Analysis of Sulfite in Disposable Wooden Chopsticks (SI-35 4D)
Please use this column with suppressor type ion chromatography system.
The concentration of sulfur dioxide or sulfite in a pair of disposable wooden chopsticks was decided ≥4 mg（sulfur dioxide equivalent) in Shoku-An No.1113001 (November 13, 2007) of Department of Food Safety, Pharmaceutical and Food Safety Bureau, MHLW. After preparing disposable wooden chopsticks according to the offial method, sulfite was analyzed using a column for anions analysis, IC SI-35 4D.
Preparation of Sample Pour 25 mL of water into the stoppered test tube (25 mL) and warm it to 95°C. Cut one disposable wooden chopstick into two pieces, soak the peices in heated water (95°C) for 30 minutes, and then remove from the solution. After the solution cooled downm, dilute 5 mL of the cooled solution with 20 mL of water and filter using a 0.45μm membrane filter before injection.