Rapid identification of Sr on surfaces of metals, porous medium, transparent materials using single-shot laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) and principal component analysis (PCA) were applied to the classification of LIBS spectra from gold ores prepared as pressed pellets from pulverized bulk samples. For each sample, 5000 single-shot LIBS spectra were obtained. Although the gold concentrations in the samples were as high as 7.7 µg/g, Au emission lines were not observed in most single-shot LIBS spectra, rendering the application of the usual ensemble-averaging approach for spectral processing to be infeasible. Instead, a PCA approach was utilized to analyze the collection of single-shot LIBS spectra. Two spectral ranges of 21 nm and 0.15 nm wide were considered, and LIBS variables (i.e., wavelengths) reduced to no more than three principal components. Single-shot spectra containing Au emission lines (positive spectra) were discriminated by PCA from those without the spectral feature (negative spectra) in a spectral range of less than 1 nm wide around the Au(I) 267.59 nm emission line. Assuming a discrete gold distribution at very low concentration, LIBS sampling of gold particles seemed unlikely; therefore, positive spectra were considered as data outliers. Detection of data outliers was possible using two PCA statistical parameters, i.e., sample residual and Mahalanobis distance. Results from such a classification were compared with a standard database created with positive spectra identified with a filtering algorithm that rejected spectra with an Au intensity below the smallest detectable analytical LIBS signal (i.e., below the LIBS limit of detection). The PCA approach successfully identified 100% of the data outliers when compared with the standard database. False identifications in the multivariate approach were attributed to variations in shot-to-shot intensity and the presence of interfering emission lines.

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Femtosecond Laser Machining of Silica and Transparent Materials

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.525.128 ◽

2014 ◽

Vol 525 ◽

pp. 128-132 ◽

Cited By ~ 2

Author(s):

M. Yu. Babiy ◽

S. S. Golik ◽

A. V. Kolesnikov ◽

F. G. Bystrov

Keyword(s):

Femtosecond Laser ◽

Focal Spot ◽

Optical Breakdown ◽

Laser Induced Breakdown Spectroscopy ◽

Laser Machining ◽

Practical Applications ◽

Breakdown Spectroscopy ◽

Laser Induced Breakdown ◽

Laser Spark ◽

Transparent Materials

Recently, interest in the study of processes occurring in the optical breakdown on the surface of solid targets associated with the increasing number of practical applications of the laser spark, such as laser induced breakdown spectroscopy and micro-and nanomaterials processing. One of the most important tasks - to reduce the diameter of the focal spot, because the size of the modifications directly related to it. However, it is not the only problem faced by the transition to sub-micron range modifications.

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Review: Applications of single-shot laser-induced breakdown spectroscopy

Spectrochimica Acta Part B Atomic Spectroscopy ◽

10.1016/j.sab.2010.01.006 ◽

2010 ◽

Vol 65 (3) ◽

pp. 185-191 ◽

Cited By ~ 89

Author(s):

Anna P.M. Michel

Keyword(s):

Laser Induced Breakdown Spectroscopy ◽

Single Shot ◽

Breakdown Spectroscopy ◽

Laser Induced Breakdown

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Laser‐induced breakdown spectroscopy applied to the rapid identification of different types of polyethylene used for toy manufacturing

Journal of Chemometrics ◽

10.1002/cem.3248 ◽

2020 ◽

Vol 34 (12) ◽

Cited By ~ 1

Author(s):

Vinicius Câmara Costa ◽

Fabíola Manhas Verbi Pereira

Keyword(s):

Rapid Identification ◽

Laser Induced Breakdown Spectroscopy ◽

Breakdown Spectroscopy ◽

Different Types ◽

Laser Induced Breakdown

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Rapid Identification of Kudzu Powder of Different Origins Using Laser-Induced Breakdown Spectroscopy

Sensors ◽

10.3390/s19061453 ◽

2019 ◽

Vol 19 (6) ◽

pp. 1453 ◽

Cited By ~ 5

Author(s):

Fei Liu ◽

Wei Wang ◽

Tingting Shen ◽

Jiyu Peng ◽

Wenwen Kong

Keyword(s):

Discriminant Analysis ◽

Chinese Medicine ◽

Rapid Identification ◽

Laser Induced Breakdown Spectroscopy ◽

Analysis Model ◽

Full Spectrum ◽

Breakdown Spectroscopy ◽

Characteristic Wavelength ◽

Laser Induced Breakdown ◽

Different Origins

The rapid identification of kudzu powder of different origins is of great significance for studying the authenticity identification of Chinese medicine. The feasibility of rapidly identifying kudzu powder origin was investigated based on laser-induced breakdown spectroscopy (LIBS) technology combined with chemometrics methods. The discriminant models based on the full spectrum include extreme learning machine (ELM), soft independent modeling of class analogy (SIMCA), K-nearest neighbor (KNN) and random forest (RF), and the accuracy of models was more than 99.00%. The prediction results of KNN and RF models were best: the accuracy of calibration and prediction sets of kudzu powder from different producing areas both reached 100%. The characteristic wavelengths were selected using principal component analysis (PCA) loadings. The accuracy of calibration set and the prediction set of discrimination models, based on characteristic wavelengths, is all higher than 98.00%. Random forest and KNN have the same excellent identification results, and the accuracy of calibration and prediction sets of kudzu powder from different producing areas reached 100%. Compared with the full spectrum discriminant analysis model, the discriminant analysis model based on the characteristic wavelength had almost the same discriminant effects, and the input variables were reduced by 99.92%. The results of this research show that the characteristic wavelength can be used instead of the LIBS full spectrum to quickly identify kudzu powder from different producing areas, which had the advantages of reducing input, simplifying the model, increasing the speed and improving the model effect. Therefore, LIBS technology is an effective method for rapid identification of kudzu powder from different habitats. This study provides a basis for LIBS to be applied in the genuineness and authenticity identification of Chinese medicine.

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