A review of pretreatment and analytical methods for triphenylmethane dyes in environmental samples

Triphenylmethane dyes (TPMs) were widely used in aquaculture due to their antibacterial properties; however, their high toxicity, carcinogenicity, and environmental persistence have led to their prohibition in many countries. Nevertheless, their residues continue to be detected in various environmental media. Accurate detection remains challenging due to complex matrix interference and trace-level analysis difficulties, highlighting the urgent need for efficient, sensitive pretreatment techniques and rapid, precise detection methods. This review summarizes recent advances in the analysis of TPMs in environmental samples. It focuses on emerging advanced pretreatment methods-such as liquid-phase microextraction based on deep eutectic solvents and ionic liquids, as well as solid-phase microextraction utilizing metal-organic frameworks and molecularly imprinted polymers-alongside detection techniques including liquid chromatography-mass spectrometry and sensor technology. The review systematically evaluates the advantages of these approaches in improving selectivity, sensitivity, and environmental sustainability, while also discussing current technical limitations and future research directions.