Evaluation of the direct solid sampling high-resolution continuum source atomic absorption spectrometry for analysis of difficult samples

Abstract

Elemental analyses by spectrometric techniques are commonly carried out employing direct introduction of liquid samples. Solid samples must then be converted into clear solutions. Conventional procedures based on wet and dry ashing are most commonly used for preparation of solid samples. Nevertheless, they are considered laborious, time consuming, susceptible to sample contamination and analyte losses, demand large amounts of reagents and energy, and may generate noteworthy volume of hazardous residues. The direct solid sampling presents advantages over introduction of liquid samples. This proposal deals with evaluation and application of the direct solid sampling in high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) to analysis of relevant samples to some strategic economic sectors in Brazil such as energy, environment, agriculture and beauty & care. Among applications are the determination of Mo and Co in biomass, and soil; Cd, Cr, Ni and Pb in cosmetics; Al, Fe and P in solar grade silicon. Certified reference materials, alternative techniques, or addition/recovery tests should be used for methods evaluation and validation. Well-established statistic tests will help to assess the main figures of merit (selectivity, recovery coefficients, linearity, precision, accuracy, limits of detection and quantification). (AU)