Study on Impact Basics of Relative Sensitivity Factors of Glow Discharge Mass Spectrometry

Three impact basics of the relative sensitivity factors (RSF) and the ion intensity of glow discharge mass spectrometry (GDMS), including discharge current, voltage and gas flow rate, were investigated. The results showed that under constant discharge current or voltage conditions, the RSF of heavy elements increases while the gas flow rate increases, and the RSF of light elements decreases slightly or stabilizes. Under constant discharge current conditions, the ion intensity increases while the gas flow rate is from 300 mL/min to 400 mL/min, and the ion intensity decreases while the gas flow rate is from 400 mL/min to 500 mL/min. Under constant discharge voltage conditions, the ion intensity increases while the gas flow rate is from 300 mL/min to 500 mL/min. Under constant gas flow rate conditions, the RSF of most elements is stabilized while the discharge current and voltage are changed, and the ion intensity increases while the discharge current and voltage increase. This means that the gas flow rate is the most important impact basic. The RSF of some elements was determined using the CRM of Fe, Co, Ti, Ni, Zn, Sn and Pb under the gas flow rate of 400 mL/min. It was found that the RSF difference of the same element at different matrixes is tiny, and matrix effect isn’t distinct. This helps to achieve accurate measurement using non matrix-matched RSF while the matrix-matched standards are lacking. The mean RSF at different matrixes was calculated to calibrate the measured values of a few elements of two Cu-Zn alloys. The relative difference of the corrected values and the standard values is under 30%.