Seawater reference material CASS

A typical TXRF spectrum of a seawater sample prepared according to the procedure described here is shown in Fig. 12-29 (obtained from the seawater reference material CASS-1 see Section 12.1.6). 

Fig. 12-29. TXRF spectrum of the seawater reference material CASS-1 using W-excitation. The values are given in /

Fig. 5.11. Preconcentration and elution of trace metals in seawater (reference material (CASS-1). Concentrations it jected are 0.094, 0.23, and 0.018 /ig 1 for Cr, Ni, and Co. Legend lists concentrations in original sample. The sample was injected at time zero, and the eluent was changed to remove the analyte complexes at the time indicated by the arrow. Reproduced from Anal. Chem. [50] with permission of American Chemical Society.

Grasshoff K, Ehrardt M, and Kremling K (1999) Methods of Seawater Analysis, 3rd edn. New York Wiley-VCH. Sharp JH, Carlson CA, Peltzer ET, et al. (2002) Final dissolved organic carbon broad community intercalibration and preliminary use of DOC reference materials. Marine Chemistry 78(4) 171-184. 

Accelerator mass spectrometry (AMS) is useful to measure extremely low-abundance nuclides (isotope ratio of 10 to 10 relative to its stable isotope), such as Be, C, A1, C1, " Ca, and I, in natural samples. Small amounts of C and T can be measured by AMS on mg size samples of carbon and iodine extracted from 500-ml seawater samples (Povinec et al. 2000). Neutron activation analysis (NAA), radiochemical neutron activation analysis (RNAA), and inductively coupled plasma mass spectrometry (ICP-MS) are useful for the determination of ultra-trace Th and U in geological and cosmochemical samples, and for determination of the concentration of Pu and Pu. Reference marine-biological samples are necessary to test the performance of the analytical methods employed in surveying and monitoring radioactive materials in the sea. An ocean shellfish composite material containing 0.1% w/w Irish Sea mussel, 12% w/w White Sea mussel, and 87.9% w/w Japan Sea oyster has been prepared as the NIST SRM 4358 (The National Institute of Standards and Technology, SRM) in the natural-matrix, environmental-level radioactive SRM series (Altzitzoglou 2000). This NIST SRM 4358 sample will be useful for the determination of the activity of K, Cs, Pb, Ra, Th, and Am. 

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