Trace Quantitative and Exploratory Analysis by Multivariate Chemometric Laser Induced Breakdown Spectrometry Applied to Malaria and Radiogeothermic Diagnostics

Abstract

Although UBS provides analysis capability for determining the chemical composition of materials via their atomic and ionic emission in a minimally non-invasive manner, its utility for rapid trace quantitative analysis is limited for laser plasma in air and atmospheric pressure which are optically thick and the spectra from environmental and biological samples complex. Quantitative analysis via calibration free analysis is therefore not feasible. We may utilize multivariate chemometrics to reduce the spectral complexity and model the spectra for direct trace clement analysis. We did this towards method development for malaria and radiogeothermic diagnostics. The paper outlines our method and presents the results of quantitative characterization of a radiogenically stressed geothermal field using PLS and ANN modeling of As. Cr. Cu. Pb and Ti in rocks and soils based on single shot ablation utilizing both the entire spectrum (200 - I, - 980 nm ) and feature selection as well as the estimated analyte concentrations combined with SIMCA and PCA for exploratory analysis. Due to the speed, low detection limits realized and potential of the method (or molecular spectroscopy. a model for the analysis of trace Zn. Cu. Fe. Se and Mg in blood smears on Nucleopore filter paper has been developed; this constitutes an important step towards rapid analysis and elucidation of the rule of these trace elements and their utility in malaria diagnostics.