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Trace elements often limit phytoplankton growth in the ocean, and the quantification of particulate forms is essential to fully understand their biogeochemical cycling. There is presently a lack of reliable measurements on the trace elemental content of marine particles, in part due to the inadequacies of the sampling and analytical methods employed. Here we report on the development of a series of state-of-the-art trace metal clean methods to collect and process oceanic particulate material in open-ocean and sea ice environments, including sampling, size-fractionated filtration, particle digestions and analysis by magnetic sector inductively coupled plasma–mass spectrometry (ICP–MS). Particular attention was paid to the analysis of certified reference materials (CRMs) and field blanks, which are typically the limiting factor for the accurate analysis of low concentrations of trace metals in marine particulate samples. Theoretical detection limits (3 s of the blank) were low for all 17 elements considered, and varied according to filter material and porosity (sub-ìg L−1 for polycarbonate filters and 1–2 ìg L−1 for quartz and polyester filters). Analytical accuracy was verified using fresh water CRMs, with excellent recoveries noted (93–103%). Digestion efficiencies for various acid combinations were assessed using sediment and plankton CRMs. Using nitric acid only, good recoveries (79–90%) were achieved for Mo, Cd, Ba, Pb, Mn, Fe, Co, Ni, Cu, Zn and Ga. The addition of HF was necessary for the quantitative recovery of the more refractory trace elements such as U, Al, V and Cr. Bioactive elements such as P can also be analysed and used as a biomass normaliser. Our developed sampling and analytical methods proved reliable when applied during two major field programs in both the open Southern Ocean and Antarctic sea ice environments during the International Polar Year in 2007. Trace elemental data are presented for particulate samples collected in both suspended and sinking marine material, and also within sea ice cores.

Item Type:	Refereed Article
Keywords:	Trace elements; Marine particles; Determination; Magnetic sector ICP–MS; Certified reference materials; Southern Ocean
Research Division:	Chemical Sciences
Research Group:	Analytical chemistry
Research Field:	Analytical spectrometry
Objective Division:	Environmental Management
Objective Group:	Marine systems and management
Objective Field:	Measurement and assessment of marine water quality and condition
UTAS Author:	Bowie, AR (Professor Andrew Bowie)
UTAS Author:	Townsend, AT (Associate Professor Ashley Townsend)
UTAS Author:	Lannuzel, D (Associate Professor Delphine Lannuzel)
UTAS Author:	Remenyi, TA (Dr Tom Remenyi)
UTAS Author:	Van Der Merwe, P (Dr Pier van der Merwe)
ID Code:	65168
Year Published:	2010
Web of Science® Times Cited:	65
Deposited By:	Austn Centre for Research in Separation Science
Deposited On:	2010-10-08
Last Modified:	2011-05-12
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