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The aim of the thesis is to study the relationship between the structure of N-benzylsalicylthioamide derivatives and their retention behavior in high-pressure liquid chromatography. Furthermore, the influence of various substituents on electron absorption spectra in ultraviolet spectral range was studied. All studied derivatives have two absorption maxima in ultraviolet spectral range at 260 nm and 293 nm. The substitution of an auxochrome on the acyl ring leads to bathrochromic shift and hyperchromic shift, especially of the first absorption maxima. The presence of an auxochrome on the amide ring leads to hyperchromic shift as well. HPLC reversed-phase chromatography, using XDB-C18 ZORBAX column and mobile phase with various composition of acetonitrile, was used to obtain retention times of the derivatives. Using this data, the correlation equations between retention factor (mobile phase with no acetonitrile), resp. slope of the dependence of the logarithm of retention factor on the volume fracture of acetonitrile in mobile phase, and partition coefficient octanol-water, resp. hydrophobic substituent constants, were derived. Key words: QSAR, HPLC, spectrometry, benzylsalicylthioamides

The aim of this bachelor's thesis is to compare chosen analytical methods for the determination of paracetamol in dosage forms. The correctness, the accuracy, financial and time demands were compared. The four methods were chosen: cerimetric titration with visual indication of the equivalence point, VIS and UV spectrophotometry and differential- pulse voltammetry. The amount of paracetamol was determined in four dosage forms: tablets, coated tablets, suppositories, and infusion. The most accurate method was cerimetric titration on the other hand the less accurate was VIS spectrophotometric determination. The obtained results of UV spectrophotometry and differential-pulse voltammetry (in solid dosage forms) were accurate in comparison with the declared value, i.e. permitted range of content of paracetamol permitted by Pharmacopoeia. The minimum time was demanded for the cerimetric titration. Regarding financial demands the most advantageous methods were both VIS and UV spectrophotometry. Key words: paracetamol, cerimetry, VIS and UV spectrophotometry, differential-pulse voltammetry