A mechanized system for the determination of low levels of quickly reacting aluminium in natural waters

A continuous flow system has been connected to a graphite furnace atomic absorption spectrometer. The system is used to determine low levels of “quickly reacting Al” (Alqr) in natural waters. In the flow system, aluminium reacts with oxine for 2.3 s and the formed complex is then extracted into toluene. Iron interference is minimized with a masking 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 for natural waters. The detection limit is < 0.5 μg l−1, and the sample throughput using 3 injections/sample, is ca. 10 samples h−1. The system has been used for determining Alqr in tap water, and is well suited for aluminium fractionation in near-neutral waters.