Composed of magnesium and silicon oxides in the approximate ratio of 85:15. This is a polar phase used for the chromatography of compounds such as steroids and alkaloids. This activity can be controlled by the activation temperature used.

• Activation temperature 675 °C as used for item 1,12994 gives a highly active form
• Florisil® item 1,12518 activated at 650 °C is a less active material

Physical properties:

Composition: MgO 15,5%, SiO₂ 84,5%, Na₂SO₄ 0,5% (max. 1%)
pH approx.: 8,5
Specific surface area (BET): 300 m²/g
Specific weight: 2,51 g/ml