1. Analytical Techniques for Trace Levels of Organotin Compounds in the Marine Environment

Organotins still remain a major concern for the safety of the marine environment, and their determination is covered under legislation in quite a number of nations. Because their usage is totally banned, the demand for determining organotins at sub-nanogram concentrations is ever increasing, which is achieved by elimination of matrix interferences, reduction of sample volume, and analyte enrichment. Organotin speciation is a complex technique involving a long and laborious sample treatment procedure that is prone to various uncertainties. To overcome the shortfalls in extraction and pre-treatment, newer microextraction techniques were developed with reduction in sample and solvent volume, extraction time, and enrichment procedures. Moreover, the recent techniques are developed with a major focus on green analytical chemistry to reduce the impact of anthropogenic (laboratory) activities on the environment. Decreasing the detection limit of methods without greatly compromising their sensitivity was a profound topic of environmental research for organotin analysis. In the case of analytical technique, from the late 1970s, the usage of titrometric and spectrophotometric methods were substituted with more sensitive and lower-cost detectors at nanogram level. Furthermore, detection at femtogram levels was achieved by a mass spectrometer coupled to either gas chromatography (GC) or liquid chromatography (LC) systems. One of the significant developments in instrumentation is the application of the isotope dilution technique to detect the transformation/degradation of organotin species during extraction analysis steps. This chapter discusses the methods available for measuring organotins and their metabolites in seawater, sediment, and biota such as fish and oysters and compares the performance of the various analytical methods available.