Determination of inorganic and organic anionic arsenic species in water byion chromatography coupled to hydride generation-inductively coupled plasma atomic emission spectrometry
Rt. Gettar et al., Determination of inorganic and organic anionic arsenic species in water byion chromatography coupled to hydride generation-inductively coupled plasma atomic emission spectrometry, J CHROMAT A, 884(1-2), 2000, pp. 211-221
The development of an analytical methodology for the specific determination
of arsenite, arsenate and the organic species monomethylarsonic acid (MMA)
and dimethylarsinic acid (DMA), is described. The method is based on an io
n chromatographic separation, coupled on-line to post-column generation of
the gaseous hydrides by reaction with sodium tetrahydroborate in acidic med
ium. Detection and measurement were performed by inductively coupled plasma
spectrometry operated in the atomic emission mode. Arsenic emission was mo
nitored at 193.7 nm. Different types and sizes of anion-exchange columns, s
ilica and polymeric, were tested using EDTA as eluent. Composition, acidity
and flow-rate of the mobile phase were optimized in order to obtain the re
quired resolution. Complete elution and resolution of the four species was
achieved in about 6 min. Linear calibration curves were obtained in the 0.0
5-2 mu g ml(-1) range for As(III), As(V) and MMA, and between 0.1 and 2.0 m
u g ml(-1) for DMA. The absolute limits of detection for 200-mu l sample in
jections were in the ng range, with DMA the compound measured with less sen
sitivity. Results of the analyses of natural samples, such as river and gro
und waters spiked with the studied species, suggested that analyte recoveri
es might be dependent on the sample composition. (C) 2000 Elsevier Science
B.V. All rights reserved.