Determination of Soluble Barium in Water by Application of Crown Ether (DC18C6)
碩士 === 中國文化大學 === 應用化學研究所 === 95 === Dissolved barium is a geochemical indicator of submarine groundwater in coastal research. Crown ether has very high selectivity for alkali metals (IA) and alkaline earth metals (IIA) to form stable DC18C6M+ and DC18C6M2+ complex ions. Stability constant of format...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2006
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| Online Access: | http://ndltd.ncl.edu.tw/handle/55697178554447172418 |
| Summary: | 碩士 === 中國文化大學 === 應用化學研究所 === 95 === Dissolved barium is a geochemical indicator of submarine groundwater in coastal research.
Crown ether has very high selectivity for alkali metals (IA) and alkaline earth metals (IIA) to form stable DC18C6M+ and DC18C6M2+ complex ions. Stability constant of formation for coordination compounds (DC18C6M2+L) is the highest for Ba2+ then for other IA and IIA metals. Based on characterizations of crown ether and DC18C6Ba2+L, Ba2+ is separated from interference of the large amounts of IA and IIA metals in sea water. Dissolved Ba2+ in coastal waters may be determined by atomic absorption spectrophotometry after liquid-liquid extraction with DC18C6. The optimal conditions of measurement are investigated in this study.
The dissolved Ba2+ in artificial water (SRM 1643D) is 76.2ppb±44％ (certified value 506±8.9ppb) by determination of this method. The average recovery of measurement is only 15％. The barium concentration of Danshui estuarine water at a salinity 31‰ is 36ppb±47％ during spring tide, and 20ppb±81％ at a salinity 26‰ during ebb tide.
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