Mechanistic characterization of chloride interferences in electrothermal atomization systems

Abstract

A computer-controlled spectrometer with a photodiode array detector has been used for wavelength and temperature resolved characterization of the vapor produced by an electrothermal atomizer. The system has been used to study the chloride matrix Interference on the atomic absorption spectrometrlc determination of manganese and copper. The suppression of manganese and copper atom populations by matrix chlorides such as those of calcium and magnesium Is due to the gas-phase formation of an analyte chloride species followed by the diffusion of significant fractions of these species from the atom cell prior to completion of the atomization process. The analyte chloride species cannot be formed when matrix chlorides with metal-chloride bond dissociation energies above those of the analyte chlorides are the principal entitles present. The results Indicate that multiple wavelength spectrometry used to obtain temperature-resolved spectra Is a viable tool In the mechanistic characterization of Interference effects observed with electrothermal atomization systems.

Continuum source atomic absorption spectrometry and detector technology: A historical perspective

“…The further drawback arising from the sequential read-out of the array can be circumvented by means of a mechanical shutter. At first, linear PDA detectors were used in AAS for the study of broadrange background absorption in the graphite furnace [105,106]. By means of a D 2 lamp as continuum source the wavelength range from 190 nm to 350 nm could be covered with a bandwidth per pixel of a few hundred pm.…”

Direct Determination of Arsenic in Beet Sugar Molasses Using Nickel as Chemical Modifier by Electrothermal Atomic Absorption Spectrommetry

“…12 Finally, the presence of large amounts of chlorine in the gas phase of the atomizer at the atomization stage can facilitate the incomplete dissociation or recombination of analyte chlorides in the gas phase of the graphite furnace at the atomization stage. 13 Therefore, the use of the chemical modifiers is aimed at the elimination of interferences from inorganic chlorides. some chemical matrix modifiers such as NiCl 2 ,nation in previous works.…”

Novel matrix modifier for direct determination of palladium in gold alloy by electrothermal vaporization inductively coupled plasma mass spectrometry

“…The suppression effects of common halide salts of the matrix on the determination of transition elements by ETAAS have been widely discussed. 14 The chemical interactions between the halide salts and the analyte, and the formation of volatile halides with diffusion loss have proved to be vital factors leading to signal suppression. 14 However, using ETV-ICP-MS, a significant enhancement in analytical signals has been reported when halogenated compounds 15 and halide salts 10 were used as modifiers to form metal halides with high volatility.…”

“…14 The chemical interactions between the halide salts and the analyte, and the formation of volatile halides with diffusion loss have proved to be vital factors leading to signal suppression. 14 However, using ETV-ICP-MS, a significant enhancement in analytical signals has been reported when halogenated compounds 15 and halide salts 10 were used as modifiers to form metal halides with high volatility. It is well known that the volatile characteristics of different halide species are dependent on bp values.…”