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An evolved gas analysis method measuring the organic gases and vapours was applied in the investigation of concrete additives. Several commercial superplasticizers and solid cement mortars containing one of them in different concentrations were measured. EGA curves offer some infomlation for the identification of additives, however, the thermal behaviour of the additives in the substantial form and in the mortar is diffcrcnt. The area under the EGA curve and characteristic intensities of the signal may be applied in the quantitative determination of the additives in cement mortars.

Abstract.The technique of diffuse reflectance Fourier transform infrared spectrometry (DRIFT) as an in situ detection method was used for the qualitative and quantitative analysis of drugs (heroin, cocaine and codeine) separated by thin layer chromatography.It was found that at a given interferometer throughput and detector sensitivity the quality of the spectrum depends strongly in the type of the chromatographic thin layer used. A detection limit of approx. 2 gg was attained on a microcrystalline cellulose thin layer with a dynamically aligned Bio-Rad Digilab FTS 60A/896 type interferometer and room temperature DTGS detector. A reliable qualitative analysis can be made with as little as 10 to 15 gg drug per spot.Key words: thin layer chromatography, diffuse reflectance infrared spectrometry, drug analysis.Thin layer chromatogaphy (TLC) is one of the most simple methods commonly used for the separation of non-volatile compounds. Identification of each component that has been separated by TLC, as with all chromatographic techniques, depends on the appropriate selection of standards. Separation methods based solely on the relative retention as well as the traditional detection techniques face the problem of similar chromatographic behaviour. In many cases high performance liquid chromatographic (HPLC) analysis of high molecular weight natural compounds with traditional detection methods causes difficulties in terms of the reliable identification of the components as well. As a consequence, attention has been paid to the use of

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