Determination of polyphosphates in aquatic products by alkali liquor extraction-ion chromatography

Established a method for extracting polyphosphates from aquatic products and simultaneously determined pyrophosphate, tripolyphosphate, hexametaphosphate by ion chromatography.Using 3mol/L NaOH as extraction solution could inhibit hydrolysis of polyphosphates effectively, recovery rate was more than 90%.In AS11-HC anionic chromatography column, the separation degree of pyrophosphate, tripolyphosphate, hexametaphosphate were fine.The concentration and peak area exhibited linearity in the range from 1.0～100.0mg/mL.In the condition of optimization of chromatographic, the low determination limits of pyrophosphate, tirpolyphosphate and hexametaphosphate were 3.0mg/kg, 3.0mg/kg and 10.0mg/kg respectively.Using silver carp as blank sample, added three concentrations (1.0, 10.0, 50.0mg/mL) for accuracy and recovery rates tests, the RSD was below 4.0% and the recovery rates were in the range of 95%～100%.