A drift correction procedure for ICP-AES systems

Abstract

A method is reported for correction of long-term drift in ICP-AES measurements. The change in the intensity of thirty emission lines was monitored over eight hours without recalibration of the instrument. Drift values were found to give errors of up to 20% with respect to the first measurement. The suggested procedure utilises the drift pattern of an intrinsic plasma line, Ar 404.597 nm, and the results of a principal component analysis to remove the drift error. After correction, the drift values drop to less than ±2%.