Sulfonylcalixarenetetrasulfonate (SO2CAS) has been examined as a pre-column chelating reagent for ultratrace determination of metal ions by ion-pair reversed-phase high-performance liquid chromatography with spectrophotometric detection. Metal ions were converted into the SO 2CAS chelates in an acetic buffer solution (pH 4.7). The chelates were injected onto a n-octadecylsilanized silica-type Chromolith™ Performance RP-18e column and were eluted using a methanol (50 wt.%)-water eluent (pH 5.6) containing tetra-n-butylammonium bromide (7.0 mmol kg -1), acetate buffer (5.0 mmol kg-1), and disodium ethylendiamine-N,N,N′,N′-tetraacetate (0.10 mmol kg-1). Under the conditions used, Al(III), Fe(III), and Ti(IV) were selectively detected among 21 kinds of metal ions [Al(III), Ba(II), Be(II), Ca(II), Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Ga(III), Hf(IV), In(III), Mg(II), Mn(II), Mo(VI), Ni(II), Pb(II), Ti(IV), V(V), Zn(II), and Zr(IV)]. The detection limits on a 3σ blank basis were 8.8 nmol dm-3 (0.24 ng cm -3) for Al(III), 7.6 nmol dm-3 (0.42 ng cm-3) for Fe(III), and 17 nmol dm-3 (0.80 ng cm-3) for Ti(IV). The practical applicability of the proposed method was checked using river and tap water samples.
ASJC Scopus subject areas
- Analytical Chemistry