Laser-induced Breakdown Spectroscopy Emission Research Articles

Laser-induced breakdown spectroscopy (LIBS) of animal fat (lard): Efficient sample preparation for onsite analysis and influence of sample temperature on the signal intensity and plasma parameters

We report an efficient sample preparation method (freezing) for onsite fat and meat analysis via a specially designed thermoelectric cooling and temperature-controlling system. This investigation also focused on the effect of phase change on the sensitivity and reproducibility of LIBS emission signals and plasma parameters. The plasma emissions of animal fats (lard) were recorded when the sample was frozen (−2 °C), fluid (15 °C), and in a liquid state (37 °C) with a thermoelectric cooling system. At each temperature, the plasma emissions were acquired at laser pulse energy from 50 to 300 mJ and detector gate delay (DGD) from 0.5 to 5 μs. With increasing sample temperature, the DGD, where the optical emission intensity reached a maximum, decreased. At a laser pulse energy of 200 mJ and a sample temperature of −2 °C, the emission signals increased fourfold, the signal-to-noise ratio (SNR) improved tenfold, and the self-absorption in the emission lines decreased significantly. The repeatability of the emission signals and plasma parameters of frozen and liquid fat samples was determined using the relative standard deviation (RSD) of Se I (473.08 nm) and K I (766.48 nm) emission lines. The RSDs of the emission signals improved from 40 to 18 % and 37 to 16 %, whereas the shot-to-shot RSDs of the electron temperature and electron number density get improved from 11 to 6 % and 12 to 6.8 %, respectively.

Isotopic analysis of uranium at the picogram level with single-shot laser induced breakdown spectroscopy

Uranium was measured by laser induced breakdown spectroscopy (LIBS) with a limit of detection of 1.3 picograms with spectral-peak height as the analytical parameter, which shows an improvement of several orders of magnitude compared to other reports in the literature. The improvement is a result of optimizing the choice of the U analytical line, the system hardware, and the light collection and detection efficiency. The research established properties of U line emission (intensity, signal-to-background ratio, isotopic splitting, and spectral interferences) to select an optimum wavelength for analysis. The samples were mock particles from dried, monodispersed U solution droplets (∼65 pL in volume) deposited on Si wafers. LIBS emission spectra from several 235U-enriched samples were measured to demonstrate the performance for isotopic analysis. For isotopic measurements, two masses for total U, 100 pg and 325 pg, were studied. The 235U: 238U isotopic ratio was obtained by peak fitting the LIBS spectra without requiring calibration with the use of enriched standards. Depending on the total U mass and the 235U enrichment, typical relative standard deviations of the isotopic analysis ranged from several percent down to about 1%. Further, the developed method and the reported analytical performance were all based on single-shot LIBS. Overall, the study highlights the potential of LIBS as a robust and sensitive technique for isotopic analysis of U-containing particles.

Tracking organic matrix in the seashell by elemental mapping under laser-induced breakdown spectroscopy

As a biogenic calcium carbonate, the seashell plays a crucial role in marine environmental studies. In these studies, it is essential to investigate the composition of the seashell. In this study, we used laser-induced breakdown spectroscopy (LIBS) to analyze the elemental composition of cultured scallop-shell (Patinopecten yessoensis), with a specific focus on examining the organic elements (C, N, O, H) to track the shell organic matrix (SOM). Our findings indicate that the seashell organic layer can be accurately identified by referencing the strong emission of nitrogen or the low signal of calcium. To further confirm the presence of this layer, we employed fluorescence spectroscopy, Raman spectroscopy and FTIR spectroscopy. Correlation analysis revealed a strong connection between LIBS emissions (H, O, CC) and seashell organics, as well as demonstrated the presence of organics in metallic emissions (Si, Ba). However, when we conducted elemental mapping on the shell cross-section, the distribution similarity was observed between the elements N, Ba, and Sr. Based on the correlation of organics and the distribution similarity, it is concluded that barium is an element associated with the SOM. These results highlight the potential of LIBS for organic analysis, which can complement traditional seashell analysis.

