Feasibility Of Laser-induced Breakdown Spectroscopy Research Articles

Feasibility of laser-induced breakdown spectroscopy to elucidate elemental changes in human tooth ankylosis

Tooth ankylosis is a pathological condition associated with the loss of physiological tooth mobility when the firm fusion between the alveolar bone and the tooth root occurs. Causes of dental ankylosis are uncertain, so the analysis of elemental distribution in ankylotic and surrounding tissues could provide additional information about its initiation and progression. Here, we used Laser-Induced Breakdown Spectroscopy (LIBS) to determine differences in the mineral composition among ankylotic tissue, bone, and dental tissue taking advantage of its high throughput and multi-elemental capability. Elemental imaging was performed with a spatial resolution of 30 μm to evaluate the distribution of carbon, calcium, magnesium, phosphorus, and strontium in human tooth. To further verify the difference in the mineral composition of ankylotic tissue, the semi-quantitative content of these elements was compared within the region of interest. We revealed a significant increase in calcium, magnesium, and phosphorus contents in the ankylotic tissues. However, the contents of magnesium and phosphorus were not significantly changed. This finding suggests a mineral disbalance only of just certain elements in the tooth-bone interface area during the spread of ankylosis associated with an intense calcification of connective tissue. This paper brings a feasibility study and shows the way of LIBS data interpretation. We propose that the LIBS analysis on a micro-scale can contribute to the understanding of ankylotic tissue composition and can distinguish even small differences of carbon, calcium, magnesium, phosphorus, and strontium contents on the tooth-bone boundary during the initiation of ankylosis. Therefore, it represents a new useful tool for their future, more extensive analyses.

Feasibility of laser-induced breakdown spectroscopy for determination of neodymium in magnet alloys

The quantification of rare earth elements in (Nd–Pr)–FeB alloys used in the production of super magnets is required to ensure the quality of the raw material and a final product with suitable properties.

Feasibility of laser-induced breakdown spectroscopy as a direct raw bile analysis tool for screening of gallbladder cancer

Laser-induced breakdown spectroscopy (LIBS) was explored for the first time for discrimination of gallbladder (GB) polyp and GB cancer (GBC) by direct measurement of raw bile juice without pretreatment.

TEA CO2 Laser – Polymethyl Methacrylate Interaction: LIBS Hydrogen Analysis

The interaction of a Transversely Excited Atmospheric (TEA) CO2 laser with a polymer polymethyl methacrylate (PMMA) sample in a vacuum ambiance was studied. The main goal was to demonstrate the feasibility of laser-induced breakdown spectroscopy (LIBS) to detect hydrogen. The generation of plasma over the PMMA surface, using a low laser intensity of ∼ 48 MW/cm2 and fluence of ∼ 16.5 J/cm2, required the application of a metal sub-target. Besides hydrogen, the recorded spectra were dominated by atomic lines of carbon and oxygen and band emission of the C2 and CN molecules. The electron number density and temperature (ionic, vibrational, and rotational) were evaluated to characterize the laser-induced plasma. In addition, PMMA micro-damages (diameter ∼ 45 µm) created by a multipulse laser ablation could find potential applications in sensor technologies.

Laser Induced Breakdown Spectroscopy (LIBS): Application to Geological Materials-=SUP=-*-=/SUP=-

Laser-induced breakdown spectroscopy (LIBS) is emerging as an analytical tool for investigating geological materials. The unique abilities of this technique proven its potential in the area of geology. Detection of light elements, portability for in-field analysis, spot detection, and no sample preparation are some features that make this technique appropriate for the study of geological materials. The application of the LIBS technique has been tremendously developed in recent years. In this report, results obtained from previous and most recent studies regarding the investigation of geological materials LIBS technique are reviewed. Firstly, we introduce investigations that report the advancement in LIBS instrumentation, its applications, especially in the area of gemology and the extraterrestrial/planetary exploration have been reviewed. Investigation of gemstones by LIBS technique is not widely reviewed in the past as compared to LIBS application in planetary exploration or other geological applications. It is anticipated that for the classification of gemstones samples, huge data set is appropriate and to analyze this data set, multivariate/chemometric methods will be useful. Recent advancement of LIBS instrumentation for the study of meteorites, depth penetration in Martian rocks and its regolith proved the feasibility of LIBS used as robotic vehicles in the Martian environment. Keywords: LIBS, Gemstone, geological samples, Extra-terrestrial

Viabilidade da Espectrometria de Emissão Óptica com Plasma Induzido por Laser (LIBS) para Discriminação Multivariada de Sais Alimentícios

