Microtechniques for the determination of nanomolar concentrations of trace elements in ≤ 10 ml of sediment porewater

Microtechniques were incorporated with trace metal clean techniques to determine nanomolar concentrations of Ag, Cd, Co, Cu, Fe, Ni, Pb and Zn in small (2–10 ml) aliquots of sediment porewater. This involved a liquid-liquid preconcentration with organic chelators (APDC and DDDC) coupled with analyses by graphite furnace atomic absorption spectrometry. The preconcentration was quantitative with recovery efficiencies between 96% and 100% and calculated extraction efficiencies between 90% and 104%. Procedural blanks were 0.95% of the Ag, 0.33% of the Cd, 0.24% of the Cu, 0.12% of the Ni, and ≤0.05% of the Co, Fe, Pb, and Zn concentrations in 10 ml aliquots of an internal reference porewater material. Therefore, these techniques are suitable for measuring ambient concentrations of trace metals in sediment porewater.