Speciation of arsenic oxides using laser desorption/ionization time-of-flight mass spectrometry.
Positive and negative ion mass spectra of arsenic trioxide (As2O3) and arsenic pentaoxide (As2O5) have been obtained by single-step laser desorption/ionization time-of-flight mass spectrometry. Pulsed UV radiation at 266 nm was used for the simultaneous desorption and ionization of the solid sample. High-mass cluster ions that are unique to the oxidation state of each oxide sample appear in the negative ion mass spectra. The As2O3 produces As3O5-, while the As2O5 yields As3O8-. The formation of unique negative cluster ions presents the capability for arsenic oxidation state speciation by laser desorption/ionization mass spectrometry. The ability of time-of-flight mass spectrometry to examine the relative amounts of each arsenic oxide present in a series of mixtures is discussed. Application of our speciation technique to a model incinerator sample is demonstrated.
Department of Chemistry, University of California, Davis 95616, USA.
T M
TM
Allen
D Z
DZ
Bezabeh
C H
CH
Smith
E M
EM
McCauley
A D
AD
Jones
D P
DP
Chang
I M
IM
Kennedy
P B
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Kelly
D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet
D001152:Arsenicals; D010087:Oxides; C042120:arsenic pentoxide; D000077237:Arsenic Trioxide