In shipping, antifouling biocides are employed to prevent algae, mussels or the like from attaching to the ship’s hull. Unfortunately, these biocides cause also harm for organisms that do not settle on underwater surfaces, so-called non-target organisms. For evaluation of a biocide, it is important to clarify the hazard for non-target-organisms. In the case of zinc pyrithione this is a difficult task because it is unstable in solution under light irradiation. It forms several degradation products which interact with each other and with the analytical system when common analytical methods are employed. During analysis, the composition of the analytes can change inadvertently leading to wrong results.
The coupling of capillary electrophoresis with complementary mass spectrometry employed here, however, is characterized by a minimum of interaction between analytes and the analytical system. Thereby, it is possible to determine the identity as well as the concentration of zinc pyrithione degradation products without influences of the analytical method. In a laboratory experiment with commercial antifouling paints, two of these degradation products could be detected. They could be possible indicators for the pollution of water systems with zinc pyrithione because its instability makes it impossible to be detected directly in environmental water samples.
Development of complementary CE-MS methods for speciation analysis of pyrithione-based antifouling agents
Sebastian Faßbender, Ann-Katrin Döring, Björn Meermann
published in Analytical and Bioanalytical Chemistry, 2019, Vol. 411, Issue 27, Pages 7261-7272
BAM, Inorganic Trace Analysis Division