Abstract: This study was aimed at establishing a laboratory method for the quantitative detection of tetrodotoxin (TTX). A bioassay was developed by injecting intraperitoneally TTX at various dosages to Kunming strain male mice with body weights of 19－21 g. Results indicated that the 50% lethal dose (LD50) of TTX for Kunming strain mice was 0.18μg. The relationship between TTX dosage and the mean death time of Kunming mice could be expressed as Y = e(0.357/ X +1.005). In addition, a high recovery rate of TTX was achieved by using 0.5% (V/V) acetic acid to extract TTX from globefish, which reached up to 90%. However, the detection limit of the assay for samples was 0.56μg/g. Therefore, Kunming strain mice can be used to quantitatively determine TTX in an accurate, stable and convenient manner, which is promising in the safety control of fishery products.

Key words: tetrodotoxin, 50% lethal dose (LD50), Kunming strain mouse, extraction