Determination of Residual Chlorite in Vegetables and Eggs Treated with Sodium Chlorite by UV-Ion Chromatography and Effect of Soaking in Water

Abstract

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-PW_XL 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.