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Determination of distribution coefficients of polycyclic aromatic nitrogen heterocycles using solid-phase microextraction

The possibility and the efficiency of solid-phase microextraction (SPME) for determination of distribution coefficients of polycyclic aromatic nitrogen heterocycles (PANHs) in aqueous samples are presented in this study. Influence of sample extraction conditions, extraction time, stirring rate, pH, salinity and temperature were tested to optimize extraction efficiency. Three types of fibre sorbent layers, PDMS, PDMS/DVB and PA, were tested and fibre/water distribution coefficients, Kf s , were calculated. The extraction efficiency for PANHs increased in the order PDMS < PA < PDMS/DVB. Values of log Kfs ranged from 0.2 to 2.7 for PDMS, from 0.4 to 3.6 for PA and from 1.4 to 4.4 for PDMS/DVB. The values of log Kfs were correlated with octanol/water distribution coefficients log Kow . The relationship between log Kfs and log Kow shows linear response with regression coefficient in the range of 0.985 and 0.997.