Determination of 6Li and 7Li abundances by inductively coupled plasma-optical emission spectrometry combined with derivative spectroscopy, multivariate curve resolution and multivariate calibration methods

A rapid and reliable method for the determination of 6Li and 7Li abundances by inductively coupled plasma-optical emission spectrometry coupled with derivative spectroscopy, multivariate curve resolution and multivariate calibration methods is reported. By evaluation of emission lines of lithium, it was found that the resonance line at 670.784 nm provides the greatest isotopic splitting between 6Li and 7Li. After recording the emission spectra in the range of 670.712–670.898, the quantification of 6Li and 7Li abundances was performed with the aid of derivative spectroscopy, MCR-ALS and PLS methods. The performance of the proposed methods was tested by the determination of 6Li and 7Li abundances in synthetic mixtures. The obtained results showed that the proposed approach is suitable for the determination of lithium isotopes.