Oral Sessions
- Day 3, May 13（Wed.） 10:25-10:45 Room C (1101/02)
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3C-O12-1025 PDF
Development of a simultaneous quantification method for determination of Cr(Ⅲ) and Cr(Ⅵ) species in leachates of industrial wastes by IC-ICP-MS
Chromium (Cr) exists in two oxidation states of Cr(Ⅲ) and Cr(Ⅵ) in the natural environment. Cr(Ⅲ) is essential for humans, whereas Cr(Ⅵ) is highly toxic even at trace levels due to its strong oxidizablility. Therefore, a method for individual determination of Cr species in environmental samples is required for potential risk assessment. We developed a simultaneous quantification method of Cr(Ⅲ) and Cr(Ⅵ) in liquid samples by ion chromatography coupled with inductively coupled plasma mass spectrometry combined with a chelating pretreatment. 2,6-pyridinedicarboxylic acid (PDCA) was used to unify various chemical forms of Cr(Ⅲ) species to a stable Cr(Ⅲ)-PDCA anion complex, and separated from Cr(Ⅵ) oxyanion by an IC column. For optimization of the analytical condition, we investigated the effect of pH on separation and redox conversion of each species during the chelating pretreatment and chromatography. The optimized pH range of 6.7-7.0 was adopted for Cr speciation analysis of leachates of fly ash samples. From the result, only Cr(Ⅵ) species was detected in the leachates due to precipitation of Cr(Ⅲ) species as Cr(OH)3 under alkaline condition in the leaching experiment.