The combined use of High-performance Liquid Chromatography (HPLC) with mass spectrometric (MS) detection has greatly enhanced the suite methods available for the specific analysis of environmental samples containing organotin compounds. The use of chromatographic separation and mass spectrometric detection provided the specificity needed for tin compounds. Speciation of organotin compounds is important because of the greater toxic effects of tributyltin compared to inorganic tin and other organic forms of the metal. The use of HPLC precludes the need for derivatization in the sample workup. Derivatization has been used widely in organotin analysis, but the procedure has several drawbacks, including incomplete reaction, introduction of additional complexity in an already complex sample, and additional sample workup time. The use ICP-MS or electrospray (or ionspray) MS gives the analyst the sensitivity to investigate environmental samples for organotin compounds at environmentally significant levels.