Elemental analysis of limestone by laser-induced breakdown spectroscopy, scanning electron microscopy coupled with energy dispersive x-ray spectroscopy and electron probe microanalysis

Abstract

Limestone, a sedimentary rock-forming mineral is a source of lime and is important industrially as it usually contains +95% calcium carbonate and <5% impurities. The presence of these impurities can cause problems while accessing the different applications of limestone requiring high chemical purity. Due to its great significance and multiple applications, the qualitative and quantitative analysis of limestone is highly desirable. The analysis of the emission spectrum obtained at the fundamental harmonic (1064 nm) of Q-switched Nd:YAG laser revealed the presence of Ca, Si, Al, Mg, Na, Fe, Ti, K, Sr and S with varying intensities. The Boltzmann plot method used to deduce the excitation temperature, and the electron number density value measured by the Stark broadening method resulted in the ranges from 4091-4231 K and (1.2-6.4) × 10 16 cm −3 , respectively. The quantitative analysis has been performed using the calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique based on the assumption of local thermodynamic equilibrium and optically thin plasma. The results of the CF-LIBS technique were compared to the measurements of other more standard analytical methods such as scanning electron microscopy coupled with energy dispersive x-ray spectroscopy and electron probe microanalysis with good agreement.

Qualitative and quantitative analysis of nanoparticles using laser-induced breakdown spectroscopy (LIBS) and energy dispersive x-ray spectroscopy (EDS)

“…LIBS is a type of atomic emission spectroscopy that uses highly energetic laser pulses as an excitation source. Because LIBS is a technique that is simple, easy to handle, less time consuming and fast for measurement, it is fascinating for the determination of the evo lution of mineral composition [4], archeological artifacts [7], cosmetics [8], thin films [9], polymers [10], detection and identification of bacteria [11] and micro and nanomaterials [12]. In the last decade, LIBS has also been used extensively in a variety of fields.…”

“…It is therefore becoming an important task to know the elemental composition of nanomaterials. In recent years, many techniques such as x-ray photoelectron spectroscopy [2], x-ray fluorescence [3] and energy-dispersive x-ray spectroscopy (EDS) [4] have been exploited for the compositional study. For the sake of accuracy and simplicity, the laser-induced breakdown…”