초록
염산 산성(1∼4N) 용액에서 Zr(IV)-XO 착물의 흡광도가 옥살산의 첨가량에 반비례하는 현상을 이용하여 미량의 옥살산을 정량하는 방법을 확립하였다. 말산, 말론산, 말레산, 후마르산, 숙신산, 엽산, 글루타민산은 옥살산량의 100배가 공존하여도 미량의 옥살산을 정량하는 데 방해하지 않지만 타르타르산과 시트르산은 옥살산 보다 많으면 방해한다.
The determination of oxalic acid is carried out with Zr(IV)-XO complex by spectrophotometry. The Mechanism of this method in 1∼4N HCl solution is shown below (XO = xylenol orange); Zr(IV)+XO=Zr(IV)-XO+ excess XO, Zr(IV) - XO + oxalate = Zr(IV)-oxalate + XO When oxalic acid is added to Zr(IV)-XO complex(red color), the absorbance of Zr(IV) - XO complex is decreased in proportional to the amount of oxalic acid. The malic, malonic, maleic, fumaric, succinic, folic and glutamic acid did not interfere even if they are present in hundred times of oxalic acid. If they are present in the same amount as oxalic acid, citric and tartaric acid did not interfere but they are interfere when they are present in much more than that of oxalic acid.