The difficult-to-detect toxins come from marine algae growing in warm waters and were identified using high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis.

Scientists at the Okinawa Science and Technology Promotion Center (Uruma, Japan) developed a new test that uses standard laboratory instruments to identify and quantify ciguatoxin. Identification and quantification of 16 toxins were facilitated by the use of 14 reference toxins prepared by either synthesis or isolation from natural sources. Extracts of fish were analyzed using the LC- MS/MS system.

The results of the tests showed distinct regional differences. Ciguatoxin-1B type toxins were found in snappers and groupers from Okinawa, ciguatoxin-3C type toxins were found in a spotted knifejaw, Oplegnathus punctatus, from Miyazaki located 730 km north of Okinawa, and both types of toxins were found in a red snapper. They also identified 12 types of toxin in a marine alga in French Polynesia, which could be the primary toxin source. Extracts from 1–5 g of flesh would sufficiently meet the required detection level of 0.01 parts per billion (ppb) ciguatoxin-1B equivalent for food. The LC-MS/MS analysis was carried out on an Agilent 1200 series LC system coupled to an Agilent 6460 Triple Quadrupole LC/MS (Agilent Technologies, Santa Clara, CA, USA).

About 20,000-60,000 people every year come down with ciguatera poisoning from eating fish tainted with a ciguatoxin, which is the most common source of food poisoning from a natural toxin. Fish, such as red snapper and sea bass, get the toxin by eating smaller fish that feast on marine algae that produce the toxin in tropical and subtropical areas, such as the Gulf Coast of the USA. The current test for the toxin involves a mouse bioassay, where after injection, the mice are observed for debilitating symptoms. The authors concluded that their method outperforms current detection methods and in addition to helping diagnose patients, it will also help scientists study how the toxins move through the food chain from one animal to another. The study was published in October 2011 in the journal Analytical Chemistry.

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Okinawa Science and Technology Promotion Center
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