An analytical method for residual sodium chlorite (NaClO2) on vegetables and eggs treated with NaClO2 was studied.
NaClO2 was extracted with water. The extract was cleaned up through as ODS cartridge and was chromatographed on a TSKgel IC-Anion-PWXL PEEK column with 1mmol/L borate buffer as the mobile phase. NaClO2 was detected by a UV detector set as 260nm.
Recoveries of NaClO2 were 90-100% at the level of 0.01g/L spiked in rinsing water from cabbage, carrot, green pepper, Japanese radish, cucumber, potato, lettuce, bean sprout and radish sprout, as well as cut vegetables and hen's eggs. Water-rinsing of vegetables was effective to remove residual NaClO2. The detection limit of NaClO2 in vegetables and eggs was 1mg/kg.
