Low temp. gas chromatog. (LTGC) online coupled with an inductively coupled plasma-mass spectrometry (ICP/MS) was used as anal. device to detect organometallic and -metalloid compds. from river and harbor sediments in West Germany. Different species were volatilized by derivatization with NaBH4 and cryofocused in a trap. Different alkylated species of As, Sn, and Sb were identified, while only methylated compds. of the elements Ge, Se, Te, Hg, and Bi could be detected.