INDUCED BREAKDOWN SPECTROSCOPY; QUANTITATIVE-ANALYSIS; PULSE; HELIUM; LIBS; CONFIGURATION; MICROANALYSIS; ENHANCEMENT; DEUTERIUM; NM

An experimental study is performed on the time-dependent intensity variations of Zn emission focusing on the triplet (Zn I 481.0 nm) and singlet (Zn I 636.2 nm) emission lines induced under three experimental conditions. A single nanosecond (ns) Nd:YAG laser in standard laser-induced breakdown spectroscopy(LIBS) setup is employed for the investigation of direct shock wave-induced emission characteristics with N-2 ambient gas at 0.4 kPa and the different effects of He ambient gas at 2 kPa. An additional two-laser system consisting of ns and picosecond (ps) lasers in an orthogonal setup is used to study the exclusive role of a He-assisted excitation (HAE) process for the generation of those two Zn emission lines. The results of this study consistently exhibit the dominant triplet emission over the singlet emission marked by initial maximum intensity ratios of 8 and 12 obtained from the experiments using a single-laser setup in N-2 and He ambient gases, respectively, indicating the significant contribution of the HAE mechanism to the enhanced and longer lasting Zn emission in He gas. The experiment using the special two-laser setup further demonstrates the exclusive role of the HAE process in the Zn emission featuring an even markedly higher triplet/singlet intensity ratio of 22. Thus, the results of this study suggest the possibly more general nature of dominant triplet emission phenomena previously found in laser-induced He and Ca emission spectra. (C) 2017 The Japan Society of Applied Physics

Laser-induced breakdown spectroscopy; Rare earth elements; Aqueous solution; Surface-enhanced;RARE-EARTH-ELEMENTS; QUANTITATIVE-ANALYSIS; ACCURACY IMPROVEMENT; EMISSION; SAMPLES; LIBS; EXTRACTION; LIQUIDS; WATER

Determination of rare earth elements (REEs) plays an important role in the extraction process. In this work, surface-enhanced laser-induced breakdownspectroscopy (SENLIBS) was introduced to detect REEs (lanthanum, cerium, praseodymium, and neodymium elements) in an aqueous solution. The emission lines of La II 394.91 nm, Ce II 418.66 nm, Pr II 422.29 nm, and Nd II 406.10 nm were selected for quantitative analysis by drying the analytical samples on a Zn metal substrate surface and optimizing the experimental parameters. The results showed that the limits of detection (LoDs) for determining La, Ce, Pr, and Nd elements can reach to 0.85, 4.07, 2.97, and 10.98 mu g mL(-1), respectively, which proved that SENLIBS is a feasible method for determining REEs.

laser-induced plasma; plasma spectroscopy; zinc; manganese; gate delay; calibration curve; normalization;INDUCED BREAKDOWN SPECTROSCOPY; FORENSIC ANALYSIS; SELF-ABSORPTION; EMISSION; LIBS; SPECTROMETRY; ABLATION; INKS

Laser-induced plasma spectroscopy is performed to determine the elemental compositions of manganese and zinc in potassium bromide (KBr) matrix. This work has utilized Q-switched Nd: YAG laser installed in LIBS2500plus system at fundamental wavelength. The pelletized sample were ablated in air with maximum laser energy of 650 mJ for different gate delays ranging from 0-18 mu s. The spectra of samples are obtained for five different compositions containing preferred spectral lines. The intensity of spectral line is observed at its maximum at a gate-delay 0.83 mu s and subsequently decayed exponentially with the increasing of gate delay. Maximum signal-to-background ratio of Mn and Zn were found at gate delays of 7.92 and 7.50 mu s, respectively. Initial calibration curves show bad data fitting, whereas the locally normalized intensity for both spectral lines shows enhancement since it is more linearly regressed. This study will give a better understanding in studying the plasma emission and the spectra analysis.

PLASMA-MASS SPECTROMETRY; VACUUM-ULTRAVIOLET; ABLATION; STEEL; COAL

The laser-induced breakdown spectroscopy (LIBS) with a frequency quintupled 213 nmNd:YAG laser was examined to the analysis of trace level of carbon (C) in high-purity metals and its detection and analytical capabilities were evaluated. Though C signal in a wavelength of 247.9 nm, which showed the highest sensitivity of C, could be obtained from Cd, Ti, and Zn ca. 7000 mg kg(-1) C in Fe could not be detected due to the interferences from a lot of Fe spectra. Alternative C signal in a wavelength of 193.1 nm could not be also detected from Fe due to the insufficient laser output energy of the frequency quintupled 213 nm Nd:YAG laser. The depth analysis of C by LIBS was also demonstrated and the C in Cd and Zn was found to be contaminated in only surface area whereas the C in Ti was distributed in bulk. From these results, the frequency quintupled 213 nm Nd:YAG laser, which was adopted widely as a commercial laser ablation (LA) system coupled with inductively coupled plasma mass spectrometry (ICPMS) for trace element analysis in solid materials, could be used for C analysis to achieve simultaneous measurements for both C and trace elements in metals by LIBS and LA-ICPMS, respectively.