The high dependence of polarization resolved laser-induced breakdown spectroscopy on experimental conditions

This paper reports on the simultaneous detection of Mg, Mn, Fe and Pb in Al samples using laser-induced breakdown spectroscopy and optical multichannel analysis of the photoablated microplasma. Using calibrated samples, well characterized linear working curves were determined for these minor components over the 0.01–1% concentration range. In addition optimum experimental conditions were found that allow the analysis to be carded out in a fast and non-invasive manner. The potential application of the method to on-line industrial analysis is also suggested.

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Sample Presentation Considerations in Laser-Induced Breakdown Spectroscopy in Aqueous Solution

Applied Spectroscopy ◽

10.1366/000370207781745964 ◽

2007 ◽

Vol 61 (9) ◽

pp. 1021-1024 ◽

Cited By ~ 16

Author(s):

Xiao Fang ◽

S. Rafi Ahmad

Keyword(s):

Elemental Analysis ◽

Aqueous Media ◽

Water Jet ◽

Laser Induced Breakdown Spectroscopy ◽

Signal To Noise ◽

Experimental Conditions ◽

Breakdown Spectroscopy ◽

Laser Induced Breakdown ◽

Sample Presentation ◽

Presentation Methods

Various sample presentation configurations for elemental analysis in aqueous media by laser-induced breakdown spectroscopy (LIBS) have been tested and analyzed. Direct and quantitative comparison between the two different sample presentation methods, plasma excitation within water bulk and on the surface in a water jet, has been carried out using the same LIBS system under the same experimental conditions. Temporal characteristics of light emitted from the plasma induced in both the water bulk and the jet surface containing calcium (Ca) were recorded and presented. Spectral data recorded under optimum detection gating conditions showed that the signal-to-noise ratio (S/N) for excitation in the water jet configuration is approximately 10 times higher than that in the bulk excitation, the actual values of enhancement being dependent on the element type. The typical spectra of aqueous samples containing sodium (Na), calcium (Ca), zinc (Zn), cadmium (Cd), and mercury (Hg) were detected and the signal-to-noise ratios were evaluated and compared for the sample presentation configurations under considerations. The results suggest that for better sensitivity of detection, a simple water jet sample presentation configuration could be designed and implemented for cost-effective commercial use of this technique for elemental analysis in a water environment.

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Temporal Gating for the Optimization of Laser-Induced Breakdown Spectroscopy Detection and Analysis of Toxic Metals

Applied Spectroscopy ◽

10.1366/0003702011953667 ◽

2001 ◽

Vol 55 (10) ◽

pp. 1312-1319 ◽

Cited By ~ 76

Author(s):

Brian T. Fisher ◽

Howard A. Johnsen ◽

Steven G. Buckley ◽

David W. Hahn

Keyword(s):

Toxic Metals ◽

Delay Time ◽

Atomic Emission ◽

Metal Species ◽

Laser Induced Breakdown Spectroscopy ◽

Experimental Conditions ◽

Breakdown Spectroscopy ◽

Select Group ◽

Delay Times ◽

Laser Induced Breakdown

Optimal temporal gating for laser-induced breakdown spectroscopy (LIBS) analysis was investigated for a select group of toxic metals, namely the Resource Conservation and Recovery Act (RCRA) metals arsenic, beryllium, cadmium, chromium, lead, and mercury. The differing rates of decay between the continuum plasma emission and the atomic emission were used as a means to maximize the signal-to-noise ratio of the atomic emission lines for these six metal species. Detection windows were investigated corresponding to delay times from 2 to 50 μs following the plasma-initiating laser pulse. For the current experimental conditions, it is concluded that the relatively short delay time of 12 μs is optimal for the detection of arsenic, beryllium, cadmium, and mercury, while a longer delay time of 50 μs is optimal for the detection of chromium and lead. The reduced atomic emission intensity at relatively long delay times is compensated for by the use of long detector gate widths. Estimated detection limits are reported for the six metal species based on the optimized temporal gating and ensemble averaging of multiple laser pulses, and the implications for simultaneous metals monitoring are discussed.

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Measuring Heavy Metals Content in Wastewater Using Laser Induced Breakdown Spectroscopy

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.21.69 ◽

2013 ◽

Vol 21 ◽

pp. 69-75

Author(s):

S. Ali ◽

H. Jamil ◽

M. Imran

Keyword(s):

Laser Induced Breakdown Spectroscopy ◽

Experimental Conditions ◽

Flame Atomic Absorption Spectroscopy ◽

Analytical Technique ◽

Breakdown Spectroscopy ◽

Fundamental Wavelength ◽

Flame Atomic Absorption ◽

Maximum Pulse Energy ◽

Laser Induced Breakdown

In the present study, laser-induced breakdown spectroscopy (LIBS) has been applied for the determination of chromium and cadmium contents in wastewater of different canneries surrounding by leather factories. The plasma was generated with a Q-switched Nd:YAG laser having a fundamental wavelength of 1064 nm and delivers maximum pulse energy of 180 mJ. Experimental conditions were optimized to improve the sensitivity and to get a reasonable signal from the generated plasma. The results show that the concentration of chromium and cadmium are varying in different samples depending on the incoming flow of the wastewater from factories. The results from LIBS and standard analytical technique called flame atomic absorption spectroscopy (FAAS) were compared and found in good agreement within the experimental uncertainties.

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Influences on Concentration Measurements of Liquid Aerosols by Laser-Induced Breakdown Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702953964138 ◽

1995 ◽

Vol 49 (5) ◽

pp. 569-579 ◽

Cited By ~ 40

Author(s):

Dana E. Poulain ◽

Dennis R. Alexander

Keyword(s):

Excimer Laser ◽

Intensity Ratio ◽

Droplet Diameter ◽

Current Method ◽

Atomic Emission ◽

Laser Induced Breakdown Spectroscopy ◽

Experimental Conditions ◽

Probe Volume ◽

Breakdown Spectroscopy ◽

Laser Induced Breakdown

Results are presented for laser-induced breakdown spectroscopy (LIBS) as a method for measuring salt concentrations in seawater aerosol droplets. An excimer laser, operating at high pulse energy with KrF gas (λ = 248 nm) produces laser-induced breakdown plasmas in an aerosol spray. Emission lines of Na and H are monitored with an optical multichannel analyzer to characterize the plasma spatially and temporally. Studies of temporally resolved atomic line emissions from the plasma determine the optimum time for gating of the detector to be 2–4 μs after the excimer laser pulse arrives in the probe volume. Spatially resolved measurements of atomic emission line intensities are studied by positioning a stream of monodisperse droplets at various locations relative to the measurement probe volume. The electron temperature of the plasma is estimated to be 12,600 ± 4600 K, averaged over 1700 measurements during a 100-ns interval 2 μs after breakdown. Calibration curves are presented relating the Na(I) 589-nm to Hα 656.3-nm intensity ratio as a function of Na concentration, ranging from 100 to 10,000 ppm. Limits of detection for Na by the current method under the experimental conditions are estimated to be approximately 165 ppm for monodisperse sprays and 925 ppm for one case involving a polydisperse spray. Droplet diameter strongly influences the observed emission intensity ratio.

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Investigation of the Effects of Atmospheric Conditions on the Quantification of Metal Hydrides Using Laser-Induced Breakdown Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702963905619 ◽

1996 ◽

Vol 50 (6) ◽

pp. 764-773 ◽

Cited By ~ 44

Author(s):

Jagdish P. Singh ◽

Hansheng Zhang ◽

Fang-Yu Yueh ◽

Kevin P. Carney

Keyword(s):

