HPLC Determination of 8 Heterocyclic Amines in Fish Products with Solid Phase Extraction

Sample of fish product (2 g) was alkalified with 10 mL of 2.0 mol·L-1 NaOH solution and extracted ultrasonically for 20 min. 50 mL of CH2Cl2 were used to elute the column equipped with 15 g of diatomite. The eluate was passed through a MCX column for SPE separation. Mixture of NH3·H2O-CH3OH (10+90) were to elute the MCX column. The eluate was evaporated to dryness by N2-blowing at 40 ℃, and the residue dissolved in 1.0 mL of CH3OH for HPLC analysis. TOSOH TSK gel ODS-80TM column was used for chromatographic separation, and mixtures of (A) CH3CN and (B) 0.01 mol·L-1 H3PO4 solution pH 3.5 mixed in different volumic ratio were used as mobile phase in gradient elution. PAD were used in the determination. Linear relationships between values of peak area and mass concentration of the 8 heterocyclic amines were kept in the same range of 0.005-1.0 mg·L-1, with detection limits (3S/N) in the range of 0.3-3.8 μg·kg-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 51.8%-93.7%, with RSD′s (n=6) in the range of 0.89%-3.7%.