Division 5.1 F1F2

Hexane or mixture of alkanes of b.p. interval 65 to 70 °C, distilled with rectifying column. Hexane may be replaced by iso-octane (2,2,4-trimethyl pentane in chromatography grade), provided that comparable precision values are achieved. The residue after evaporation of 100 ml of solvent may be controlled. Solvents with higher boiling point than n-hexane take longer to evaporate. However, they are preferred due to the toxicity of hexane.