研究目的
To improve accuracy and precision of quantitative analysis using laser-induced breakdown spectroscopy (LIBS) by applying the one-point calibration (OPC) method to a Saha-Boltzmann plot.
研究成果
Applying the OPC method to the Saha-Boltzmann plot improved the accuracy, precision, and stability when calculating CF-LIBS parameters, thus reducing the uncertainties of the estimated C concentration. The method showed an uncertainty of less than 0.5% for plasma temperature and Ne, an r2 value of 0.994, and a root mean square relative error (RMSRE) of 8% for C concentration.
研究不足
The efficiency of CF-LIBS may be compromised by uncertainties in the experimental and spectroscopic parameters. The study also notes the challenge of ensuring the plasma is in local thermodynamic equilibrium (LTE) when the acquisition time is much longer than the lifetime of a plasma.
1:Experimental Design and Method Selection
The study used the OPC method on a Saha-Boltzmann plot to calculate plasma temperature and electron density (Ne) for quantitative elemental analyses with CF-LIBS. Two sets of sodium chloride (NaCl) samples were prepared: one with graphite and another with calcium carbonate (CaCO3).
2:Sample Selection and Data Sources
Samples were prepared with varying concentrations of graphite and CaCO3 in a matrix of NaCl, with fixed concentrations of TiO2 and CuSO4 to facilitate calculations.
3:List of Experimental Equipment and Materials
Ocean Optics LIBS2500 system including a 1064 nm Nd-YAG laser, seven spectrometers with a resolution of 0.1 nm, and a CCD type detector.
4:Experimental Procedures and Operational Workflow
Samples were measured in ambient air atmosphere using the LIBS system. For each sample, 120 spectra were acquired, each corresponding to an average of two consecutive laser shots with a 1.5 μs delay-time and a 1 ms gate window.
5:Data Analysis Methods
The lines were identified using NIST database, and the spectra were processed using software R for outlier removal and the calculation of emission peak areas. Calculations of CF-LIBS, OPC factors, plasma temperature, and Ne were carried out in worksheets generated in LibreOffice Calc with the aid of Gnuplot software.
独家科研数据包,助您复现前沿成果,加速创新突破
获取完整内容