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Determination of antibiotic residues in southern Baltic Sea sediments using tandem solid-phase extraction and liquid chromatography coupled with tandem mass spectrometry

Siedlewicz G., Borecka M., Białk-Bielińska A., Sikora K., Stepnowski P., Pazdro K.

Oceanologia

2016

No. 58 (3)

221--234

The main objective of this study was to adapt analytical procedures for determining antibiotic residues in solid and aquatic samples to marine sediments and to investigate the occurrence of 9 sulfonamides, trimethoprim and 2 quinolones in southern Baltic Sea sediments. The analytical procedure was applied to sediment samples characterized as sand and silty sand. The validation results showed that a sensitive and efficient method applying tandem solid-phase extraction (SPE) and liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) was obtained. Analytes were determined in the lower ng g−1 range with good accuracy and precision. The proposed analytical procedure was applied to the analysis of 13 sediment samples collected from the Baltic Sea along the Polish coast. Concentrations of antibiotic residues in environmental samples were calculated based on external matrix-matched calibration. Residues of nine out of twelve of the above antibiotics were detected in sediment samples in a concentrations of up to 419.2 ng g−1 d.w. (dry weight). Sulfamethoxazole and sulfachloropyridazine were the most frequently detected compounds (58% of the analyzed samples). The occurrence frequency of trimethoprim was 42% and it was always detected simultaneously with sulfamethoxazole. Preliminary studies on the spatial distribution of the analyzed antibiotics indicate a high level of antibiotics occurring in the Pomeranian Bay and close to the mouths of Polish rivers. The study is the first one to demonstrate the occurrence of antibiotic residues in sediments of the Polish coastal area. The obtained results suggest that sediment can be an important secondary source of antibiotic residues in the marine environment.

Polyphasic characterization of the genus Anabaena from the Gulf of Gdańsk (Southern Baltic Sea). Application of DGGE in taxonomic studies on environmental samples

Siedlewicz G., Forycka K., Surosz W.

Oceanological and Hydrobiological Studies

2012

Vol. 41, No. 3

64-78

The aim of this paper was a taxonomic verification of cyanobacteria of the genus Anabaena that occur in the Gulf of Gdańsk. Classical taxonomic methods were combined with modern molecular taxonomic methods (polyphasic approach). Analysis of the species diversity of cyanobacteria from the genus Anabaena was based on the microscopic analysis and on the analysis of 16S rRNA and ITS region. Comparison of the obtained results with sequences in GenBank showed 97.8-100% similarity for 16S rRNA and 98.8-100% similarity in the case of the ITS fragment. Similarity of the 16S rRNA and ITS sequence of 98.5% seems to be sufficient to determine the species.