Analysis of triphenylmethane dyes in seafood products: a review of extraction methods and determination by liquid chromatography coupled to mass spectrometry

Triphenylmethane dyes, such as malachite green (MG), crystal violet (CV) and brilliant green (BG), have been widely used to prevent and treat infections in aquaculture products due to high efficacy, availability and low price. These compounds undergo metabolism towards reduced leucoforms, such as leucomalachite green (LMG), which can also be found in fish. The present review discusses the most relevant extraction methods as well as the main separation and detection techniques used for the determination of triphenylmethane dyes in seafood. Specifically, it is mainly focused on the application of liquid chromatography (LC) coupled with mass spectrometry (MS), including low and high resolution analysers, which are currently applied to identify and quantify dyes in seafood.