Alumina-A Column Plates for Solid Phase Extraction

Alumina is a typical Lewis acid that does not have two electrons in the center of the aluminum atom, it is a strong polar adsorbent similar to silica gel; It is available in three high activity levels: acidic, basic, and neutral; alumina also has a special effect on the π-electrons of aromatic hydrocarbons; and it is more stable than silica gel under high pH conditions. The main confinement mechanisms are the Lewis acid-base interaction, the polar interaction, and ion exchange.
The acidic properties of Lewis B&M® Alumina-A (pH = 4.5) are enhanced, and the adsorbent is better able to retain electron-rich compounds. In addition, the weak cationic nature of the adsorbent allows it to more easily hold neutral and negatively charged substances (e.g., electrically neutral acids or acidic anions) on the surface when pretreated with an acidic solution, while positively charged substances are not retained as well. The weak ion exchange property also increases the probability of retention of negatively charged substances.