Table 2

Procedure used for 5-step Tessier sediment extractions.

Targeted Fraction
Method

1. Exchangeables
8 mL 1.0 M MgCl2 adjusted to pH = 5–7
1 hr at room temperature

2. Carbonates
8 mL 1.0 M sodium acetate adjusted to pH = 5 with acetic acid
5 hrs at room temperature

3. Fe and Mn oxides
10 mL 0.04 M Hydroxylamine HCl in 25% (v/v) acetic acid
6 hrs at 96°C

4. Organics/Sulfides
3 mL 30% H2O2 adjusted to pH 2 with HNO3
2 hrs at 85°C
3 mL 30% H2O2 adjusted to pH 2 with HNO3
2 hrs at 85°C
Cool. At room temperature add 5 mL of 3.2 N ammonium acetate in 20% (v/v) HNO3, dilute to 20 mL and agitate an additional 30 minutes

5. Residual
Microwave digestion [99]

Koretsky et al. Geochemical Transactions 2006 7:11   doi:10.1186/1467-4866-7-11