Tetrodotoxin and Its Analogs: A Review of Analysis Methods and Levels in Pufferfish

Abstract

Pufferfish is a major source of tetrodotoxin (TTX), a potent neurotoxin that can lead to death in humans if consumed. The content of TTX and its analogs in different pufferfish species and the distribution in various fish organs are poorly understood. In this study, we compared TTX analysis methods, including mouse bioassay, enzyme-linked immunosorbent assay, high-pressure liquid chromatography (HPLC) coupled with a fluorescence detector, gas chromatography-mass spectrometry, and liquid chromatography-mass spectrometry (LC-MS) methods. Different HPLC columns (e.g., amide, hydrophilic interaction liquid chromatography, and C18 columns) and mobile phases were compared for TTX analysis using LC-MS. Additionally, published extraction methods were compared for LC-MS analysis. The content of TTX and its analogs in different pufferfish species and their distribution in various organs (e.g., liver, muscle, intestine, testis, ovary, and skin) were summarized. This information can help understand the available TTX analysis methods, variation in TTX contents in pufferfish species from different regions, and TTX distribution in various organs.