Determination Of Trace Elements In High Purity Copper

High purity copper is the raw material of copper certified reference material and copper standard calibration solution. Its purity value is key data for the traceability system of quantity value of chemical measurements. Trace elements have severe effect on the mechanical and physical properties of high purity copper. So it has important significance for analysing accurately the concentration of these trace elements in high purity copper.Glow Discharge Mass Spectrometry(GD-MS) is recognized as one of the best methods of analysing trace elements in high purity metals. GD-MS can analysis most elements in periodic table with low determination limit, fast analysis speed, good sensitivity and accuracy. In this paper, 73 trace elements were determined with the method of GD-MS. Optimal analysis conditions obtained by experiment : The discharge current:45mA, the discharge gas flow:500ml/min, pre-sputtering time:30 min. Samples were measured for 5 times and the relative standard deviation(RSD) were less than 50%. It is indicated that the measurement method could fully satisfy the requirements for the trace analysis in high purity copper. The total content of impurity elements is 1.473 μg/g.Carrier Gas Hot Extraction method(CGHE) is the most popular method for oxygen nitrogen hydrogen carbon sulfur analysis in high purity metals. Oxygen nitrogen hydrogen trace elements in high purity copper were determined using a TCH600 oxygen / nitrogen / hydrogen determinator. Analytical instrumental parameters were optimized: purge time 30 s, outgas time 25 S, outgas power analysis power 4000 W. The limit of quantitative determination(LOD) of the method found were 0.27 μg/g for oxygen, 0.62 μg/g for nitrogen and 0.01 μg/g for hydrogen. And the concentration of nitrogen hydrogen were below the detection levels, the oxygen can determined successfully. Because of the scarcity of available certified reference materials, high pure iron oxide powder was used to calibrate the instrument. The value of oxygen is 2.43 μg/g ± 0.32 μg/g(k=2),and the relative standard deviations(RSD) were no more than 7.7%. The recovery test was performed and the recoveries were between 100%~105%. It is indicated that the measurement method could fully satisfy the requirements for the trace oxygen analysis in high purity copper.Carbon trace elements in high purity copper were determined using a CS844 carbon/sulfur determinator. The ceramic crucible treatment method was bottomed crucible and the quality of flux was 1 g. The limit of quantitative determination(LOD) of the method found were 0.36 μg/g for carbon and 0.78 μg/g for sulfur. And the concentration of carbon sulfur were above the detection levels. Because of the scarcity of available certified reference materials, high pure Ba2CO3 and high pure Ba2SO4 powder were used to calibrate the instrument. The value of carbon was 0.68 μg/g±0.12 μg/g(k=2) and the relative standard deviations(RSD) were no more than 13.8%. The recoveries were between 85%~105%. It is indicated that the measurement method could fully satisfy the requirements for carbon analysis in high purity copper. The recoveries of sulfur were below 60%. Copper and sulfur prone to chemical reactions at high temperature leading to lower analysis.