Fast quantitative determination of platinum in liquid samples by laser-induced breakdown spectroscopy

This paper describes the effects of laser pulse rate and solution flow rate on the determination of lithium at high pressure for water and 2.5% sodium chloride solutions using laser-induced breakdown spectroscopy (LIBS). Preliminary studies were performed with 0–40 mg L−1 Li solutions, at ambient pressure and at 210 bar, and in static and flowing (6 mL · min−1) regimes, for a combination of four different measurement conditions. The sensitivity of calibration curves depended on the pressure and the flow rate, as well as the laser pulse rate. The sensitivity of the calibration curve increased about 10% and 18% when the pressure was changed from 1 to 210 bar for static and flowing conditions, respectively. However, an effect of flow rate at high pressure for both 2 and 10 Hz laser pulse rates was observed. At ambient pressure, the effect of flow rate was negligible, as the sensitivity of the calibration curve decreased around 2%, while at high pressure the sensitivity increased around 4% when measurements were performed in a flow regime. Therefore, it seems there is a synergistic effect between pressure and flow rate, as the sensitivity increases significantly when both changes are considered. When the pulse rate is changed from 2 to 10 Hz, the sensitivity increases 26–31%, depending on the pressure and flow conditions. For lithium detection limit studies, performed with a laser pulse energy of 2.5 mJ, repetition rate of 10 Hz, gate delay of 500 ns, gate width of 1000 ns, and 1000 accumulations, a value around 40 µg L−1 was achieved for Li solutions in pure water for all four measurement conditions, while a detection limit of about 92 µg L−1 was determined for Li in 2.5% sodium chloride solutions, when high pressure and flowing conditions were employed. The results obtained in the present work demonstrate that LIBS is a powerful tool for the determination of Li in deep ocean conditions such as those found around hydrothermal vent systems.

Section: Introductionmentioning

confidence: 99%

Detection of Low Lithium Concentrations Using Laser-Induced Breakdown Spectroscopy (LIBS) in High-Pressure and High-Flow Conditions

Raimundo¹,

Angel

2021

“…As the plasma cools, each ion in the plasma emits characteristic light which is collected to form a spectrum representing the elements present in the sample. 5 The advantage of LIBS is that it can be done with little to no sample preparation and analytical data can be collected in near real time in many sample phases-including gases, 6 liquids, [7][8][9] solids, 10 and aerosols. 11,12 Laser-induced breakdown spectroscopy technology has been applied [13][14][15][16] in the past to solid salt samples that have been drawn from a melt.…”

Section: Introductionmentioning

confidence: 99%

Laser-Induced Breakdown Spectroscopy (LIBS) Measurement of Uranium in Molten Salt

Williams

Phongikaroon

2018

In this current study, the molten salt aerosol-laser-induced breakdown spectroscopy (LIBS) system was used to measure the uranium (U) content in a ternary UCl-LiCl-KCl salt to investigate and assess a near real-time analytical approach for material safeguards and accountability. Experiments were conducted using five different U concentrations to determine the analytical figures of merit for the system with respect to U. In the analysis, three U lines were used to develop univariate calibration curves at the 367.01 nm, 385.96 nm, and 387.10 nm lines. The 367.01 nm line had the lowest limit of detection (LOD) of 0.065 wt% U. The 385.96 nm line had the best root mean square error of cross-validation (RMSECV) of 0.20 wt% U. In addition to the univariate calibration approach, a multivariate partial least squares (PLS) model was developed to further analyze the data. Using partial least squares (PLS) modeling, an RMSECV of 0.085 wt% U was determined. The RMSECV from the multivariate approach was significantly better than the univariate case and the PLS model is recommended for future LIBS analysis. Overall, the aerosol-LIBS system performed well in monitoring the U concentration and it is expected that the system could be used to quantitatively determine the U compositions within the normal operational concentrations of U in pyroprocessing molten salts.

“…In addition, the formation of bubbles on the static surface influenced the repeatability of the results. Barreda et al 10 also performed work using a static surface, and noted that the shot-to-shot frequency is low due to the time required for the liquid surface to calm between shots.…”

Section: Introductionmentioning

confidence: 99%

Elemental Detection of Cerium and Gadolinium in Aqueous Aerosol Using Laser-Induced Breakdown Spectroscopy

Williams

Phongikaroon

2016

Laser-induced breakdown spectroscopy (LIBS) was used to detect and measure the concentrations of Ce and Gd in aqueous aerosol solutions. A total of 36 standards, with concentrations of Ce and Gd ranging from 100 parts per million (ppm) to 10 000 ppm, were made to explore the relationship between them. In this study, a Collison nebulizer with an argon carrier gas was used to generate the aerosol droplets. For each liquid sample, ten repetitions of 200 laser shots each were recorded. The percent relative standard deviations (%RSD) were on an average of 7.5% between the ten different sample repetitions. Due to the close proximity of the Ce and Gd lines, it was challenging to identify peaks with low interferences. However, several lines were identified, calibration curves were constructed, and the best curves were generated using the 457.228 nm line for Ce and the 409.861 nm line for Gd. The LODs for these curves were calculated to be 209.7 ppm and 216.4 ppm for the Ce line and Gd line, respectively.