A simple reverse flow-injection (rFIA) manifold for the direct determination of aluminum in drinking water is
proposed. This rapid and sensitive method is based on the formation of an Al3 complex with salicylaldehyde
picolinoylhydrazone (SAPH), which shows a maximum blue-green fluorescence (lex/384 nm, lem/ 468 nm) at pH
5.4. Operative conditions both for batch and rFIA procedures were investigated including reagent concentration, buffer
solutions, injection loop, reacting coil and wavelengths used for the fluorimetric detection. The tolerance limits of
foreign ions have been also evaluated, before and after the addition of masking agents. The reverse flow-injection
procedure allows determination of Al3 at ppb level (LOD: 1.9 mg l1) within a working range of 5/30 mg l1. The
proposed method was successfully employed for the determination of Al3 in several commercial drinking, soft
drinking (as certified reference material), and tap water samples.