Vapour-phase behaviour of slurries in electrothermal atomic absorption spectrometry

Abstract

The evolution of molecular and atomic vapours during the atomization of slurries has been followed ming an ultraviolet spectrophotometer with diode-array detection. Certified reference materials with an appropriate inorganic matter content were vaporized at 1700 "C, which gave rise to SiO molecules with a structured absorption between 200 and 250 nm. The same slurries, but prepared with HN03, when vaporized at the same temperature produced AI2C2 species. Atomization at 2200 "C led to the fast evolution of SiO and Al species and to a rapid change in spectral behaviour of the vapour phase. Above 280 nm deuterium-arc background correction was effective at reducing non-specific absorption, while at lower wavelengths Zeeman-effect background correction was more effective for the analytical lines in the spectral range of SiO and Al species.

Atomic Absorption, Atomic Emission, and Flame Emission Spectrometry

“…Spectral interferences can be more pronounced in slurry-ETAAS compared with solution analysis, and two separate reports described structured background that may not be corrected if continuum-source background correction is used. Biffi and Tittarelli (496,497) demonstrated an intense structured background absorbance between 200 and 280 nm when samples high in Si or Al are analyzed. Zeeman-effect background correction was satisfactory, but the use of a deuterium-lamp system resulted in a spectral error.…”

Espectrofotometria multicanal e arranjos de fotodiodos

“…No entanto, esforços têm sido feitos no sentido de solucionar esta limitação dos instrumentos comerciais 46 e, paralelamente, vários instrumentos e sistemas multicanais baseados em arranjos lineares de fotodiodos têm sido descritos na literatura, em função das necessidades específicas dos usuários [47][48][49][50][51][52][53][54] . Os detectores de arranjo de diodos têm, naturalmente, amplas aplicações em determinações simultâneas sendo empregados em métodos com parada de fluxo (stopped-flow) 55,56 , cinéticos 57,58 , derivativos 59,60 , quimiométricos 61,62 e técnicas como cromatografia gasosa 63 , espectroeletroquímica 64,65 , espectrometria de absorção atômica 66,67 , de emissão atômica em plasma acoplado indutivamente 9,68 e espectrografia de emissão atômica 69 . Ainda, os espectrofotômetros PDA têm sido também empregados em determinações onde suas propriedades multicanais não são requisitadas 70,71 , ocupando um espaço antes reservado apenas para as fotomultiplicadoras.…”

Identification of molecules in graphite furnace by laser ionization time-of-flight mass spectrometry: sulfur and chlorine containing compounds

“…ETV with a continuous source of radiation and an ultraviolet (UV) multichannel detector spectrometer was employed recently for the systematic study of UV absorption spectra of inorganic compounds. [1][2][3][4][5][6][7][8][9][10][11][12][13] The setup was initially developed by Tittarelli et al, [1][2][3][4] and later improved by Daminelli et al [5][6][7] Investigations of alkaline earth fluorides and chlorides, [8][9][10] indium nitrate and Group 3 halides, 11 sulfides, sulfates and sulfur 12,13 were also carried out with this technique. The main objective of these studies was to identify species responsible for the absorption of the UV radiation.…”