Reagents, spikes and standards

FeCk solution (50 g/L Fe) 121 g of FeCb 6H2O are dissolved in 500 mL of 8mol/L HCl. In a 1L glass separating funnel, the Fe is extracted in three times 167 mL of isopropyl ether and the combined extracts are then back extracted with 2 times 250mL of 0.1 mol/L HCl (separate overnight). 

Pb yield tracer (20 g/L Pb) Lead chemicals and standard materials contain Pb. For sufficiently low background levels, carry out a digestion of a certified lead ore such as the sulphide ore galena (Fleer, personal communication). 

KMnO solution (60g/L) 15g of KMn04 are dissolved and made up to 250mL with distilled water. This concentration is just below saturation at 20 C. 

Manganese(II)chloride 40g of MnCl2 5H20 are dissolved and made up to 100 mL with distilled water. This solution is the same reagent as is used for the determination of oxygen (Winkler titration Chapter 4). 

Barium chloride Dissolve 25 g of BaCOs in dilute HCl, dilute gravimetrically with demineralized water to 5 kg. Prepare weighed aliquots, each containing the equivalent of approximately 500 mg of BaCOs, in tightly capped 100 mL polyethylene bottles. 

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