| Summary: | Maintenance and Update Frequency: asNeeded Statement: 1. Sample collection All sample tissue and faecal matter were stored in individual 50 ml polycarbonate screw cap bottles, preserved in >70% ethanol and frozen at -20°C until analyses. 2. Analysis of the trace element concentration Samples were dried at 60°C until constant weight was attained. Subsequently they were crushed using an acid-cleaned pipette tip and shaken vigorously to homogenise the samples. Digestion of 2–100 mg subsamples were performed in acid-cleaned 15 ml Teflon® perfluoroalkoxy (PFA) vials (Savillex, Minnetonka, MN, USA) by adding 1 ml of concentrated nitric acid and 0.125 ml of hydrogen peroxide (all Ultrapure, Seastar Baseline®, Choice Analytical). The samples were then heated at 125°C for 8 hours on Teflon coated digestion hotplate, housed in a bench-top fume hood coupled with HEPA filters to ensure clean input air (Digiprep, France). Identical procedures were applied to blanks (n = 6) and to two certified referenced materials (n = 5) (DORM-3 fish protein; National Research Council, Ottawa, Canada; and NIST 1566a oyster tissue; National Institute of Standards and Technology, Gaithersburg, Maryland, USA). Certified materials, blanks and samples were resuspended in 10–100 mL of 10% v:v nitric acid (Ultrapure, Seastar Baseline) and analysed by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) (Finnigan MAT ELEMENT 1 Bremen Germany), following methods described in Cullen and Sherrell (1999) and Townsend (2000). 3. Analysis of carbon All glass- and metal-ware in contact with the carbon samples were pre-combusted at 450°C for 12 hours. Subsamples (2–100 mg) of dried faecal matter were placed in 13 mm diameter silver capsules (Sercon, Australia) and carbon content was then determined at the Central Science Laboratory, University of Tasmania, using a Thermo Finnigan EA 1112 Series Flash Elemental Analyser (estimated precision ~1%). Note, for some samples the date of collection was not recorded. Credit Antarctic Climate ...
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