Title of article :
Optical fibre reflectance sensor for the determination and speciation analysis of iron in fresh and seawater samples coupled to a multisyringe flow injection system Original Research Article
Carmen Pons، نويسنده , , Rafael Forteza، نويسنده , , Victor Cerda، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2005
A novel optical fibre reflectance sensor coupled to a multisyringe flow injection system (MSFIA) for the determination and speciation analysis of iron at trace level using chelating disks (iminodiacetic groups) is proposed. Once iron(III) has been retained onto a chelating disk, an ammonium thiocyanate stream is injected in order to form the iron(III)–thiocyanate complex which is spectrophotometrically detected at 480 nm. Iron(III) is eluted with 2 M hydrochloric acid so that the chelating disk is regenerated for subsequent experiments. The determination of total iron is achieved by the on-line oxidation of iron(II) to iron(III) with a suitable hydrogen peroxide stream.
A mass calibration was feasible in the range from 0.001 to 0.25 μg. The detection limit (3sb/S) was 0.001 μg. The repeatability (RSD), calculated from nine replicates using 1 ml injections of a 0.1 mg/l concentration, was 2.2%. The repeatability between five chelating disks was 3.6%. The applicability of the proposed methodology in fresh and seawater samples has been proved.
The proposed technique has been validated by replicate analysis (n = 4) of certified reference materials of water with satisfactory results.
Chelating disk , Seawater , Optical fibre reflectance sensor , Multisyringe flow injection analysis (MSFIA) , Iron , Speciation analysis
Journal title :
Analytica Chimica Acta