In the present study, the feasibility of Laser-Induced Breakdown Spectroscopy (LIBS) was investigated to analyze the main constituent chemical elements of 29 edible salt samples from Germany, Australia, Bolivia, Brazil, Cyprus, United States of America, France, the Himalayas, Iran and Pakistan. Such salts comprise iodized refined, iodized marine, ground iodized marine, hyposodic iodized marine, unrefined gourmet, Himalayan gourmet, yolk salt and food additive. The LIBS technique identified and evaluated the elements Al, Ca, Sr, Fe, Mg, Mn, K and Na. The data set obtained by LIBS was used in the developed multivariate classification model, principal components analysis (PCA). In the PCA 4 principal components (PC) were defined, which explain 83.77% of the spectral information matrix that were used to discriminate the origin and identify profiles of edible salts in national and imported salts and hyposodium salts. LIBS then proves to be a tool for origin indication analysis or origin determination, being capable of identifying possible tampering. Therefore, LIBS classification analyzes are very promising and represent a simplification in the handling and preparation of samples for analysis.

Feasibility of Laser-Induced Breakdown Spectroscopy and Hyperspectral Imaging for Rapid Detection of Thiophanate-Methyl Residue on Mulberry Fruit.

An effective and rapid way to detect thiophanate-methyl residue on mulberry fruit is important for providing consumers with quality and safe of mulberry fruit. Chemical methods are complex, time-consuming, and costly, and can result in sample contamination. Rapid detection of thiophanate-methyl residue on mulberry fruit was studied using laser-induced breakdown spectroscopy (LIBS) and hyperspectral imaging (HSI) techniques. Principal component analysis (PCA) and partial least square regression (PLSR) were used to qualitatively and quantitatively analyze the data obtained by using LIBS and HSI on mulberry fruit samples with different thiophanate-methyl residues. The competitive adaptive reweighted sampling algorithm was used to select optimal variables. The results of model calibration were compared. The best result was given by the PLSR model that used the optimal preprocessed LIBS–HSI variables, with a correlation coefficient of 0.921 for the prediction set. The results of this research confirmed the feasibility of using LIBS and HSI for the rapid detection of thiophanate-methyl residue on mulberry fruit.

Compositional depth profiles of the type 316 stainless steel undergone the corrosion in liquid lithium using laser-induced breakdown spectroscopy

Liquid metal lithium cause severe corrosion on the surface of metal structure material that used in the blanket and first wall of fusion device. Fast and accurate compositional depth profile measurement for the boundary layer of the corroded specimen will reveal the clues for the understanding and evaluation of the liquid lithium corrosion process as well as the involved corrosion mechanism. In this work, the feasibility of laser-induced breakdown spectroscopy for the compositional depth profile analysis of type 316 stainless steel which was corroded by liquid lithium in certain conditions was demonstrated. High sensitivity of LIBS was revealed especially for the corrosion medium Li in addition to the matrix elements of Fe, Cr, Ni and Mn by the spectral analysis of the plasma emission. Compositional depth profile analysis for the concerned elements which related to corrosion was carried out on the surface of the corroded specimen. Based on the verified local thermodynamic equilibrium shot-by-shot along the depth profile, the matrix effect was evaluated as negligible by the extracted physical parameter of the plasmas generated by each laser pulse in the longitudinal depth profile. In addition, the emission line intensity ratios were introduced to further reduce the impact on the emission line intensity variations arise from the strong inhomogeneities on the corroded surface. Compositional depth profiles for the matrix elements of Fe, Cr, Ni, Mn and the corrosion medium Li were constructed with their measured relative emission line intensities. The distribution and correlations of the concerned elements in depth profile may indicate the clues to the complicated process of composition diffusion and mass transfer. The results obtained demonstrate the potentiality of LIBS as an effective technique to perform spectrochemical measurement in the research fields of liquid metal lithium corrosion.

Feasibility of laser-induced breakdown spectroscopy (LIBS) as an at-line validation tool for calcium determination in infant formula

In this study, a 150 mJ laser-induced breakdown spectroscopy (LIBS) system was assessed to determine calcium content in infant formula (IF) samples. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers advantages over conventional methods such as real-time analyses, little to no sample preparation and ease of use. The aim of this work was to evaluate the feasibility of LIBS as an at-line tool for IF manufacturing. To this end, IF mixtures with varying content of calcium were prepared over a range (approx. 1.5–7 mg/g of calcium) selected to be in conformity with the guidelines provided by the Codex Alimentarius Commission. Atomic Absorption Spectroscopy (AAS) was used as the reference method for mineral content determination in IF. Partial least squares regression (PLSR) was applied to the LIBS spectral data to develop a calibration model for calcium content quantification. A validation approach was then carried out to investigate the robustness of the model, which showed a good fit with values of R2cv of 0.90 for cross-validation and a R2p 0.85 for external validation. Low values for root mean square errors of cross-validation (RMSECV) and prediction (RMSEP) of 0.62 mg/g and 0.68 mg/g were obtained. Furthermore, this study also illustrated the possibility of LIBS to provide mineral prediction maps as a useful tool for testing sample homogeneity.

