Issue 1, 2014

Determination of lithium in lithium-ionic conductors by laser-enhanced ionization spectrometry with laser ablation

Abstract

Laser-enhanced ionisation (LEI) with laser ablation (LA) into a methane–air flame was used for lithium determination in ferrites. Since there is a lack of certified reference materials matrix-matched to ferrites powders, a set of spinel samples were synthesised by means of aerosol spray pyrolysis (ASP) or by annealing the mixture of Li and Fe(III) nitrates. Characterisation by X-ray diffraction showed that the annealed ceramics contained two phases, such as either α-LiFe5O8 and Fe2O3 or α-LiFeO2 and Fe2O3, while ASP ferrites consisted mainly of α-LiFe5O8. Total lithium content in samples was certified by conventional flame photometry after dissolution. We explained the strong matrix effects on the LA-LEI signal by the discrepancy of surface microstructure (and hardness) due to the difference in the conditions of sample preparation. The optoacoustic signal and emission line of Fe I at 382 nm were recorded simultaneously with the LA-LEI signal in order to compensate for matrix effects. We suggest that the microstructure (ceramics or pellets from spherical microparticles) influences both mass removal (proportional to OA signal) and plasma temperature (proportional to AE signal). Correlation plots between OA and AE signals deviated strongly from sample to sample, which was the basis for the application of a multivariate correction procedure to reduce strong matrix effects. 3D correlation plots (LEI vs. OA + AE) for each sample were built to obtain a new analytical signal, which represented the slope of the correlation line to the plane of the OA + AE signals. This normalised signal was free from matrix effects within a concentration range of 0.6–7.5 Li%. The proposed approach allows the use of ferrites synthesised by the various techniques as reference materials in order to build a unified calibration curve.

Graphical abstract: Determination of lithium in lithium-ionic conductors by laser-enhanced ionization spectrometry with laser ablation

Article information

Article type
Paper
Submitted
02 Jul 2013
Accepted
13 Sep 2013
First published
13 Sep 2013

J. Anal. At. Spectrom., 2014,29, 176-184

Determination of lithium in lithium-ionic conductors by laser-enhanced ionization spectrometry with laser ablation

A. M. Popov, T. A. Labutin, A. E. Goldt, O. V. Usovich, S. E. Bozhenko and N. B. Zorov, J. Anal. At. Spectrom., 2014, 29, 176 DOI: 10.1039/C3JA50218J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements