A field aluminium speciation method to study the aluminium hazard in water

The toxicity of aluminium is governed by its bioavailability. Therefore, the speciation of aluminium in drinking water becomes of prime importance to understand its fate and the population exposure, and to develop guidelines for the concentration levels. At Health Canada, a field speciation method has been developed to perform on-site speciation followed by measurement of Al in the laboratory. The following species are generated: 1) total recoverable; 2) total acid-leacheable; 3) total dissolved; 4) dissolved extracted; and 5) dissolved non extracted. The field extractions are performed by percolation through chelation columns, which are later processed in the laboratory. Aluminium determinations can then be performed by numerous methods, such as by Inductively Coupled Plasma Mass Spectrometry (ICPMS), Graphite Furnace Atomic Absorption Spectrometry (GFAAS) or Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Examples of results for raw or treated/ distributed surface waters, as well as for groundwaters, are used to illustrate the validity of the method, and the importance of considering aluminium speciation in characterizing the aluminium hazard in water.