Multivariate methods for analysis of environmental reference materials using laser-induced breakdown spectroscopy

Analysis of emission from laser-induced plasma has a unique capability for quantifying the major and minor elements present in any type of samples under optimal analysis conditions. Chemometric techniques are very effective and reliable tools for quantification of multiple components in complex matrices. The feasibility of laser-induced breakdown spectroscopy (LIBS) in combination with multivariate analysis was investigated for the analysis of environmental reference materials (RMs). In the present work, different (Certified/Standard) Reference Materials of soil and plant origin were analyzed using LIBS and the presence of Al, Ca, Mg, Fe, K, Mn and Si were identified in the LIBS spectra of these materials. Multivariate statistical methods (Partial Least Square Regression and Partial Least Square Discriminant Analysis) were employed for quantitative analysis of the constituent elements using the LIBS spectral data. Calibration models were used to predict the concentrations of the different elements of test samples and subsequently, the concentrations were compared with certified concentrations to check the authenticity of models. The non-destructive analytical method namely Instrumental Neutron Activation Analysis (INAA) using high flux reactor neutrons and high resolution gamma-ray spectrometry was also used for intercomparison of results of two RMs by LIBS.

Multi-elemental surface mapping and analysis of carbonaceous shale by laser-induced breakdown spectroscopy

Gas shale is one of the important unconventional hydrocarbon source rocks, whose composition, such as mineral components and redox sensitive trace elements, has been proved as important geochemical proxies playing essential roles in indicating the gas potential and gas productivity in recent geological researches. Fast and accurate measurements for the shale composition, especially those with spatial resolution, will reveal rich information for the understanding and evaluation of gas shale reservoirs. In this paper, we demonstrated the potentiality as well as feasibility of laser-induced breakdown spectroscopy as an effective technique to perform spectrochemical analysis for shale samples. In case of the bulk analysis of pressed shale pellet, spectral analysis of the plasma emission revealed high sensitivity of LIBS for major, minor and even trace elements. More than 356 lines emitted by 19 different elements can be found. Among these species, redox sensitive trace elements such as V, Cr, and Ni were detected with high signal-to-ratios. Two-dimensional surface micro-analysis for the concerned major or minor elements with strong emissions was then applied to the smoothed shale slab. Local thermodynamic equilibrium for the plasma was first verified with a line profile point-by-point on the sample surface, the matrix effect was then assessed as negligible by the extracted electron density and temperature of the plasmas induced at each position on the same profile. Concentration mappings for the major elements of Si, Al, Fe, Ca, Mg, Na and K were finally constructed with their measured relative variations of line emission intensities. The distribution and correlations of these elements in concentration may reflect changes of shale mineral components with respected to the variations of the depositional environments and provide an important clue in identifying sedimentary processes when combined with other geological or geochemical evidences. These results well demonstrated the potential of LIBS technique for shale studies.

Analysis of slags using laser-induced breakdown spectroscopy

The feasibility of laser-induced breakdown spectroscopy (LIBS) for the analysis of gasification slags was investigated by comparing LIBS results to the results of an ICP-OES analyzer. A small amount of slag sample was placed on a piece of double sided adhesive tape attached to a glass microscope slide and analyzed for Al, Ca, Fe, Si, and V which are major elements found in slags. The partial least squares regression (PLS-R) and univariate simple linear regression (SLR) calibration methods indicated that apart from V (accuracy up to +20%) the accuracy of analysis varies within 0.35–6.5% for SLR and 0.06–10% for PLS-R. A paired-sample t-test within the 95% confidence level yielded p-values greater than 0.05, meaning no appreciable statistical difference was observed between the univariate SLR with internal standardization and the multivariate PLS-R for most of the analytes. From the results obtained in this work, LIBS response varies depending on the element and the technique used for quantitative analysis. Simultaneous use of the univariate calibration curves with internal standard (intensity ratio) and PLS regression in multi-elemental analysis can help reduce the matrix effect of slags associated to their high variation in concentration. Overall, these results demonstrate the capability of LIBS as an alternative technique for analyzing gasification slags. Estimated limits of detection for Al, Ca, Fe, Si and V were 0.167, 0.78, 0.171, 0.243 and 0.01wt.%, respectively.

