Abstract
The emission intensities, the signal-to-background ratios (SBR), and the relative standard deviations (RSD) for Cu I 324.75 nm and Cu II 224.70 nm were measured in spark discharge optical emission spectrometry (SD-OES) when the argon plasma was operated under reduced pressures. The SBRs increase with decreasing argon pressures, yielding about 4-times larger values compared to those in the ambient-pressure condition. In these cases, the RSDs are less altered at argon pressures of 10-40 kPa. The reason for this effect is that the background intensities are drastically reduced because the continuum by electron collisions decreases under the reduced-pressure conditions. The reduced-pressure argon plasma would contribute to the improvement in the analytical performance in SD-OES.
