[Determination of sodium chlorite in processed herring roe by ion chromatography with a conductivity detector]

An analytical method for residual sodium chlorite in several kinds of processed herring roe treated with sodium chlorite was studied. Sodium chlorite was extracted with 9 mmol/L sodium carbonate. After centrifugation, the supernatant was filtered through a 0.2 microm nylon filter. The filtrate was deproteinized by ultrafiltration and chloride ion was removed with an On-Guard Ag cartridge column. The eluate was subjected to conductivity detector-ion chromatography. Recoveries of sodium chlorite from herring roe spiked at the level of 5 mg/kg were 88 +/- 3.7% (n = 5, CV 4.2%). The method had a quantitation limit of 5 mg/kg for processed herring roes.