Study of Matrix Effects in Laser Plasma Spectroscopy by Combined Multifiber Spatial and Temporal Resolutions

Abstract

Understanding the matrix effects in laser plasma spectroscopy is of considerable importance, since these effects actually limit the performance of the method. Thus, a new multifiber imaging spectrometer, coupled with an ICCD detection system, was developed and applied to this task. A special sample holder which enables simultaneous observation of single-shot plasmas through eight optical fibers was constructed. The fibers collect the emission at several locations from single-shot plasma, perpendicularly to its expansion axis. In this way, high-resolution spectra of the analyte and the matrix are simultaneously obtained with spatial and temporal resolutions. Results on investigation of matrix effects in analysis of Pb in natural soils, using this setup, are reported. The matrix effect due to the sand content in the examined samples is presented, and explanations are suggested. It was found that the optimum location in the plasma for spectral analysis depends on analyte concentration in such a way that, at higher concentration ranges, the spectra should be measured closer to the surface. A clear global optimum was observed for analyte signal as a function of location and time, indicating the best experimental conditions. The matrix dependence of that optimum is addressed. The spatial distribution of the internal plasma temperature and the related matrix effects are also discussed.

Comparison of univariate and multivariate calibration for the determination of micronutrients in pellets of plant materials by laser induced breakdown spectrometry

“…In laser induced breakdown spectrometry (LIBS), the excitations of atomic, ionic and molecular species are promoted in a plasma by a short pulse of high energy radiation generated by a laser focused on a sample [1,2]. Several applications of LIBS for the analysis of elemental composition are focused on metallurgical samples [3].…”

LIBS Detection of Explosives in Traces

“…However, although displaying high sensitivity, LIBS suffers from several disadvantages such as the relatively large shot-to-shot signal variability [3] and matrix effects [4] that can lead to a preferential ablation of elements from a complex sample and to non-linearity in emission spectra, as well as a limited selectivity; several shortcomings that may disrupt both qualitative and quantitative compositional determinations from residues [5,6].…”

Complexation and Coordination Studies of Micelle Forming Surfactant Sodium Lauryl Sulphate with Eriochrome Azurol B.

“…The interesting property of the aggregates formed is their ability to form colored complexes with various cations.When the charge on the surfactant micelle is opposite to that of the indicator ions, the greatest is the color change observed. Reactions of triphenylmethane dyes with some heavy metal ions have been a subject matter of study by several workers (4)(5)(6)(7)(8).Another advantage is that the determination of microamounts of metal ions can be done with much higher sensitivity in the presence of these long chain quaternary salts. Composition of dye-surfactant complex is determined by adding varying concentration of surfactants to the dye solutions.…”