GB/T 15076.14-2008 Methods for chemical analysis of tantalum and niobium - Determination of oxygen content
Methods for chemical analysis of tantalum and niobium - Determination of oxygen content
1 Scope
This part specifies a method for the determination of oxygen content in tantalum and niobium.
This part is applicable to the determination of oxygen content in tantalum and niobium. The determination range is 0.005%–1.2%.
2 Principle
Under a purified He/Ar atmosphere, the test portion is placed in a high-purity graphite crucible and melted at low-voltage and high current at high temperature, during which the oxygen compounds are reduced and decomposed. The oxygen released from the sample combines with the carbon in the graphite crucible to form a gas mixture of carbon monoxide and carbon dioxide. The carbon monoxide is converted into carbon dioxide using rare earth copper oxide, and the carbon dioxide generated is detected in an infrared cell.
3 Materials
3.1 Helium: With a purity > 99.99%.
3.2 Argon: With a purity > 99.99%.
3.3 High-purity nickel foil or nickel basket: With an oxygen content ≤ 0.002%.
3.4 High-purity graphite crucible.
3.5 Reference materials: Appropriate reference materials, which, in principle, shall have similar chemical composition to that of the analytical sample.
4 Instrument
Pulsed infrared oxygen meter: With a sensitivity ≥ 0.01 μg/g.