Various factors influencing the quality of UVVIS spectra obtained for sea water (in 100 mm cells) have been tested. The spectrophometer instability and baseline drift introduced absorbance error of ~ 0.0002 and ~ 0.001, respectively. Deviations caused by improper blanks reached 0.005 ab-sorbance units. Standard deviation of absorbance values determined for samples collected in the Gulf of Gdansk during repetitive casts (0.008-0.022) significantly exceeded the detection limit based on variability of the blank sample (0.002).
This paper presents the results of measurements of polonium, uranium and plutonium radionu-clides in selected components of the southern Baltic ecosystem, as well as the recognition of their accumulation processes in the trophic chain. Investigation on the 210Po, 239+240Pu concentrations in the Baltic biota revealed that these radionuclides are strongly accumulated by some species. Their mean values of the bioaccumulation factor (BCF)* fell within the range from 9?102 to 2.5?104. The Baltic Sea algae, benthic animals and fish concentrated uranium isotopes only to a small degree, and mean BCF values for this element range from 1 to 55, what is several orders of magnitude lower than for polonium and plutonium. Moreover, it was found that fish constitute an important source of 210Po for human.