Effect of laser polarization on atomic and ionic emissions in Laser-Induced Breakdown Spectroscopy (LIBS)

Laser-Induced Breakdown Spectroscopy (LIBS) is attracting a great deal of interest in qualitative and quantitative analysis of materials. Close observation reveals that developments in the science that underpins LIBS as an analytical technique are limited to either signal enhancement strategies or newer data analysis techniques that facilitate better interpretation of raw LIBS data. Developments related to the excitation part of LIBS have been restricted to the effects of laser beam characteristics or the effect of ambient experimental conditions. The influence, if any, of the polarization state of the excitation laser has largely remained unexplored. We address this lacuna by probing the influence of different polarization states of the excitation laser on LIBS spectra of metals (copper and silver) and non-metals (polyethylene) by analyzing the polarization-dependent behavior of both atomic and ionic emission lines. Our observations open the possibility of tackling the problem of relatively faint emissions from ionic species in the plasma by appropriately manipulating the polarization state of the incident laser beam; this may lead to easy-to-implement improvement in the performance of LIBS instruments.Graphical abstract

Investigating the Soil Unconfined Compressive Strength Based on Laser-Induced Breakdown Spectroscopy Emission Intensities and Machine Learning Techniques.

Laser-induced breakdown spectroscopy (LIBS) is a remarkable elemental identification and quantification technique used in multiple sectors, including science, engineering, and medicine. Machine learning techniques have recently sparked widespread interest in the development of calibration-free LIBS due to their ability to generate a defined pattern for complex systems. In geotechnical engineering, understanding soil mechanics in relation to the applications is of paramount importance. The knowledge of soil unconfined compressive strength (UCS) enables engineers to identify the behaviors of a particular soil and propose effective solutions to given geotechnical problems. However, the experimental techniques involved in the measurements of soil UCS are incredibly expensive and time-consuming. In this work, we develop a pioneering technique to estimate the soil unconfined compressive strength using artificial intelligent methods based on the spectra obtained from the LIBS system. Decision tree regression (DTR) and support vector regression learners were initially employed, and consequently, the adaptive boosting method was applied to improve the performance of the two single learners. The prediction power of the established models was determined using the standard performance evaluation metrics such as the root-mean-square error, CC between the predicted and actual soil UCS values, mean absolute error, and R2 score. Our results revealed that the boosted DTR exhibited the highest coefficient of correlation of 99.52% and an R2 value of 99.03% during the testing phase. To validate the models, the UCS values of soils stabilized with lime and cement were predicted with an optimum degree of accuracy, confirming the models' suitability and generalization strength for soil UCS investigations.

Emission Enhancement in fs + ns Dual-Pulse LIBS of Cu

Femtosecond (fs) and nanosecond (ns) laser pulses have their own advantages and disadvantages in laser-induced breakdown spectroscopy (LIBS). This paper investigated fs + ns (FN) dual-pulse (DP) LIBS, utilizing the respective advantages of two laser pulses in LIBS. Compared to traditional single ns LIBS, applying a smaller energy fs pulse could effectively improve the LIBS emission. Firstly, this study discussed the spectra of FN DP LIBS with overlapping pulse time—that is, the FN DP inter-pulse delay (DID) was 0 μs. The results showed that the spectra were increased to three times that of a single ns LIBS. Subsequently, the DID between the two pulses was optimized. The results showed that as the DID between the two pulses increased, the spectral emission first increased and then decreased, ultimately remaining unchanged. The optimized DID was approximately 2 μs. Finally, using this optimized DID, the variation of spectral intensity with ns laser energy was discussed in DP LIBS. The spectral enhancement ratio increased from 3 with 0 μs DID to 6 with 2 μs DID. The investigation provides a reference in the application of FN DP LIBS element analysis.

Optical and thermal characterization of pure CuO and Zn/CuO using laser-induced breakdown spectroscopy (LIBS), x-ray fluorescence (XRF), and ultraviolet–visible (UV–Vis) spectroscopy techniques

We present elemental analysis and thermal characterization of pure and two different concentrations of zinc-doped copper oxide (CuO) samples using different analytical techniques. The quantitative as well as qualitative investigations, were performed by incorporating calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique. The plasma was generated on the samples surface by focusing a first harmonic of Nd: YAG laser of 1064 nm wavelength and the time-integrated emission spectra was achieved through a set of five spectrometers equipped with a charge-coupled-device. The acquired optical emission spectra from laser-generated plasma show different concentrations of zinc and copper in different samples which are consistent with their percentage composition measured during the sample synthesis. Using LIBS emission analytical lines, the Boltzmann technique was utilized for estimating the excitation temperature, while the number density was evaluated using the well-known Stark broadening line profile method. Besides, the CF-LIBS elemental analysis was validated by the x-ray fluorescence technique. For the optical study, ultraviolet–visible spectroscopical analysis was performed to find the bandgap of pure and zinc-doped copper oxide samples and consequently, variation in bandgap was studied with the growth of zinc doping. In addition, the thermal properties of the samples were analyzed using the beam deflection spectroscopy technique. The results shows that thermal diffusivity () and thermal conductivity (), increased with an increase in zinc concentration.

