ICP-AES line intensity data were fitted to a minimum-curvature smooth curve generated with the aid of a cubic semispline algorithm. These spline-fitted curves were used to obtain linewidth ratios which can provide accurate indication of spectral overlap with the use of only sample and standard spectra.
S. O. Farwell and C. T. Kagel, "Detection of Spectral Overlap Interference in ICP-AES with an Empirical Linewidth Ratio Technique," Appl. Spectrosc. 40, 944-948 (1986)