Determination of nitrite in salted fish by improved ion chromatography

We determined the nitrite in salted fish by an improved ion chromatography method. The samples were first pretreated by AgNO₃ solution to remove most of the Cl^- and the rest of Cl^- was excluded by using the Anpelclean TMIC-Ag column. Then the separation of nitrite was determined by suppressed conductivity detection on Ion Pac AS23 (4 mm×250 mm) analytical column and Ion Pac AG23 (4 mm×50 mm) guard column using 4.5 mmol·L^-1 NaCO₃ and 0.8 mmol·L^-1 NaHCO₃ as elution solvents at a flow rate of 1.0 mL·min^-1. The linear range of this improved method is 0.01~2.00 mg·L^-1 with correlation coefficient (R) of 0.999 9; the detection limit is 0.2 mg·kg^-1and the recovery is 83.0%~101.6%. The method with simple and fast pretreatment can determine nitrite in salted fish products more accurately.