Solid-phase sediment digestions, analysis

Solid-phase sediment digestions were analyzed in triplicate, with one duplicate digestion and a spike recovery or analysis of reference material every 10 samples. Coefficients of variation (C.V.) for triplicates fell within 0.5-11.5% [n = 60, mean C.V. = 3.6% 2.4% (std)], and spike recoveries were within 90-103% [n = 3, mean = 96% 7%]. Eight replicates of standard reference material [National Institute of Standards and Technology (NIST) Tennessee River sediment, Catalog No. 8406] were within 10% (0.053 0.004 xg/g, C.V = 7.2%) of the recommended value of 0.06 xg/g. A standard reference for Hg in natural water was not available. Typical duplicates of small-volume pore waters (<30 mL) had an average C.V of 30.8% 22% (n = 30). 

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