Recently, dried dressed fish fillets have been reported as a cause of food poisoning. Hence, 364 samples of 58 packages of these products
were collected from 9 counties; Keelung, Taipei, Hsinchu, Taichung, Tainan, Kaohsiung, Ilan, Taitung and Penghu in 1998 and their
toxicities and labels were investigated. It was found that over 65% of products had no label listing the product name, manufacturing date,
manufacturer, or food additives. Based on the detecting limit of 5 mouse units per gram (MU/g), the frequency of toxicity occurrence in
the samples collected from Taiwan markets was 1.1%. The highest toxicity was 15 MU/g. The toxin obtained from toxic samples was partially
purified by ultrafiltration and Bio-Gel P-2 column chromatography. Results of analyses by thin-layer chromatography, electrophoresis
and high performance liquid chromatography showed that the toxin was composed of tetrodotoxin and anhydrotetrodotoxin.