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HPLC [240]. While the method was useful in identifying CTX as the principal toxin in carnivorous fish,
establishing a proper clean-up procedure is difficult due to the extremely low concentration of CTX
required in fish flesh to cause human illness. Furthermore, fluorometric methods have not been reported
for the detection of CTX precursors and several congeners of CTX which lack primary hydroxyls.
Further exploratory efforts are needed in the development of highly sensitive HPLC methods for the
determination of CTXs.

1.2.6.3—
Plant Toxin

Hypoglycin A (HG-A; 2-amino-4,5-methylenehex5-enoic acid) is a water-soluble toxic compound
found in unripe fruits and seeds of ackee (Blighia sapida). The unripe ackee aril (freshly edible
material) contains HG-A at 100-111 mg/100g. When the fruit is ripe, the HG-A levels decrease to less
than 10 mg/100 g. Cooked ripe ackee fruit is non-toxic and has been a staple part of the Jamaican diet
for centuries. The ingestion of unripe ackee fruit products, however, is associated with Jamaican
'vomiting disease'. HG-A, the toxic component of ackee fruit, was identified as the causative agent of
Jamaican vomiting sickness, characterized by repeated vomiting, severe acidosis, and hypoglycemia
accompanied by depletion of liver glycogen. As canned ackee fruit is exported from Jamaica, the
concern does exist that the high levels of HG-A may be present in these products if immature fruit is
packed.

The use of HPLC method for the analysis of HG-A in canned ackee fruit was reported and the method
included 80% ethanol extraction followed by pre-column derivatization in the presence of PITC and
UV detection [241].

1.2.7—
Analysis of Food Contaminants

1.2.7.1—
Amines

Amines in foods are produced by enzymatic degradation associated with fermentation or putrefaction,
and amine levels are shown to be an index of food decomposition. These amines include volatile
amines such as methylamine and trimethylamine, and non-volatile amines such as histamine, putrescine
and spermidine. Mucosa stimulation is a generally accepted physiological activity of amines, but the
amines usually do not cause any danger to people unless large amounts are ingested. However, some of
the amines like spermidine and spermine may be nitrosated in the presence of nitrite and act as
precursors of mutagenic or carcinogenic nitrosamines. Ingestion of large amounts of amines such as
tyramine causes a blood pressure rise and migraine. Histamine is known to be a cause of allergy-like
food poisoning. Some polyamines such as putrescine, speridine and spermine are known to potentiate
hitaminetoxicity and to act synergistically in allergy-like food poisoning. Therefore, determination of
amine content is necessary to control the quality and evaluate the safety of a variety of foods. A number
of methods have been reported for the analysis of amines.

As amines have no prominent functional groups except the amine group, some derivatization is required
for the analysis of amines and its applications are reported. Amines in canned fish were detected by UV
absorption using pre-column derivatization with benzoylchloride [242]. Precolumn technique with
diazonium coupling reagent was used for the determination of histamine in fish with VIS 420 nm
detection [243]. The use of precolumn derivatization with DNS was reported for the analysis of amines
in cheese, fish, wine, soysauce and dried sausage with UV or fluorescent detection (the detection limit

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