Direct comparison of ns LIBS and fs LIBS with high spatial and temporal resolution in gases

Spatial resolution is one of the most critical parameters for spectroscopic measurements especially when used in gases. However, the lateral resolution of femtosecond (fs) laser-induced breakdown spectroscopy (LIBS) in gases has not been thoroughly investigated. Here, we directly compare the differences and connections between nanosecond (ns) LIBS and fs LIBS through spatio-temporally resolved spectroscopy. At the time period we measured, unlike the ns LIBS plasma, the fs LIBS plasma does not show detectable expansion, and we do not find composition transport due to turbulence inside the fs LIBS. In other words, the local spectral emission in the fs LIBS can correlate precisely to the composition at that location before the arrival of the laser, while ns LIBS cannot. This feature allows fs LIBS to have much higher lateral resolution than ns LIBS. Finally, this paper verified that fs LIBS can be used for one-dimensional measurements capability with its lateral resolution of 50 μm.

Influence of inter-pulse delay on CN molecular emission from femtosecond-nanosecond double-pulse laser-induced breakdown spectroscopy of PMMA

An experimental study on molecular emission in laser-induced breakdown spectroscopy (LIBS) was performed using an integrated femtosecond (fs) and nanosecond (ns) double-pulse (DP) laser scheme at the different inter-pulse delay between the fs and ns pulses. This work mainly included the influence of the DP inter-pulse delay on the spectral emission intensity and signal-to-background ratio (SBR). The ablated sample was polymethyl methacrylate (PMMA), and the measured molecular band was CN (Δv = 0) in the B2Σ+ − X2Σ+ transition. The results showed that the negative (ns + fs scheme) and positive (fs + ns scheme) inter-pulse delays were not much different in terms of spectral emission. The SBR excited by the fs + ns DP was higher than that excited by the ns + fs DP, and the maximum value of the SBR in the fs + ns DP-LIBS scheme was about two times that in the ns + fs DP-LIBS scheme. The higher SBR was suitable for spectral analysis, and was easy to reduce the influence of continuous emission on spectral analysis. Also, the vibration temperature of the CN molecule as a function of the inter-pulse delay between the two laser pulses was discussed. This discovery fully demonstrates that the fs + ns DP-LIBS is of great significance for detecting molecular emissions in LIBS.

Probabilistic multivariable calibration for major elements analysis of MarSCoDe Martian laser-induced breakdown spectroscopy instrument on Zhurong rover

Mars Surface Composition Detector (MarSCoDe) is one of the major payloads onboard the Zhurong rover. The laser-induced breakdown spectroscopy (LIBS) component within MarSCoDe is capable of acquiring LIBS emission from 240 to 850 nm at targets ranging from 1.6 to 7 m. To address the previous issue of the indirect uncertainty estimation on the calibrations of other Martian LIBS, a recently developed natural gradient boosting probabilistic prediction (NGBoost) ensemble learning method was adopted for the LIBS calibration of MarSCoDe. Probabilistic Major Element Composition (PMEC) models based on NGBoost were established with the capacity of predicting the concentrations of 8 major element oxides (SiO2, TiO2, Al2O3, Fe2O3T, MgO, CaO, Na2O, K2O) in the form of normal distributions. The models were trained based on a ground spectral repository from MarSCoDe LIBS records of various reference samples. Optimizations for robustness and performance of the models were carried out with tunable max-pooling feature extraction and cross-validation-controlled hyperparameter tuning. The models were tested on an independent portion of the ground spectral repository and were checked with LIBS spectra of onboard calibration targets from Mars for their accuracy, error significancy relative to predicted uncertainty, consistency among single and averaged shots, and tolerance to mocked wavelength shifts. The PMEC models are presumably competent for basic elemental analysis of Martian silicate soil and rock along Zhurong's expedition. The limitation and interpretability of the models were also discussed to guide further works.

