Construction of an atomic absorption spectrometer and studies on the formation and evolution of the atomic cloud with electrothermal atomization in a double tungsten coil system

Author(s)

Manassés Zuliani Jora

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 0000-00-00

Examining board members

Celio Pasquini; Francisco Jose Krug; Solange Cadore

• Advisor: Joaquim de Araujo Nobrega; Celio Pasquini

Abstract

Electrothermal atomic absorption spectrometry (ET AAS) is suitable for determination of metals and semimetals with high sensitivity. Among the existing electrothermal atomizers, graphite furnace stands out due to its selectivity, requirement of low volume of sample and low limits of detection (i.e. 'mu'g L-1). Notwithstanding, these atomizers present high cost and requires high power power supply (i.e. above 2 kW) and a cooling system. Alternatively, metallic surfaces have been studied since 1970. Among all metals employed as atomizers in ET AAS studies, tungsten has presented the best results and has found many analytical applications. However, tungsten coil atomic absorption spectrometry (WC AAS) presents several challenges related to understanding the atomic cloud generation and interferences effects. Thus, in this work, a double tungsten coil atomic absorption spectrometer (DWC AAS), with two different configurations was constructed. In one configuration, a detection system based on echelle/intensified charge-coupled device (ICCD) is employed and, in the other, an acousto-optic tunable filter (AOTF)/photomultiplier detection system is used. Both configurations were employed in the atomic cloud generation and evolution studies of Pb and Cr. Furthermore, interferences on the atomic cloud profile of Pb and Cr caused by Na, K, Ca and Mg, at three different concentrations (i.e. 1, 10 and 100 mg L-1), were studied. This study helped to evaluate the effect of condensed and gas phase interferences. Additionally, the equipment was employed to perform measures of surface and gas phase temperatures (AU)

• FAPESP's process: 12/01957-4 - CONSTRUCTION OF AN ATOMIC ABSORPTION SPECTROMETER AND STUDIES ON THE FORMATION AND EVOLUTION OF THE ATOMIC CLOUD WITH ELETROTHERMAL ATOMIZATION IN A DOUBLE TUNGSTEN COIL SYSTEM
• Grantee: Manassés Zuliani Jora
• Support Opportunities: Scholarships in Brazil - Master