A METHOD OF BACKGROUND CORRECTION FOR DIRECT READING OPTICAL EMISSION SPECTROSCOPIC TRACE ANALYSIS USING OFFSET EXIT SLITS

The problem of monitoring and correcting for background continuum adjacent to analytical spectral lines in optical emission spectrometry is one which has received considerable attention. Background correction measurements are of particular importance in trace analyses by dc arc excitation because of the generally poor absolute intensity precision of the dc arc. In fact, with the normal direct reading optical emission spectrometer which has no background correction system, the detection limits for analytical lines becomes primarily a function of how reproducibly one can maintain the background intensity from one exposure to another. It is not unusual to experience detection limits by direct reading techniques which are three- to ten fold inferior to those obtained by photographic recording. © 1969, American Chemical Society. All rights reserved.