An ion-pair reversed-phase HPLC-fluorimetric system for ultratrace determination of aluminium with salicylaldehydebenzoylhydrazone

An ion-pair HPLC fluorimetric determination of Al(III) at trace level has been developed, with salicylaldehydebenzoylhydrazone (SAB) as a precolumn reagent. The highly fluorescent AlSAB chelate (lambda(ex) 390.8 nm, lambda(em) 458.1 nm) is separated on a LiChroCART RP-18 column with an eluent consisting of 3.1 x 10(-)m tetrabutylammonium bromide, 1 x 10(4)m disodium EDTA and 5 x 10(-3)m sodium acetate in aqueous 42% w/w acetonitrile solution. The detection limit for Al is 1.5nM (40 pg/ml) in a 100-mul injection. The spectrophotometric detection limit at 390 nm is 0.3 ng/ml for 0.005 full-scale absorbance range. The selectivity is excellent and the method is useful for routine quality-control applications, such as determination of Al in tap water and in alkali pellets (LiOH, NaOH and KOH).