Talanta 46 (1998) 1479–1484 Column preconcentration of organotin with tropolone-immobilized and their determination by electrothermal atomization absorption spectrometry P. Bermejo-Barrera *, G. Gonza ´lez-Campos, M. Ferro ´ n-Novais, A. Bermejo-Barrera Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, Uniersity of Santiago de Compostela, 15706 Santiago de Compostela, Spain Received 23 January 1997; received in revised form 02 June 1997; accepted 22 December 1997 Abstract A method for the determination of total organic tin from marine water samples by electrothermal atomization absorption spectrometry (ETAAS) is described. Samples are previously preconcentrated with a chelating molecule (tropolone) impregnated on a macroporous polymer (Amberlite XAD-2). The graphite furnace programme and preconcentration parameters were optimized. Calibration and addition graphs were performed. Sensitivity obtained with this procedure was 13 ng l -1 . Relative standard deviation was always 10% and analytical recovery were satisfactory, 100%. Some possible interferences were investigated, having no problems with this factor. This procedure allows the distinction between organotin compounds and inorganic tin IV, since the latter is not retained on the column. © 1998 Elsevier Science B.V. All rights reserved. Keywords: Organic tin; Tropolone; Amberlite XAD-2; ETAAS 1. Introduction Interest in the determination of tin and their organic compounds at trace levels in the environ- ment has increased in recent years because of the growing use of organotin compounds over the past 30 years [1–3], due to the great number of industrial applications discovered for these com- pounds. Organotin toxicity is determined by its own nature and by the number of organic groups bonded to tin. It has been found teratogenic and genotoxic effects in some organisms [4,5]. The principal use of TBT was in antifouling paints for ships because they are effective biocides against marine fouling organisms, however, they are non-specific and extremely toxic to non-target animal and plant species. Then, this use was restricted in some countries. The first actions were adopted in France in 1982 [6], followed by UK in 1985 [7,8]. France banned the use of TBT-based paints on boats 25 m length. UK regulation restricted the sale of TBT paints containing more than 7.5% total tin in copolymers or 2.5% total tin as free tin. * Corresponding author. Tel.: +34 981 591079; fax: +34 981 595012; e-mail: qn1956@usc.es 0039-9140/98/$19.00 © 1998 Elsevier Science B.V. All rights reserved. PII S0039-9140(98)00021-6