1978 Volume 27 Issue 7 Pages 415-419
A new glow discharge chamber is constructed and used as an atom reservoir for atomic absorption spectrometry. The anode of the chamber is positioned at about 0.2 mm from the cathode. After evacuation of the system to about 10-3 Torr by a rotary pump, an operating pressure was maintained by bleeding the high purity Ar. The discharge took place in the abnormal glow region. Cathodic sputtering occurred only on the limited part of the specimen located opposite the cylindrical anode cavity. The following features were observed for a brass specimen (Cu: 59.5%, Zn : 34%): (1) The absorbance of Cu went through a maximum and then decreased with the increase of voltage and current for each Ar pressure; (2) The maximum absorbance increased with the in crease of Ar pressure; (3) The maximum absorbance appeared near the same voltage region for each Ar pressure. However, the maximum shifted to the direction of higher current with the increase of Ar pressure; (4) The sputtering rate measured at 3.3 Torr of Ar increased with the increase of voltage. To assess the performance of the sputtering chamber in practical analysis the relationship between the concentration of Co and absorbance of Co was measured using iron base alloys (The Iron and Steel Institute of Japan). When using this technique in practical analyses dual-wavelength atomic absorption measurements with an appropriate element as an internal standard are desirable.
