LIBS (Laser-Induced Breakdown Spectroscopy) EA-300

The EA 300 Series Laser-based Elemental Analyzer from Keyence uses laser-induced breakdown spectroscopy (LIBS) for elemental analysis. 

The main applications of LIBS are:

• Identification of Materials
• Quantitative elemental analysis
• Identification of impurities
• Detection of elements from H to U (see figure below)

Some characteristics of the instrument:

• No sample preparation is needed
• Fast measurements (a few seconds)
• Capable of mapping (~10 µm resolution, depending on the sample material)
• Capable of depth profile analysis (~10 µm resolution, depending on the sample material)
• It is a class I laser product (no PPE needed)
• Laser wavelength: 355 nm
• Spot size: 10 µm (typical)
• Image magnification: 20x to 200x (low mag camera) and 300x to 1000x (LIBS camera)
• Maximum sample size: 250 mm x 250 mm x 30 mm
• Scannable area: 40 mm x 40 mm
• Maximum sample weight: 1 Kg
• Samples suitable for analysis: bulk, solid, liquid, powder, films, gel

How does LIBS work?*

The main physical process that forms the essence of LIBS technology is the formation of high-temperature plasma, induced by a short laser pulse. When the short-pulse laser beam is focused onto the sample surface, a small volume of the sample mass is ablated (i.e. removed via both thermal and non-thermal mechanisms) in a process known as Laser Ablation. This ablated mass further interacts with a trailing portion of the laser pulse to form a highly energetic plasma that contains free electronics, excited atoms and ions. Many fundamental research projects have shown that the plasma temperature can exceed 30,000K in its early life time phase [1].

When the laser pulse terminates, the plasma starts to cool. During the plasma cooling process, the electrons of the atoms and ions at the excited electronic states fall down into natural ground states, causing the plasma to emit light with discrete spectral peaks. The emitted light from the plasma is collected and coupled with an ICCD/spectrograph detector module for LIBS spectral analysis. Each element in the periodic table is associated with unique LIBS spectral peaks. By identifying different peaks for the analyzed samples, its chemical composition can be rapidly determined. Often, information on LIBS peak intensities can be used to quantify the concentration of trace and major elements in the sample.

With the advancement of powerful chemometric software for LIBS data analysis, and with steady progress in understanding laser ablation fundamentals, today’s analytical researchers are applying LIBS effectively for both quantitative and material discriminatory analysis for a wide range of sample matrices.

[1] R.E. Russo, X.L. Mao, H.C. Liu, J.H. Yoo, S.S. Mao: Appl. Phys. A 69 [Suppl.], S887–S894 (1999)

* from Applied Spectra

Detection limits:

Source: Libs-info