Estimation of Oxalic Acid in Drinks

The levels of oxalic acid in commercially obtainable drinks were estimated using ion chromatography. Variability of oxalic acid contents in many drinks was observed. Large amounts of oxalic acid were contained in Maccha. That amount was about 6 times that in green tea. The difference of oxalic acid contents in tea by infusion time was examined. The maximum concentration of oxalic acid in distilled water was reached in 4 minutes. Oxalic acid concentration by water used for infusion, distilled water and tap water, were compared. The difference in the two results can be regarded as significant. There was a significant difference in the oxalic acid concentration in distilled water and in tap water (p＜0.05)