title: Uncertainty contributions to the measurement of dissolved Co, Fe, Pb and V in seawater using flow injection with solid phase preconcentration and detection by collision/reaction cell-quadrupole ICP-MS.
abstract: A flow injection manifold incorporating a solid phase chelating resin (Toyopearl AF-Chelate-650) is reported for the preconcentration of dissolved metals from seawater, with a focus on investigating the effect of the loading pH, wash solution composition and wash time. Cobalt, iron, lead and vanadium have been used as target analytes with contrasting oceanographic behaviour. Quadrupole ICP-MS has been used for detection to make the approach accessible to most laboratories and a collision/reaction cell has been incorporated to minimise polyatomic interferences. Results for the seawater CRM NASS-6 and two GEOTRACES reference materials were in good agreement with the certified/consensus values, demonstrating the suitability of the approach for the determination of trace metals in seawater. The experimental design used allowed a thorough investigation of the uncertainty contribution from each method parameter to the overall expanded uncertainty of the measurement. The results showed that the parameters making the largest contributions were the precision of the peak area measurement and the uncertainty associated with the slope of the calibration curve. Therefore, these are the critical parameters that should be targeted in order to reduce the overall measurement uncertainty. For iron, the wash blank also gave a measureable contribution.
authors.affiliation: Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA, United Kingdom.
authors.forename: Robert
authors.initials: R
authors.lastname: Clough
authors.affiliation: Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA, United Kingdom; Nuclear Research Centre, Negev, PO Box 9001, Beer-Sheva, Israel.
authors.forename: Hagit
authors.initials: H
authors.lastname: Sela
authors.affiliation: Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA, United Kingdom.
authors.forename: Angela
authors.initials: A
authors.lastname: Milne
authors.affiliation: Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA, United Kingdom.
authors.forename: Maeve C
authors.initials: MC
authors.lastname: Lohan
authors.affiliation: Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA, United Kingdom; Erciyes University, Faculty of Science, Chemistry Department, TR 38039 Kayseri, Turkey.
authors.forename: Serife
authors.initials: S
authors.lastname: Tokalioglu
authors.affiliation: Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA, United Kingdom. Electronic address: pworsfold@plymouth.ac.uk.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Worsfold
mesh_terms: D003035:Cobalt / Q000032:analysis; D017022:Flow Injection Analysis / Q000295:instrumentation; D007501:Iron / Q000032:analysis; D007854:Lead / Q000032:analysis; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000295:instrumentation*; D019216:Metals, Heavy / Q000032:analysis*; D012623:Seawater / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000295:instrumentation*; D035501:Uncertainty; D014639:Vanadium / Q000032:analysis
chemical_list: D019216:Metals, Heavy; D014639:Vanadium; D007854:Lead; D003035:Cobalt; D007501:Iron
keywords: Flow injection; Preconcentration; Quadrupole ICP–MS; Seawater; Trace metals