1994 Volume 10 Issue 6 Pages 895-899
The effects of the discharge-gas flow rate on ion signals at a constant discharge voltage and current were studied with a Grimm-type glow-discharge ion source attached to a commercial mass spectrometer for inductively coupled plasma mass spectrometry. The ion signals as well as the relative sensitivity factors (RSFs) varied with the gas flow rate to different degrees for different elements and sample materials. The RSF of Cr+ in a titanium-base alloy, for example, increased by about four fold along with an increase in the gas flow rate from 4 to 16ml/min. The increase of the gas flow rate did not cause an enhancement of the sputtering rate of the samples, the variation of the ion kinetic energies nor the variation of the atomic emission intensities. Although the reason for the variation of the RSFs with the gas flow rate was not clear, the gas flow rate was found to be an important discharge parameter in glow-discharge mass spectrometry.