Ultrasound-assisted dispersive liquid-liquid microextraction combined with high performance liquid chromatography for sensitive determination of five biogenic amines in fermented fish samples

Ultrasound-assisted dispersive liquid-liquid microextraction (USADLLME) coupled to high performance liquid chromatography with fluorescence detection was developed for the simultaneous determination of five biogenic amines (histamine, tryptamine, cadaverine, tyramine and spermidine). The biogenic amines were derivatized with 9-fluorenylmethyl chloroformate before analysis. The five biogenic compounds were separated within 30 min using a C18 column and gradient elution with acetonitrile and 1% acetic acid. The parameters affecting extraction efficiency by USADLLME such as type and volume of extraction solvent and disperser were studied. Under the optimum conditions for USADLLME, 200 mu L of 1-octanol as extraction solvent, 200 mu L acetonitrile as disperser with the aid of ultrasonication for 1 min, resulted in enrichment factors in the range of 12-42. Good linearity was obtained from 0.2-300 ng mL(-1) (r(2) > 0.992). Limits of detection ranged from 0.02 to 0.5 ng mL(-1). The proposed method was applied in the analysis of biogenic amines in fermented fish samples, good recoveries were obtained in the range of 77.02-126.38%.