On-line solid-phase extraction and multisyringe flow injection analysis of Al(III) and Fe(III) in drinking water.
A new analytical method was developed for on-line monitoring of residual coagulants (aluminium and iron salts) in potable water. The determination was based on a sequential procedure coupling an extraction/enrichment step of the analytes onto a modified resin and a spectrophotometric measurement of a surfactant-sensitized binary complex formed between eluted analytes and Chrome Azurol S. The optimization of the solid phase extraction was performed using factorial design and a Doehlert matrix considering six variables: sample percolation rate, sample metal concentration, flow-through sample volume (all three directly linked to the extraction step), elution flow rate, concentration and volume of eluent (all three directly linked to the elution step). A specific reagent was elaborated for sensitive and specific spectrophotometric determination of Al(III) and Fe(III), by optimizing surfactant and ligand concentrations and buffer composition. The whole procedure was automated by a multisyringe flow injection analysis (MSFIA) system. Detection limits of 4.9 and 5.6 microg L(-1) were obtained for Al(III) and Fe(III) determination , respectively, and the linear calibration graph up to 300 microg L(-1) (both for Al(III) and Fe(III)) was well adapted to the monitoring of drinking water quality. The system was successfully applied to the on-site determination of Al(III) and Fe(III) at the outlet of two water treatment units during two periods of the year (winter and summer conditions).
Vanloot
Pierre
P
Laboratoire de Chimie et Environnement (FRE 2704), Université de Provence - Case 29, 3 place Victor Hugo, 13331 Marseille cedex 3, France.
Branger
Catherine
C
Margaillan
André
A
Brach-Papa
Christophe
C
Boudenne
Jean-Luc
JL
Coulomb
Bruno
B
D000535:Aluminum / Q000032:analysis*; D002138:Calibration; D017022:Flow Injection Analysis; D005618:Fresh Water / Q000032:analysis*; D007501:Iron / Q000032:analysis*; D052616:Solid Phase Extraction; D013057:Spectrum Analysis; D014881:Water Supply / Q000592:standards
D000535:Aluminum; D007501:Iron