Validation of a Portable Flow Injection-Chemiluminescence (FI-CL) Method for the Determination of Dissolved Iron in Atlantic Open Ocean and Shelf Waters by Comparison with Isotope Dilution-Inductively Coupled Plasma Mass Spectrometry (ID-ICPMS)

• Published in: Environmental Chemistry
• Main Authors: USSHER Simon J., PETROV Ivan, QUETEL Christophe, WORSFOLD Paul
• Language: English
• Published: CSIRO PUBLISHING 2010
• Subjects: South Atlantic Ocean
• Online Access: https://publications.jrc.ec.europa.eu/repository/handle/JRC53239; https://doi.org/10.1071/EN09092

A blind intercomparison exercise was carried out to validate a well-documented, portable flow injection chemiluminescence (FI-CL) method for the determination of iron in seawater. This was done by the analysis of a variety of filtered Atlantic Ocean samples using FI-CL data and a potential primary method of measurement, isotope dilution-inductively coupled plasma mass spectrometry (ID-ICPMS). To investigate the effect of the seawater matrix at various concentrations of iron, samples were collected at various depths (0-200 m) from different water masses (European Continental Shelf, the South Atlantic Ocean) and filtered through both 0.02 and 0.2 µm pore size filters. The exercise was conducted under controlled conditions using the same bottles transported between laboratories to avoid between-bottle inhomogeneity. The results showed good agreement between the two methods (r2 = 0.82) for dissolved iron over the concentration range 0.15-2.1 nM. Some samples were not in agreement within estimated uncertainties and this was attributed to random errors arising from contamination during sample handling and/or matrix effects (i.e. variable interferences) rather than systematic errors. JRC.D.3 - Knowledge Transfer and Standards for Security