MICROSECOND-PULSED GLOW-DISCHARGE TIME-OF-FLIGHT MASS-SPECTROMETRY - ANALYTICAL ADVANTAGES

A microsecond-pulsed glow discharge time-of-flight mass spectrometer w as constructed and evaluated for elemental analysis. Mass spectra from the instrument show significant advantages, including higher signal-t o-noise ratios than those of a de glow discharge source. Important tem poral advantages result from the pulsed discharge and pulsed mass anal yser. Mass discrimination among different elements is very small. The instrument currently has a resolving power of 360 in linear mode and 1 600 in reflectron mode (full width at half maximum). Present detection limits are at the low ppm level, limited primarily by the detection a nd data acquisition system. Because the detector is easily saturated, the present data acquisition system has limited dynamic range and sens itivity. Possibilities exist to overcome this constraint.