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The preparation of cabbage leaves (CL-1) certified reference material and homogenisation procedures are described and relevant data are compiled. In evaluation of the data four concurrent tests (Dixon's, Grubb's, Nalimov's and the test of coefficient of Kurtosis) for outlier rejection at the significance level 0.05 have been applied. As a result it was possible to establish “certified concentration values” for 10 elements and “reference values” for 4 elements.

A radio-release technique for the determination of traces of elements is described. A small amount of an insoluble compound is fixed on a small disc of filter paper or other suitable material. The exchangeable ions of this compound are labelled with a radioactive isotope and are then replaced with ions of the trace element to be determined in a solution. After the labelled ions are released from the carrier into the solution by shaking, the activity of the species released is measured and compared with one, or, a series of standards processed in the same way. In the first communication, a radio-release method for the determination of mercury, which is applicable to contents > 0.25 μg per ml, in the presence of several other elements including bismuth, lead, thallium, cadmium and copper, is described. The advantages and limitations of this method are discussed.

Statistical scrutiny of over 800 papers published on FIA during the first decade of its existence [1] revealed that 70% of all FIA papers used spectroscopic detection of which 2/3 were based on solution spectrophotometry. Since the fastest growing group of applications was, however, based on use of AA and ICP, the combination of these two spectroscopic techniques with FIA was selected as the topic of this paper.

During recent years the number of scientific papers treating arc excitation sources has rapidly decreased. But there is still a continuing interest in the research of the fundamental properties and application of arc sources. Different scientific contributions treating arc discharge and novel variations of d. c. arc sources used as radiation sources for optical emission spectroscopy are reviewed: theoretical investigations of the arc and its fundamental properties, improvement and development of arc radiation sources, influence of added substances, controlled atmosphere, matrix effects, as well as the analytical applications of the arc.

In this paper a survey is presented of the actual situation with regard to the education in Analytical Chemistry at the universities in the Netherlands.

The most important problems of thermal analysis, including those of methodological nature, are reviewed critically, with regard to the special requirements of analytical chemistry. After touching on the questions of nomenclature and standardisation in thermal analysis, the construction of measuring systems and the connections between the individual parts are dealt with. The nature of information provided by thermal methods of analysis and the present state of development of data acquisition and processing in this field are described. Attention is paid to the problems involved in processing kinetic data and the difficulties of this type of data evaluation are pointed out. A relatively long chapter is devoted to the description of the individual methods, including their fields of application. Thermogravimetry and evolved gas analysis are treated with special regard to systems coupled with MS and GC. Thermomechanometry, thermosonimetry, thermoelectrometry and thermooptometry are also discussed. The paper is concluded by views concerning the future development of thermal analysis.

The possibility of predicting the parameters in HPLC by means of theoretical calculations, represents a significant step forward in the analysis of the complex mixtures of higher boiling petroleum fractions. Quantitative structure-property relationship, QSPR, is being used more and more in Chromatographic studies, since it is by now established that the retention indices have a structural origin. In the present paper we investigate whether the HPLC parameters of alkanes could be predicted from the QSPR-type models using the Wiener number as a structural descriptor. The Wiener number, which has already been applied in several cases to the prediction of gas Chromatographic retention indices and HPLC parameters for polycyclic aromatic hydrocarbons, has now been employed for calculating the HPLC retention time of n-alkanes and cycloalkanes.

The paper presents two different analytical approaches for the determination of Trimorfamid, direct GLC for technical products and combined polarography with subsequent TLC, for the qualitative and quantitative analysis of technical concentrates. Standard deviations are in the range of 0.1–0.2%.

This paper deals with the problem of the dependence of the statistical limit of detection of a fluoride ion-selective electrode on different working conditions (stirring rate, temperature and state of the electrode membrane). The effects of these conditions are studied by experimental design and regression analysis. It is shown that the statistical limit of detection and measurements at low concentrations of fluoride (near to this limit) are substantially influenced by the operational conditions. At higher fluoride concentrations the interference effects (evaluated by sign and significance of regression coefficients) rapidly decrease. The statistical models obtained make it possible to control in a simple way the electrode operation at different working conditions.

Early application of the Zeeman effect to correct for background absorption in atomic absorption analysis is described. This paper also describes the use of this technique for direct analysis of biological samples and the future developments that are expected to occur in this field.

Z. Kafka, L. Vodi~ka, and M. Hajek Laboratory of Synthetic Fuels, Institute of Chemical Technology, CS-16628 Praha 6, CSSR Bestimmung der Stellung der Carbonylgruppe in Triamantanon dureh laC_NMR.Spektroskopie This paper deals with the determination of the carbonyl group position in triamantanone using ~3C-NMR spectroscopy with application of the additivity rule derived from the chemical shifts of diamantane and triamantane. Triamantane is the third member of the diamondoid hydrocarbon series. In triamantane, similarly as in adamantane and diamantane, the secondary position is less reactive than the bridgehead one [1]. Therefore, only tertiary substituted triamantane derivatives were prepared up to this time [2]. We studied the oxidation of triamantane by means of sulphuric acid [3]. The compounds separated from the reaction mixture were supposed to be carbonyl bearing compounds according to the IR spectra. The separation of the reaction mixture yielded the compounds which were studied by IaC-NMR spectroscopy 9 Experimental. Triamantanone (Fig. 1) was prepared by heating triamantane with 96 % sulphuric acid [4]. The product included two isomeric ketones in the ratio 3 : 1 and the main component was concentrated by recrystallisation from hexane. 13C-NMR spectra were measured on the Tesla BS 567 "~ spectrometer at 25.14MHz. A 10-mm tube was used; the II concentration of the compound was 100 rag/1.5 ml CDC13 with .e tetramethylsilane as internal standard 9 Broadband, SFORD and APT spectra were used for the assignment of the signals. The precision of the measurement of the chemical shift was _+ 0.1 ppm. II Results and Discussion 9 The presence of a carbonyl group in the oxidation product of triamantane was verified by IR-spectroscopy (v max. 1,700cm-I); the presence of the