given for the Ag+/H+ pair. In both curves, breaks are observed at 0.05 mole fraction of tert. butanol. This phenomenon is discussed in terms of relative solvation and structuration of the solvent. Comparison is made with dioxane - water systems.

A method for the determination of Cd by AAS in foodstuffs is presented. The determination is carried out after low temperature ashing and extraction with a high molecular weight amine. Of the several extractions investigated, Aliquat 336 3% and Alamine 336 3% in Methylisobutylketone allowed the best results. The former was chosen. The analysis of international standards shows that the method yields accurate results.

Three regression methods, namely least sum of squares, orthogonal regression and least median of squares are applied on data simulating calibration lines and method comparison studies, with and without outliers.

A new non hierarchical clustering procedure is used to evaluate an existing classification of iron meteorites. It is shown that the classification obtained resembles the existing classification to a large degree. This confirms the consistency of both the clustering method and the existing classification. The principal disagreement between the existing classification and the clustering concerns the so-called anomalous meteorites. The reason for this disagreement is discussed.

Abstract An experimental design was used in order to optimize a granulation procedure in a high-shear mixer for a hydrophilic matrix tablet formulation. The parameters tested were the amount of water in the hydroalcoholic granulation liquid, the amount of granulation liquid, and the massing time. The amount of granulation liquid was the most important parameter, followed by the amount of water in the granulation liquid. The influence of the massing time was negligible. A granule with a friability below 20% was obtained.

The environmetrical analysis of the benthic organisms data set from a Black sea region has revealed new information concerning the chemical content and the bioindicating abilities of polychaeta (Melina palmata), Crustacea (Aspendopsis ostroumovi) and molluscs (Mytilus gallo‐provincialis). The application of various multivariate statistical approaches like cluster and principal component analysis, linear regression and partial least square modeling, source apportioning makes it possible to understand in a better way the properties of the benthic organism as collectors of pollutants in a total and a more specific mode. It is shown that heavily polluted coastal zones are indicated in the same way by all benthic species but some specificity could be detected when moderately polluted zones are considered. In this case polychaeta accumulated preferably Co, Cr, Cu and Pb Crustacea ‐ As, Cd and Ni and molluscs ‐ Zn to a limited extent.

In the framework of the Wine Database European Project, 400 wine samples from four different countries, namely Hungary, Romania, Czech Republic and South Africa, were collected and 63 chemical parameters were analyzed in order to determine the possibility to identify the origin of a wine from its chemical content. The ability of multivariate analysis methods such as classification and regression trees and partial least squares discriminant analysis and its uninformative variable elimination variant to achieve this classification task is investigated and a special attention is given to variable selection. The results observed show that it is possible to obtain excellent classification rates based on the chemical content of only few parameters, such as for instance the isotopic ratios or the concentration in trace elements.

Near-infrared (NIR) spectroscopy is a fast and non-destructive analytical technique that offers many advantages for a broad range of industrial applications. In this work, we reviewed recent developments in the pharmaceutical domain where it can be applied from raw material identification to final product release. The characteristics of NIR allow the technique to be implemented as a process analytical technology (PAT). Moreover, recent instrumental developments open the perspectives of numerous applications in the NIR imaging area. After "Introduction", according to their subject, the applications are discussed in the parts "Identification", "Water content", "Assay" and "Other applications".

Direct orthogonal signal correction (DOSC) is applied to correct for major variance sources such as temperature effects, time influences and instrumental differences in near infrared (NIR) data. The samples analysed are creams containing different concentrations of an active drug. The final aim is to classify the samples according to their concentration of active compound. Having performed DOSC on the data, it is not necessary anymore to apply sophisticated chemometric techniques to correct for temperature or time effects and to attribute the samples to their respective concentration classes. Moreover, the application of DOSC on the NIR spectra recorded on two different instruments shows that this method can be considered as a valuable alternative for the standardisation in classification applications. Since the applied algorithm tends to overfit, in a second part of this paper, a comparison is made with an algorithm designed by Westerhuis, which should overcome this problem. Although the calibration set results show that the overfitting has been partially corrected for by the latter algorithm, the test set results did not improve significantly.

Project-based education was introduced in the food and diet course of the Masters program in Pharmacy at the Vrije Universiteit Brussel. The students were divided into groups, each dealing with two projects. One was related to general food science and one to diet products available in public pharmacies. For each project the students prepared a report, an oral presentation and a publication (such as a poster, flyer, article or website) oriented to a broad public. The tutor of each group supervised the activities and evaluated the students both individually and as a team. The students also evaluated their fellow group members. Moderate to high correlations were observed between the evaluations of tutors and students. Over the years it has been observed that the introduction of project-based education improves particular skills of students. Individual evaluation was somewhat problematic, but a suitable methodology was attempted.