Comparative study of laser-induced breakdown spectroscopy measurement using two slurry circulation systems

Abstract

The experimental conditions associated with slurry measurements to achieve good precision by using laser-induced breakdown spectroscopy (LIBS) are examined. LIBS analysis was applied to a special waste slurry sample that contains 85.4% water, 2.5% ferric oxide Fe(2)O(3), 1.7% alumina Al(2)O(3), and small quantities of oxides of boron and chromium. While liquids add challenge to LIBS measurements, the analysis was successfully performed on iron and aluminum. Two slurry circulation systems were devised to overcome the major technical problems associated with LIBS measurements of slurry samples, namely, sedimentation and change in the lens-to-sample distance during measurement. LIBS slurry measurements using both circulation systems are compared. The results show that the experimental configuration plays a crucial role for online slurry analysis.

Quantitative Analysis of Liquids from Aerosols and Microdrops Using Laser Induced Breakdown Spectroscopy

“…Splashing from direct analysis of liquid surfaces may contribute to the extinction of plasma emissions, thereby resulting in shorter plasma lifetimes. The produced shockwaves increase the shot-to-shot variation, while splashing and the formation of bubbles created inside the liquid may produce quenching and change the characteristics of the plasma, thereby suppressing the LIBS signal . Trying to reconcile these disadvantages, different methods have been proposed, including initiating the plasma within the liquid bulk of the sample to reduce splashing; however, the plasma lifetime was extremely short under these conditions, approximately 1 μs or less .…”

“…The produced shockwaves increase the shot-to-shot variation, while splashing and the formation of bubbles created inside the liquid may produce quenching and change the characteristics of the plasma, thereby suppressing the LIBS signal. 9 Trying to reconcile these disadvantages, different methods have been proposed, including initiating the plasma within the liquid bulk of the sample to reduce splashing; however, the plasma lifetime was extremely short under these conditions, approximately 1 μs or less. 10 Other approaches for minimizing the drawbacks include the use of laminar flows, 10 jets, 11,12 freezing the samples in ice, 13 LIBS within cavitation bubbles, 14 double-pulse plasma generation, 8,15 and converting liquid solutions into a solid matrix.…”

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

“…Oh and co-workers reported an interesting application in which slurries were analyzed using LIBS by application of two circulation systems. 164 The circulation systems employed were originally devised to overcome two of the main problems associated with the analysis of slurry samples, i.e. sedimentation and the change in distance between lens and sample particle.…”