Caffeine (1,3,7-trimethylxanthine) is an alkaloid that acts as a stimulant on the central nervous system. Caffeine consumption brings a momentary increase in awareness and alertness in humans, as well as in experimental animals. The refluxing method and the regular coffee preparation method were used to extract caffeine from several coffee varieties that were sold in Bosnia. TLC and melting point analysis were performed before and after purification using vacuum sublimation. Chemical characterization of samples by FTIR (Fourier Transform Infrared Spectroscopy) analysis was performed by comparing with caffeine standard spectra. The percentage of extracted impure caffeine was higher in coffee samples obtained by the ordinary brewing method compared to reflux. After purification of crude extracts, all refluxed samples yielded more caffeine than those prepared by conventional brewing. In developed TLC chromatograms, Rf values of samples and standard match the literary Rf values of caffeine. Unprocessed caffeine samples showed a melting point from 185 to 216°C, corresponding to the range of 180 to 220°C, the melting point of crude caffeine. After vacuum sublimation, the melting point of all samples was between 235 and 237 °C, which corresponds to the literary values (235-239 °C for the “Merck” caffeine standard). Comparing the FTIR spectra of samples and standard, characteristic caffeine signals were observed confirming successful caffeine isolation. The caffeine content in the analyzed coffee samples from the Bosnia and Herzegovina market complies with FDA (Food and Drug Administration) regulations on the daily amount of caffeine intake per cup of coffee.

This study aimed to develop a rapid method for separation of stigmasterol, campesterol and β-sitosterol in Prunus spinosa L. (sloe) fruit extracts by High Performance Liquid Chromatography system. Samples were prepared by Soxhlet extraction method and separated on a high strength silica C18 column using acetonitrile-methanol mobile phase and Photodiode Array Detector. The optimized method resulted in a linear calibration curve ranging from 1.7 ng mL-1 to 130 ng mL-1 for all three phytosterols. Analyses of internal and external phytosterol standards showed good linearity (R2 of 0.998 to 0.999); LOD and LOQ were determined to be 2.33×10-7-2.18×10-4 and 7.07×10-7-6.60×10-4 mg mL-1, respectively. Repeatability and reproducibility precision analyses showed acceptable values of RSD %. β-sitosterol was the predominant phytosterol (51.53-81.03 % of total) among all samples. Method validation parameters indicated that this analytical method can be applied for accurate and precise determination of campesterol, stigmasterol and β-sitosterol, in selected extracts.

: The samples of Clinopodium nepeta (L.) Kuntze (Lamiaceae) aerial parts were collected from four different localities in sub-Mediterranean area of Bosnia and Herzegovina and subjected to phytochemical profiling. Shade-dried and fresh samples were used to determine their headspace volatile organic composition by solid-phase microextraction on two differently coated fibers. Corresponding essential oils were obtained by hydrodistillation. Both headspace and essential oil were analysed by gas chromatography-mass spectrometry Among detected compounds, piperitenone oxide and pulegone were dominant in the headspace of shade-dried and fresh C. nepeta samples. The essential oils contained 42 compounds including pulegone (44.8%), piperitenone (48.8%) and piperitenone oxide (60.2%) as the major compounds, followed by limonene, cis piperitone oxide, p -menthone and dihydrocarvyl acetate. In this work, a wide range of volatile compounds present in C. nepeta samples from Bosnia and Herzegovina was determined. The obtained data provides detail phytochemical analysis of the volatiles of C. nepeta and therefore completes earlier researches of this plant from the other geographical areas.

Magnesium is an essential element and the intracellular divalent cation involved in many biochemical functions. People with magnesium deficiency must increase their intake of magnesium, usually in the form of various supplements. A common form of magnesium supplement widely available in pharmacies is magnesium oxide (MgO). In this work, the content of MgO was determined in pharmaceutical supplementations using spectrophotometry, based on the reaction between magnesium ions and eriochrome black T at a wavelength of 535 nm. The analysed content of MgO ranged from 360.5 to 386.5 mg MgO, which corresponds to the daily Mg recommended values (300 to 400 mg).