Nikola J. Marjanović

Determination of α-tocopherol in Cosmetic Products by Chronopotentiometry

Abstract In the present study, a rapid chronopotentiometric method was developed for the determination of α-tocopherol in various cosmetic products. Determination of α-tocopherol is based on its irreverse oxidation by constant current at the planar glassy carbon electrode. The influence of the most important experimental parameters of chronopotentiometry was investigated. After optimization, an appropriate procedure for the sample preparation was developed. Under the defined experimental conditions, a detection limit of 7.5 mg L−1 of α-tocopherol was obtained. The accuracy of the defined method was confirmed by means of recovery assay. The developed method was successfully applied to quantitation of α-tocopherol in various cosmetic products.

Determination of polycyclic aromatic hydrocarbons in soil by gas chromatography-mass spectrometry

Polycyclic aromatic hydrocarbons (PAHs) were determined in soil samples from forty different locations in Vojvodina. The samples were Soxhlet extracted cleaned-up and analyzed using gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode (SIM). Each PAH was separately quantified using an eight-point calibration of mixed standard solutions in the range between 0.25 and 10 μg/cm3. The sum of the 16 US Environmental Protection Agency PAHs analyzed in the soil samples varied from 0.043 to 1.362 mg/kg of dry soil.