A MECHANIZED SYSTEM FOR THE DETERMINATION OF LOW-LEVELS OF QUICKLY REACTING ALUMINUM IN NATURAL-WATERS

A continuous flow system has been connected to a graphite furnace atom ic absorption spectrometer. The system is used to determine low levels of ''quickly reacting Al'' (Al-qr) in natural waters. In the flow sys tem, aluminium reacts with oxine for 2.3 s and the formed complex is t hen extracted into toluene. Iron interference is minimized with a mask ing buffer present in the reagent. Via a simple interface, the toluene extract is introduced into the graphite tube. Good repeatabilities (R .S.D. ca. 2%, n = 10) were obtained, both for standard solutions and f or natural waters. The detection limit is < 0.5 mu g l(-1), and the sa mple throughput using 3 injections/sample, is ca. 10 samples h(-1). Th e system has been used for determining Al-qr in tap water, and is well suited for aluminium fractionation in near-neutral waters.