Geochemistry study of soil affected catastrophically by tsunami disaster triggered by 2004 Indian Ocean earthquake using a fourth harmonics (λ = 266 nm) Nd:YAG laser induced breakdown spectroscopy

In this work, laser induced breakdown spectroscopy (LIBS) analysis of the soil samples collected from Aceh, a place in Indonesia worst affected by 2004 Indian Ocean tsunami, was conducted. In the LIBS experimental system, a high energy pulsed laser beam was focused on the tsunami affected soil samples and the atomic emission lines, originating from the laser induced plasma were recorded using locally developed laser induced breakdown spectrometer. Our results show that the concentrations of many elements especially terrestrial markers, namely titanium, iron, and carbonate marker such as magnesium, are higher in the tsunami-affected samples than that in the unaffected samples collected from the same neighborhood. The quantification of Ti, Fe and Mg were carried out using Ti II 334.94, Fe I 438.35, and Mg I 277.98 nm atomic transition lines respectively by drawing the calibration curve by preparing the samples of known concentrations in unaffected soil matrix. In order to ensure accurate quantification, the local thermal equilibrium of the laser-induced plasma was verified using Mc Writher criterion, for which the plasma temperature was estimated using linearized Boltzmann plot for six iron atomic transition lines and the electron number density in the plasma was estimated using Stark broadened Fe I 540.4 nm atomic lines. The estimated temperature and electron number density of the laser induced plasma are 9642 K and 3.5 × 10 16 cm −3 respectively. The concentrations of Ti, Fe and Mg in tsunami unaffected soil are 0.09, 3.2 and 0.02 w/w% and in tsunami affected soil are 0.14, 7.9 and 0.048 w/w% respectively. These values are in good agreement with XRF data. The elemental ratios extracted from LIBS signal intensity revealed that LIBS emission intensity ratios of several elements, such as Si/Ti, Al/Ti and Sr/Ba are potential candidates as the distinctive geochemical signature for identification the soil impacted and unimpacted by the 2004 Indian Ocean giant tsunami. The advantage of using LIBS for the elemental analysis is that the sample can be analyzed in its pristine form without any need cumbersome sample preparation method, which has the risk of bringing in external additives through chemicals used for the sample preparation. Other advantages of LIBS technique are that the analysis can be in situ and can be carried out remotely.

Silver Microparticle-Enhanced Laser-Induced Breakdown Spectroscopy.

Enhanced emission was observed in the laser-induced breakdown spectroscopy (LIBS) atomic emission spectra of bacterial cells deposited upon a nitrocellulose filtration medium in the presence of one-micron silver microparticles. A deposition chamber was constructed that allowed a uniform coating of the filter with trace amounts of silver microparticles. Masses from 10 to 100 μg were deposited in a circular area of 52.18 mm2. A 30 s deposition time was used for all experiments resulting in a mass deposition of 39 μg ± 17 μg. This mass coverage on the filter provided for a single laser shot silver mass ablation of 3.3 ng per laser shot. LIBS spectra were acquired with single-shot 1064 nm laser pulses from specimens of E. coli, M. smegmatis, and E. cloacae deposited on both microparticle-coated filters and blank filters. An increase in emission intensity for all elements detected in the bacterial LIBS spectrum as well as the carbon emission which derives in part from the nitrocellulose filter medium was observed due to the ablation with silver microparticles relative to the intensity measured from the ablation of bacterial cells deposited on a blank filter. The ratio of emission intensity with microparticles to emission intensity without microparticles was measured to be 3.6 for phosphorus, 4.5 for magnesium, 5.3 for calcium, 4.0 for sodium, and 1.2 for carbon. An enhancement in LIBS emission intensity in the range of 1–10 was observed for all the spectra, with an average enhancement ratio of 4.3.

