AbstractAnalysis of organotin compounds in environmental matrices is usually performed by chromatographic or spectroscopic techniques. Only a few papers dealing with organotin voltammetric determination have so far been published and this techniques does not seem very promising for organotin speciation. The reasons are likely to be found in the very low organotin concentration levels in the marine environment, in the complexity of environmental matrices and in the presence of several organotin compounds (butyl‐ and phenyltins), together with other metals, in samples; the latter leads to peak overlapping. In this paper we present a study of the influence of tropolone (2‐hydroxycyclohepta‐2,4,6‐trienone) on the voltammetric speciation of butyltin compounds. Results suggest that tropolone, being able to form complexes of different stability with tin and its compounds, improves the applicability of voltammetry to organotin determination by enhancing sensitivity and res