Steady State ◽

Neutral Atom ◽

Metal Hydrides ◽

Laser Induced Breakdown Spectroscopy ◽

Gas Composition ◽

Atmospheric Conditions ◽

Experimental Conditions ◽

Laser Induced Plasma ◽

Breakdown Spectroscopy ◽

Laser Induced Breakdown

A study was performed to evaluate the performance characteristics of a laser-induced plasma for real-time determination of various gas-phase metal hydrides, specifically Sn and As. The choice of carrier gas composition and the effect of the pressure on the temporal emission behavior of neutral atoms excited by the laser-induced plasma were investigated. Metal hydrides were generated by using a NaBH4-based hydride generation system. The hydrides were equilibrated into an evacuated cell and isolated from the generator prior to measurement. Laser-induced breakdown spectroscopy (LIBS) spectra of Sn and As were recorded in He and N2 atmospheres at 300 and 760 Torr. The temporal behavior of the LIBS signal was most affected by gas composition, gas pressure, and intensity of the laser beam. The Sn neutral atom emission (284.0 nm) in a N2 atmosphere decreased exponentially with time. In contrast, with a He atmosphere and identical experimental conditions, the Sn signal increased logarithmically with time over the first 100 s. Then the signal maintained a steady-state value until approximately 400 s, after which it decreased exponentially. The steady-state time depends on the concentration of metal hydride. The variation of the LIBS signal with time was mirrored for the As neutral atom emission in He and N2 atmospheres. Various experiments have been performed to find the possible reason for the signal variation with time. It was found that chemical reactions in the laser plasma that might deplete the metal from the gas volume were responsible for the decrease in the signal with time.

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Laser-Induced Breakdown Spectroscopy Analysis of Lead Aerosol in Nitrogen and Air Atmosphere

Applied Spectroscopy ◽

10.1177/0003702817742314 ◽

2017 ◽

Vol 72 (4) ◽

pp. 584-590 ◽

Cited By ~ 3

Author(s):

Daniele A. Redoglio ◽

Natascia Palazzo ◽

Francesca Migliorini ◽

Roberto Dondè ◽

Silvana De Iuliis

Keyword(s):

Laser Pulse ◽

Delay Time ◽

Plasma Temperature ◽

Laser Induced Breakdown Spectroscopy ◽

Experimental Conditions ◽

Breakdown Spectroscopy ◽

Air Atmosphere ◽

Laser Induced Breakdown ◽

Carrier Gases ◽

Pb Concentration

In this work, laser-induced breakdown spectroscopy (LIBS) is applied for quantitative measurements of Pb in aerosols. In order to investigate the carrier gas role and, in particular, the effect of O2 addition to the gas itself, measurements are carried out in nitrogen and air atmosphere. Aerosol particles are produced by nebulizing Pb(CH3COO)2 * 3H2O aqueous solutions of known concentration and the atomic line of 405.8 nm is detected as Pb signature. The plasma generated with the laser pulse is characterized in terms of plasma temperature and electron density, showing no substantial differences with the two carrier gases used. The behavior of the LIBS signal as a function of the delay time with respect to the laser pulse is investigated changing the environmental conditions and, in particular, the Pb concentration values. The different trends registered in the case of relatively short (up to 20 μs) and long delay time, resulting to be the same whatever the Pb concentration value, could have a significant effect on the calibration curve performed in different experimental conditions.

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Matrix Effects in the Detection of Pb and Ba in Soils Using Laser-Induced Breakdown Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702963905123 ◽

1996 ◽

Vol 50 (9) ◽

pp. 1175-1181 ◽

Cited By ~ 195

Author(s):

Aaron S. Eppler ◽

David A. Cremers ◽

Donald D. Hickmott ◽

Monty J. Ferris ◽

Aaron C. Koskelo

Keyword(s):

Matrix Effects ◽

Detection Limits ◽

Measurement Precision ◽

Matrix Composition ◽

Laser Induced Breakdown Spectroscopy ◽

Spherical Lens ◽

Experimental Conditions ◽

Breakdown Spectroscopy ◽

Spiked Soil ◽

Laser Induced Breakdown

With the use of laser-induced breakdown spectroscopy (LIBS), the effects of chemical speciation and matrix composition on Pb and Ba measurements have been investigated by using sand and soil matrices. A cylindrical lens was used to focus the laser pulses on the samples because it yielded higher measurement precision than a spherical lens for the experimental conditions used here. The detection limits for Pb and Ba spiked in a sand matrix were 17 and 76 ppm (w/w), respectively. In spiked soil, the detection limits were 57 and 42 ppm (w/w) for Pb and Ba, respectively. Measurement precision for five replicate measurements was typically 10% RSD or less. Two factors were found to influence emissions from Pb and Ba present in sand and soil matrices as crystalline compounds: (1) compound speciation, where Ba emission intensities varied in the order carbonate > oxide > sulfate > chloride > nitrate, and where Pb emission intensities varied in the order oxide > carbonate > chloride > sulfate > nitrate; and (2) the composition of the bulk sample matrix. Emissions from Ba(II) correlated inversely with the plasma electron density, which in turn was dependent upon the percent sand in a sand/soil mixture. The analytical results obtained here show that a field-screening instrument based on LIBS would be useful for the initial screening of soils contaminated with Pb and Ba.

