摘要：A high-performance liquid chromatographic method using post column reaction system was established for the determination of polyphosphates (PP). Linear polyphosphates with the range of polymerization from 2 to 9 (P2-P9) could be separated on an anion exchange column, TSK GEL DEAE-5PW (Toyo Soda), with 0.01 M HNO3 containing NaNO3 as a mobile phase at flow rate of 1.0 ml/min, with a linear gradient in NaNO3 concentration at one hour intervals. PP were detected as the decrease of absorbance at 500 nm of ferric-sulfosalicylate complex by means of an on-line post column reaction at room temperature, with 0.5 mM FeCl3 containing 2.5 mM sulfosalicylic acid as reaction reagent at flow rate of 0.5 ml/min. The proposed method was applied to the analysis of 30 different commercial products of soft drinks. The pretreatment only necessary after mixing the sample with an equal volume of 0.01 M HNO3 was filtration through 0.45 μm pore size filter. P2-P6 (total 0.231 g/kg) and P2-P4 (0.070 g/kg) were found from 2 kinds of the samples, respectively. The determination limit was 0.02 m mol/kg for all of the PP.