Access to quantitative analysis of carbonates using a portable LIBS instrument: First applications to single minerals and mineral mixtures

Natural carbonate standards of calcite structure were analysed using a handheld Laser-Induced Breakdown Spectroscopy (LIBS) device to investigate the spectral applicability for quantitative analysis in the Ca-Mg-Fe-Mn carbonate system. To obtain an initial understanding of the relationship between the elemental concentrations and LIBS signals, the determination coefficient (R2), root mean square error (RMSE) and mean arctangent absolute percentage error (MAAPE) for cross-validation and forecast accuracy were used, respectively. To relate the changes in spectral characteristics to the mineral content of carbonate mixtures, different spectral ratios were compared with mixture ratios between the two carbonate minerals. We found that spectral information from LIBS emission lines showed high correlations to their elemental concentration (Ca, Mg, Fe, and Mn), and their spectral ratios in carbonate mixtures showed a linear correlation with mineral content. Principal component analysis (PCA) was investigated the chemometric capability of the discrimination for carbonate minerals. This study demonstrates that handheld LIBS can be effectively applied in the field for the discrimination and identification of carbonate endmembers and their quantification for the case of mixtures.

Application of Molecular Emissions in Laser-Induced Breakdown Spectroscopy: A Review

Laser-induced breakdown spectroscopy (LIBS) with advantages of rapid, in situ, and little sample pretreatment has been used in various fields. However, LIBS technology remains challenging in the detection of halogens, isotopes, and samples with similar elements. Therefore, molecular emission was proposed to improve the detection ability of LIBS. In this review, we introduced molecular emissions formed by organic elements, oxidizable elements, and halogens. Then, molecular emission in different experiment parameters, such as the acquisition window, laser characters (laser energy, laser wavelength, and pulse duration), and ambient atmospheres, were discussed. In the end, we highlight the application of molecular emissions on element content determination, material type classification, and combustion and explosion process monitoring.

Refractory residues classification strategy using emission spectroscopy of laser-induced plasmas in tandem with a decision tree-based algorithm

The recycling of refractory scraps began to be forged just over a decade ago. Until then, virtually all refractory scraps were disposed off in landfill sites without any application. Over these past few years, a growing interest and a gain steady momentum of the circular economy, the emergent framing around waste and resource management that promotes the notions of their productive cycling, has been the driving force towards the “zero waste” culture across the spectrum of refractory users and producers. In this way, the circular economy, operated following strategies such as, but not limited to, reusing, recycling, and remanufacturing, has played the pillar role in the different essential value chains of the refractory industry to the entering the new era of secondary raw material supply. In any case, prior to starting any sustainable process, it is really necessary to know the wastes and to classify them. In this context, the present research focused on a refractory residue-classification strategy based on combined laser-induced breakdown spectroscopy (LIBS) and a decision tree algorithm for a qualitative analytical performance. This tandem approach allowed the categorization of a rich set of residues in up to 10 different refractory groups. By choosing original LIBS emission intensities and intensity ratios involving the most relevant constituent elements (Al, Mg, C ‒through its related-species CN‒, Si and Zr) of various refractory wastes, a decision tree with multiple nodes that decided how to classify inputs was designed and trained. Categorization performed from LIBS emission spectra of "blind" refractory residues showed that LIBS data combined with this supervised machine learning algorithm provided good refractory scraps-classification performance, with a classification accuracy of up to 75%. However, some more than justified decisions of the algorithm on allegedly misclassified residues showed that scores for the decision tree could found to be far superior to those obtained. The results achieved support the strategy designed for its industrial implementation, either directly in the iron and steel industry, as the major end-user of refractories, in the refractory waste management industry, or in both.

In situ diagnostic investigation on the structure distribution of inverse diffusion flames based on laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was applied to the measurement of methane-oxygen inverse diffusion flames. The correlation between the LIBS emission spectra intensity of different atoms and the overall flame equivalence ratio was investigated by varying the oxygen-fuel equivalence ratio ([O/C]e). Moreover, the applicability of LIBS for local chemical composition measurement in flames was analyzed. The results indicate that the dependence of O(777.2 nm)/H(656.3 nm) spectral intensity ratio on laser energy is negligible. The spectral intensities of C, H and O atoms first increase and then decrease with the increase of axial height, and the radial variations are symmetrically distributed. In addition, the variation of C(247.8 nm)/H(656.3 nm) and O(777.2 nm)/H(656.3 nm) atomic spectral intensity reflects the characteristics of soot formation in flame. The local equivalence ratios at different radial positions at different heights of lean and rich flames were characterized by establishing the linear relationship between the oxygen-hydrogen intensity ratio and the flame equivalence ratio, and the information on the flame structure and dynamics was provided. Thus, it is of great significance for the analysis of flame to reasonably clarify the stability of the determination of atomic composition by LIBS.