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Identification of 20 polymer types by means of laser-induced breakdown spectroscopy (LIBS) and chemometrics

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-021-03622-y ◽

2021 ◽

Author(s):

Zuzana Gajarska ◽

Lukas Brunnbauer ◽

Hans Lohninger ◽

Andreas Limbeck

Keyword(s):

Near Infrared ◽

Laser Energy ◽

Real Life ◽

Discrimination Performance ◽

Laser Induced Breakdown Spectroscopy ◽

Forward Selection ◽

Experimental Conditions ◽

Breakdown Spectroscopy ◽

Laser Induced Breakdown ◽

Cluster Purity

AbstractOver the past few years, laser-induced breakdown spectroscopy (LIBS) has earned a lot of attention in the field of online polymer identification. Unlike the well-established near-infrared spectroscopy (NIR), LIBS analysis is not limited by the sample thickness or color and therefore seems to be a promising candidate for this task. Nevertheless, the similar elemental composition of most polymers results in high similarity of their LIBS spectra, which makes their discrimination challenging. To address this problem, we developed a novel chemometric strategy based on a systematic optimization of two factors influencing the discrimination ability: the set of experimental conditions (laser energy, gate delay, and atmosphere) employed for the LIBS analysis and the set of spectral variables used as a basis for the polymer discrimination. In the process, a novel concept of spectral descriptors was used to extract chemically relevant information from the polymer spectra, cluster purity based on the k-nearest neighbors (k-NN) was established as a suitable tool for monitoring the extent of cluster overlaps and an in-house designed random forest (RDF) experiment combined with a cluster purity–governed forward selection algorithm was employed to identify spectral variables with the greatest relevance for polymer identification. Using this approach, it was possible to discriminate among 20 virgin polymer types, which is the highest number reported in the literature so far. Additionally, using the optimized experimental conditions and data evaluation, robust discrimination performance could be achieved even with polymer samples containing carbon black or other common additives, which hints at an applicability of the developed approach to real-life samples. Graphical abstract

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On-Line Monitoring of Laser Cleaning of Limestone by Laser-Induced Breakdown Spectroscopy and Laser-Induced Fluorescence

Applied Spectroscopy ◽

10.1366/0003702971941944 ◽

1997 ◽

Vol 51 (8) ◽

pp. 1125-1129 ◽

Cited By ~ 91

Author(s):

I. Gobernado-Mitre ◽

A. C. Prieto ◽

V. Zafiropulos ◽

Y. Spetsidou ◽

C. Fotakis

Keyword(s):

Elemental Composition ◽

Diagnostic Technique ◽

Laser Induced Fluorescence ◽

Laser Cleaning ◽

Laser Induced Breakdown Spectroscopy ◽

Cleaning Process ◽

Experimental Conditions ◽

Breakdown Spectroscopy ◽

Laser Induced Breakdown ◽

On Line

The application of laser-induced breakdown spectroscopy (LIBS) to monitor the laser cleaning process of polluted limestone from a historic building is examined. The combination of a Q-switched Nd: YAG pulsed laser with on-line diagnostics by the LIBS technique is shown to be very useful for controlling and characterizing the cleaning process in order to avoid overcleaning. In addition, the coupling of this spectroscopic technique to the cleaning process provides important information about the optimal experimental conditions to be selected for achieving an adequate cleaning procedure. Furthermore, the spectroscopic study of the plasma emission can be used to determine the elemental composition of both the black crust and the underlying stone. The application of LIBS as a diagnostic technique to monitor and control the laser cleaning process of limestone is based on the different elemental composition of the black encrustations covering the stone surface and the underlying stone. On the other hand, a different experimental setup for probing the ablation products by laser-induced fluorescence (LIF), in order to achieve a signal amplification of some atomic emission lines with weak intensity in the LIBS spectrum, is described.

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