Seasonal changes in organotin compounds in sediments from the Bahía Blanca Estuary

P. Y. QUINTAS; A. L. OLIVA; A. H. ARIAS; C. E. DOMINI; M. B. ALVAREZ; M. GARRIDO; J. E. MARCOVECCHIO

Environmental Earth Sciences

Springer-Verlag

Lugar: Berlin; Año: 2016 vol. 75 p. 659 - 681

Twenty-four surface sediment samples werecollected in the Bahı´a Blanca Estuary (Argentina) during2013 in order to assess the occurrence of butyltin compounds.Then, six areas ranging from zones with intensivemaritime traffic to other rural/recreational zones at theinner utmost point of the estuary were periodically sampled(3 months) along the whole year. After extraction/derivatizationassisted by ultrasound, three target compounds?including monobutyltin (MBT), dibutyltin (DBT) and tributyltin(TBT)?were analyzed by means of gas chromatography/mass spectrometry (GS/MS). Total butyltin(TBts) levels ranged from 73.5 to 395.2 ng Sn g-1 dry wtTBT was the minor contributor, accounting for 12.6 % ofthe TBts. On the other hand, MBT, for which no baselineprecedents were available, accounted for the 51.4 % ofTBts. Sampling sites could be classified, in terms ofenvironmental health regarding the organotin compounds(OTs) relationship, each from lightly (3?20 ng Sn g-1 drywt) to moderately polluted (20?100 ng Sn g-1 dry wt). Inthe light of TBts levels, distributions and covariation withenvironmental parameters such as granulometry and sedimentorganic carbon the occurrence of DBT and MBTcould not be uniquely attributed to the degradation pathwayof the TBT; in fact, results outlined the possible contributionof some punctual and diffuse sources at the areasuch as refineries, PVC industry inputs and the city hallmain sewage.