Chemical Characterization Using Laser-Induced Breakdown Spectroscopy of Products Released from Lithium-Ion Battery Cells at Thermal Runaway Conditions.

Laser-induced breakdown spectroscopy (LIBS) was used to characterize the ejecta released by lithium-ion (Li-ion) cells at thermal runaway conditions. Commercial AAA-size, rechargeable, 3.7 V, 350 mAh, Li-ion battery cells were heated in a N2 -atmosphere tubular chamber up to about 165 ℃ to induce thermal decomposition. Through measurements of the chamber internal temperature and LIBS emission intensities over, time the onset temperature of thermal runaway (≈143 ℃) and the duration of the cells outgassing (>40 minutes) were determined. Relatively high-intensity atomic emissions from C, F, H, Li, Na, and P were detected at different times during the heating experiments. The detection of analytes such as C and H was continuous over time. On the contrary, detection of F, Li, Na, and P was more irregular, indicating the presence of solid-phase analytes or analyte-bearing particles. A calibration scheme for estimation of the total mass/volume concentration of all carbon-based species sampled within the laser-induced plasma was developed.

Diagnosis of Gulf War Illness Using Laser-Induced Spectra Acquired from Blood Samples

Gulf War illness (GWI) is a chronic illness with no known validated biomarkers that affects the lives of hundreds of thousands of people. As a result, there is an urgent need for the development of an untargeted and unbiased method to distinguish GWI patients from non-GWI patients. We report on the application of laser-induced breakdown spectroscopy (LIBS) to distinguish blood plasma samples from a group of subjects with GWI and from subjects with chronic low back pain as controls. We initially obtained LIBS data from blood plasma samples of four GWI patients and four non-GWI patients. We used an analytical method based on taking the difference between a mean LIBS spectrum obtained with those of GWI patients from the mean LIBS spectrum of those of the control group, to generate a "difference" spectrum for our classification model. This model was cross-validated using different numbers of differential LIBS emission peaks. A subset of 17 of the 82 atomic and ionic transitions that provided 70% of correct diagnosis was selected test in a blinded fashion using 10 additional samples and was found to yield 90% classification accuracy, 100% sensitivity, and 83.3% specificity. Of the 17 atomic and ionic transitions, eight could be assigned unambiguously to species of Na, K, and Fe.

Effect of crater volume on laser-induced plasma lasers and Laser-Induced Breakdown Spectroscopy intensity

Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Induced Plasma Lasers (LIPL) in elongated Laser-Induced Plasma (LIP) are investigated. It is shown that LIBS and LIPL behavior versus ablation laser pulses are about the same, though LIBS emission is proportional to the atoms in excited states, but LIPL generation is proportional to the atoms in the ground state. Furthermore, two peaks are found in LIBS/LIPL intensities dependencies on laser pulses. The first peak is well-known in LIBS. The second, observed at large ablation pulses number (≥104 pulses in our experimental conditions), may be attributed to the sample's thermal properties, especially thermal capacity and thermal diffusivity.

LIBS technique combined with blow gas and vacuum suction to remove particle cloud and enhance emission intensity during characterization of powder samples

The present study reports developing a bench-top Laser-Induced Breakdown Spectroscopy (LIBS) set up for the online analysis of powder samples without sample preparation. The powder particle blow-off during pulsed laser ablation was mitigated by adding a blow gas (an inert gas blown across the ablation surface) and a suction unit (for extraction of the blow gas and blown-off particle cloud) to the existing LIBS setup. The influence of a blow-gas combined with a suction unit on LIBS emission intensity from coal powder and flyash particles is studied in the present work. The effect of the blow gas flow rate and the suction pressure was studied on the LI-BS emission intensity and removal of the laser blown-off particle cloud. The combination gas flow at 2 lpm (liter per minute) flow rate and suction at 925 mbar (absolute) show an increase in the LIBS emission intensity and effective particle removal. The ratio of LIBS emission intensity of the powder sample and solid-target (pellet) sample improved from 0.25 without the Ar gas flow and the suction unit to 0.85, which is by a factor of 3.4 times with the proposed approach.