Quantification of Tralopyril by LC-MS/MS

Tralopyril is a synthetic organohalogen compound with the molecular formula C₁₂H₅BrClF₃N₂ and a molar mass of 349.53 g/mol. Its structure includes bromine, chlorine, nitrogen, and fluorine atoms, making it part of the pyrrole chemical class, characterized by a five-membered ring containing nitrogen. Tralopyril results from the N-dealkylation of the ethoxymethyl group in chlorfenapyr, an insecticidal precursor. It is widely used as an antifouling agent to prevent biofouling on ships, marine structures, and aquaculture equipment. This action helps maintain vessel efficiency, reducing drag and fuel consumption, and controls biofilm formation on submerged surfaces.

While tralopyril is effective in marine applications, it raises environmental concerns due to its toxicity to aquatic organisms. It is stable and resistant to rapid degradation, which allows it to persist in marine environments, accumulating in sediments and potentially bioaccumulating in marine organisms. Studies show that it can impact non-target species, such as fish and invertebrates, at low concentrations, with effects on reproduction, growth, and survival. This persistence and potential toxicity have raised regulatory concerns, prompting environmental monitoring to assess tralopyril's impact on marine ecosystems and the food chain.

Environmental monitoring of tralopyril typically involves advanced LC-MS/MS analysis, due to the method's sensitivity, selectivity, and capacity for quantifying low concentrations. LC-MS/MS is used to detect tralopyril and its degradation products across various environmental matrices, including seawater, fish, and sediments. Sample preparation is critical and often includes specific extraction techniques to handle different matrices; for example, solid-phase extraction (SPE) or liquid-liquid extraction (LLE) is used to concentrate and purify tralopyril from complex samples like fish tissues and sediments. This preparation removes matrix interferences, enhancing sensitivity and accuracy.

In seawater, LC-MS/MS can accurately measure trace levels of tralopyril, providing crucial data on its distribution and persistence in aquatic ecosystems. Sediment samples require rigorous extraction processes, given that sediments act as long-term reservoirs for tralopyril, and testing these samples aids in understanding potential bioavailability over time. In fish, analysis helps assess bioaccumulation and the potential risk to organisms higher in the food chain, including humans.

The data from LC-MS/MS analyses enable regulators and researchers to better understand the environmental fate and toxicological impact of tralopyril, supporting risk assessments and informing policies to protect marine life and ecosystems from persistent antifouling chemicals.