Ag. Howard et Le. Hunt, COUPLED PHOTOOXIDATION HYDRIDE AAS DETECTOR FOR THE HPLC OF ARSENIC COMPOUNDS, Analytical chemistry, 65(21), 1993, pp. 2995-2998
A widely applicable arsenic-specific detection system has been constru
cted for HPLC. The restricted range of compounds which can be detected
by hydride generation atomic absorption spectroscopy (AAS) has been o
vercome by the incorporation of a simple low-power ultraviolet irradia
tion stage. The detector employs an on-line persulfate-mediated photoo
xidation prior to hydride generation, atomization, and measurement by
AAS. The system has been shown to respond to arsenite, arsenate, dimet
hylarsinate, methylarsonate, arsenobetaine, arsenocholine, o- and p-ar
sanilate, phenylarsonate, and tetramethylarsonium ions. Confirmation o
f peak identity is enhanced by comparison of peak areas with and witho
ut photooxidation. Absolute detection limits (3 sigma) for the system
are typically ca. 50 pg of arsenic corresponding to 0.3 mug of As/L us
ing a 166-muL injection. Reproducibilities lie within the range +/- 1.
1-4.2%.