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Histamine, a biogenic amine is a chemical hazard in fish and histamine food poisoning is foundto be associated with high levels consumption of scombroid fish, such as skipjack tuna. The present study tries to investigate the histamine levels in skipjack tuna by using a gravimetric andcolourimetric methods, as simple and rapid methods. Skipjack tuna in the present study wereobtained from three different markets. These methods were validated in terms of accuracy,repeatability, linearity and range of determinations. Linearity of histamine concentrationdeterminations were range from 0.5-300 µg/ml with a correlation coefficient (R
2
) of 0.9997. Therecovery of histamine determination was 81.79% and demonstrated no significant difference between the percentage recoveries obtained at different histamine levels (p < 0.05). Therepeatability of histamine determinations were less than 2% of the Relative Standard Deviation(RSD). These methods were demonstrated the valid histamine determination in skipjack tuna andrelied for routine analysis. Among the tested of skipjack tuna samples 86% were positive forhistamine concentrations. The skipjack tuna samples were significantly different in histamineconcentrations between Peliyagoda fish market, retail fish market and Negombo fish market. Thehigher histamine concentrations were >180 ppm in the skipjack tuna from Negombo. The lowerdefect action level of 50 ppm was observed in skipjack tuna from Peliyagoda fish market(91.6%) and 83% from retail fish market. The higher defect action level was observed in all skipjack tuna samples from Negombo.
