USE OF TEMPERATURE BUFFERED ARGON ARC IN SPECTROGRAPHIC TRACE ANALYSIS

摘要

A new and widely applicable procedure is described for improving the lower limits of detection of trace elements by emission spectroscopy. A special gas-tight chamber was used that permits the arcing of specimens in a static atmosphere of argon at pressures from 100 to 7500 torr. Observations of the physical features of the argon arc in this pressure range are reported.nThe criterion used to establish the optimum arcing conditions was the measurement of the line-to-background intensity ratios. Experimental parameters were studied to determine conditions for maximizing the elemental line intensities and minimizing the back ground radiation. The sensitive neutral atom lines are enhanced in this system, and the characteristic ion spectra of the argon arc are suppressed by vaporizing a few milligrams of certain metal salts into the discharge with the sample.