Abstract:

A method for determining nitrate, nitrite and polyphosphates including phosphate, pyrophosphate, triphosphate
and trimetaphosphate in seafood using ion chromatography (IC) was proposed. The stability and contents of these
compounds in seafood were also investigated. The separation was achieved on hydrophilic anion exchange column through
gradient elution using potassium hydroxide as the elutant. The determination coefficients of the developed linear equations
for these analytes were in the range of 0.998 1–0.999 8, and the recoveries of spiked samples ranged from 79.2% to 93.6%
with RSD less than 8.2%. The total content of pyrophosphate, triphosphate and trimetaphosphate was stable within 14 h. This
method has been successfully applied to the determination of pyrophosphate, triphosphate and trimetaphosphate in different
kinds of seafood products from the East China Sea. The results showed that a wide variation in the contents of nitrate, nitrite
and polyphosphates existed among different seafood products, and all residual contents met the national maximum allowable
residue levels except that polyphosphates in one sample were more than 5 g/kg.

Key words: ion chromatography, nitrate, nitrite, polyphosphates, seafood