The determination of bismuth, indium and lead in spiked synthetic and natural sea water by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman-effect background correction was investigated using tungsten containing chemical modifiers and tartaric acid (TA) as a reducing agent. Maximum pyrolysis and optimum atomization temperatures for the analyte elements were determined in the presence and absence of various modifiers. The lowest detection limits of 8.5, 4, and 2.3 mu g l(-1) and characteristic mass Values of 0.07, 0.04 and 0.02 ng for Bi, In and Pb, respectively, were obtained using the W + Pd TA mixed modifier, which was found to be most powerful for the determination of Bi, In and Pb spiked into synthetic and natural sea water. The relative error was decreased from 51 to 0.2% for Bi, from 42 to 2% for In and from 51 to 1.2% for Pb by using the proposed W + Pd + TA modifier mixture. (C) 2000 Elsevier Science B.V. All rights reserved.