STRATEGIC STUDIES OF SPECTROCHEMICAL ANALYSIS BY HR-CS AAS, LIBS AND RAMAN SPECTROSCOPY

Abstract

It is intended to critically evaluate new sample preparation strategies employing a Conductively Heating Digestion System (CHDS). This equipment will be studied for samples of environmental, energy and food interest. Considering the low relative sensitivity of laser-induced breakdown spectroscopy (LIBS), it is proposed to evaluate an electrical system to generate a spark in the plasma during laser incidence in the establishment of new methods of elemental analysis in samples of difficult ablation such as botanical and biological tissues, plastic packaging. Considering the possibility of analysis of microliters of sample deposited on the surface of a paper (dried matrix spot, DMS), it is planned to develop a minimally invasive method to determine Cu, Mn and Zn in blood (dried blood spot, DBS) by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). This approach will involve in situ sample treatment in the graphite atomizer of the spectrometer. The potentialities of Raman spectroscopy will be explored in the development of simpler and more sustainable quantitative methods of analyses. The equilibrium of phosphoric and phosphorous acids, nitrate, ammonium and urea in aqueous media were studies in order to develop methods for the identification of N species (nitrate, urea, ammonium) and P (phosphate and phosphite) usually present in fertilizer formulations. Also, chemical speciation of phosphate and phosphite will be investigated. All methods will be validated by means of certified reference materials, alternative techniques and/or addition/recovery tests. The main figures of merit such as selectivity, recovery, linearity, precision, accuracy and limits of detection and quantification will be determined by using well-known statistical tests. (AU)