Summary of Activated Alumina Content

1. Basic Product Information

• ‌Product Name‌: Activated Alumina (Alumina, Activated)

• ‌Molecular Formula & Weight‌:

• Formula: Al₂O₃

• Molecular Weight: 101.96

2. Physical & Chemical Properties

• ‌Appearance‌: White powder

• ‌Solubility‌: Almost insoluble in water, organic solvents, acids, and alkalis

• ‌Melting Point‌: 2030°C

• ‌Specific Gravity‌: 3.97

• ‌pH Value‌: Alkaline (pH 9.0–11.0 in a 100 g/L aqueous solution at 25°C)

3. Product Characteristics & Applications

• ‌Adsorption Capacity‌: Strong absorption capability for water and gases, making it useful as an adsorbent, desiccant, and catalyst (especially for dehydration reactions).

• ‌Classification & Suitability‌:

• Activated alumina is categorized into acidic (pH 4), alkaline (pH 9), and neutral (pH 7.5) types.

• This product is alkaline alumina, suitable for separating alkaloids, steroids, terpenes, and similar compounds.

• ‌Chromatography Applications‌:

• Due to its high activity, activated alumina is widely used in chromatography for efficient separation.

• It serves as a carrier for adsorption and reverse-phase chromatography, particularly for neutral and basic substances.

• The activity level of alumina can be adjusted based on moisture content, classified into five stages (I to V), with decreasing activity.

4. Usage & Purification

• ‌Pre-Treatment‌: In catecholamine analysis, activated alumina requires purification to improve recovery rates.

• ‌Purification Steps‌:

1. 1.Stir 50 g of alumina with 2N HCl at 90–100°C for 70 minutes.

2. 2.Allow settling, decant, and repeat until the supernatant becomes clear and colorless.

3. 3.Cool, rinse until pH reaches 4.

4. 4.Filter, dry, and store in a desiccator.

5. References & Source

• This summary is based on information from http://www.jinpanlab.cn/archives/2857.html and related literature.