Feasibility of Laser-Induced Breakdown Spectroscopy for the Study of the Temporal Distribution of Trace Elements Trapped in Snow Collected from Greater Himalayan Range

ABSTRACT The potential merit of laser-induced breakdown spectroscopy (LIBS) has been demonstrated for detection and quantification of trace pollutants trapped in snow/ice samples. In this technique, a high-power pulsed laser beam from Nd:YAG Laser (Model no. Surelite III-10, Continuum, Santa Clara, CA, USA) is focused on the surface of the target to generate plasma. The characteristic emissions from laser-generated plasma are collected and recorded by a fiber-coupled LIBS 2000+ (Ocean Optics, Santa Clara, CA, USA) spectrometer. The fingerprint of the constituents present in the sample is obtained by analyzing the spectral lines by using OOI LIBS software. Reliable detection of several elements like Zn, Al, Mg, Fe, Ca, C, N, H, and O in snow/ice samples collected from different locations (elevation) of Manali and several snow samples collected from the Greater Himalayan region (from a cold lab in Manali, India) in different months has been demonstrated. The calibration curve approach has been adopted for the quantitative analysis of these elements like Zn, Al, Fe, and Mg. Our results clearly demonstrate that the level of contamination is higher in those samples that were collected in the month of January in comparison to those collected in February and March.

Determination of Cr in water solution by laser-induced breakdown spectroscopy with different univariate calibration models

In order to prove the feasibility of laser-induced breakdown spectroscopy (LIBS) in measuring toxic metals Cr in water solution, a series of potassium bichromate standard solutions were prepared in the lab. The characteristic line intensity of Cromium (Cr) element at 357.87, 359.35, 360.53, 425.43, 427.48, and 428.97 nm was taken to build up the correlation with concentration. The indexes of relative standard deviation, intercept, slope, R2 (coefficient of determination), and root mean square error of calibration were selected to verify the precision and accuracy of models. The comprehensive results showed that the 425.43 nm line had better superiority than other lines. And the detection limit of 6 ug/ml and repeatability of 3 % are reported. To improve the model accuracy further, the intensity ratio of single 425.43 nm line to the whole spectrum was extracted. And a linear relationship between the intensity ratio and the element Cr concentration was constructed. The results demonstrated the intensity ratio calibration had better accuracy than single line calibration, especially after smoothing. To verify the accuracy of prediction, the 100 ug/ml concentration sample was used as prediction sample. The relative error values are 13.2, 11.7, and 10.8 % for single line calibration, intensity ratio calibration with raw data, and by use of smooth processing data, respectively. The results further indicated that the intensity ratio calibration improved the accuracy of measurement than single line calibration. It is worth mentioning that the application of LIBS aiming the direct analysis of heavy metals in water is a great challenge that still needs efforts for its development and validation.

Studies on the feasibility of laser-induced breakdown spectroscopy in explosion proof atmospheres

One of the latest major innovations of the Institute for Mining and Metallurgical Machinery (IMR) is the adaption of a laser-induced breakdown spectrometer (LIBS) into the harsh conditions of surface mines. Usually working in the clean environment of laboratories, a compact analyzer consisting of a laser system and a spectrometer was developed to work in harsh environments which are affected by dust, mist, vibration and shock. Now, IMR is working on adjusting this laser system to underground conditions which are aggravated by the possibilities of methane explosions such as in hard coal mines. This project focusses on the conception of the enclosure and it's sampling for LIBS analysis. It is funded by the German Research Foundation (DFG).

Feasibility of Laser-Induced Breakdown Spectroscopy (LIBS) for Classification of Sea Salts

We have investigated the feasibility of laser-induced breakdown spectroscopy (LIBS) as a fast, reliable classification tool for sea salts. For 11 kinds of sea salts, potassium (K), magnesium (Mg), calcium (Ca), and aluminum (Al), concentrations were measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and the LIBS spectra were recorded in the narrow wavelength region between 760 and 800 nm where K (I), Mg (I), Ca (II), Al (I), and cyanide (CN) band emissions are observed. The ICP-AES measurements revealed that the K, Mg, Ca, and Al concentrations varied significantly with the provenance of each salt. The relative intensities of the K (I), Mg (I), Ca (II), and Al (I) peaks observed in the LIBS spectra are consistent with the results using ICP-AES. The principal component analysis of the LIBS spectra provided the score plot with quite a high degree of clustering. This indicates that classification of sea salts by chemometric analysis of LIBS spectra is very promising. Classification models were developed by partial least squares discriminant analysis (PLS-DA) and evaluated. In addition, the Al (I) peaks enabled us to discriminate between different production methods of the salts.

Investigation of laser-induced breakdown spectroscopy of a liquid jet

We investigate the feasibility of laser-induced breakdown spectroscopy for determination of heavy metal Pb in a Pb(NO3)2 aqueous solution by using a simple homemade vertical jet device and nanosecond laser pulses. Key experimental parameters that affect the analytical performance, such as delay of the time of observation, laser pulse energy, and liquid flow rate are optimized for the best limit of detection (LOD). The LOD was determined using Pb I emission at 405.781 nm, and after optimization, the 3σ LOD was found to be at the level of 60 ppm.