Flame atomic absorption determination of manganese in whole blood using solvent extraction into acetone

Whole blood sample (2 mL) is dry ashed and taken up in 3 M hydrochloric acid. The volume is adjusted to 2 mL with water, and 3 mL of saturated calcium chloride solution (previously saturated with acetone) is added. Iron is removed first by solvent extraction from the acid solution with 100 ppm dithizone in acetone. The pH of the aqueous phase is adjusted to 8.0 with 0.2 mL of 0.4 M tris buffer, and the manganese is extracted with dithizone in 2 mL acetone and is measured in the acetone phase at 278.8 nm by atomic absorption spectrometry using an air-acetylene flame. The mean manganese value found for 14 samples was 32 +/- 7 ppb. The detection limit is 2 ppb manganese.