Razvoj i validacija nove analitičke metode za pripremu uzoraka vode za kvantifikaciju policikličnih aromatičnih ugljovodonika primenom gasne hromatografije - masene spektrometrije

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds whose structure consists of two or more condensed aromatic rings. Due to their toxicity and persistence in the environment, PAHs monitoring is very important especially in water, from where they can through the food chain or directly reach humans. In this doctoral dissertation, a method for the determination of PAHs in water, using gas chromatography - mass spectrometry method was optimized and validated. In the sample preparation technique, dispersive micro-solid phase extraction, new sorbents, prepared by thermal and chemicalthermal modification of natural zeolite, clinoptilolite, were used. After optimization and validation experiments, it was concluded that applying 200 mg of acid-thermal modification (prepared modifying clinoptilolite using 1.5 mol L-1 hydrochloric acid and thermally treated at temperature of 500 oC) enabled achieving the best analytical characteristics. Efficiency values ranged from 69% (dibenzo[a,h]anthracene) to 123% (pyrene). The obtained analytical parameters of the method validation were within the validation criterias. The optimized and validated method was used for analysis of real water samples of the river Nišava and its tributaries in the territory of municipalities Dimitrovgrad, Pirot, Bela Palanka and Niš. Naphthalene, acenaphthylene, acenaphthene and fluorene were present in all samples, and the total concentration of PAHs varied depending on the sampling site, and was in the interval of 6.47 - 33.6 μg L-1, where tributaries contributed to the increase of the total PAHs concentration in Nišava. The obtained individual and total concentrations were higher than the limits prescribed by official regulations and it was concluded that the river Nišava in the territory of Serbia has been contaminated with PAHs, of which light PAHs were predominantly presented in all samples.