疊氮修正希巴辣光度測氧法及其在環境監測上的應用

Azide-Modified Shibala Colorimetric Method for The Determination of Dissolved Oxygen and An Assessment of Its Applicability to Environmental Studies

白書禎(Su-Cheng Pai) ； 郭延瑜(Ting-Yu Kuo) ； 鐘仕偉(Shi-Wei Chung) ； 蘇宗德(Tsong-Teh Su)

《化學》 56卷3期 (1998/09) Pp. 173-185

https://doi.org/10.6623/chem.1998024

摘要

本文介紹一種新發展的光學測溶氧方法，其化學反應原理雖然與傳統的溫可樂碘滴定法(Winkler titration)類似，但以分光光度計取代了滴定步驟而直接在456 nm波長測定。由於本法取樣過程中加了疊氮以遮蔽亞硝酸根離子干擾，測定後再用去碘修正濁度干擾，不僅可用於一般自然水體，也適用於監測排放水及渾濁的樣本。測值的精密度可達0.1%，準確度可達0.5%，均優於美國APHA標準方法中的碘滴定法(421B)及我國環保署公布之標準方法(NIEA 421.54C)。此外，本法及設備也可延伸應用於許多原來用碘滴定原理(iodometry)測定的環境監測項目上。

關鍵字

疊氮修正 ； 希巴辣光度法 ； 溶氧 ； 碘化學

並列摘要

An improved Shibala colorimetric method with azide-modification for the determination of oxygen in natural and waste water is proposed. The chemical reaction during the pickling is similar to that of the traditional Winkler titration, but the detection of liberated iodine was made by direct spectrophotometry at 456nm. Inter ference of nitrite of no more than 200 μM was masked completely by sodium azide. Sample containing sus pended solids was corrected for turbidity after adding excess thiosulphate to de-color liberated iodine . Both precision and accuracy were higher than that could be obtained with the titration by an order of magnitude. The proposed method can also be extended to replace titration procedure in many other measurements involving iodometry.

並列關鍵字

Azide modification ； Shibala colorimetry ； Oxygen ； Iodometry