Use Of SiliaBond® TMA Acetate
Strong anion exchangers (SAX) have been widely used in both chromatography and ion exchange SPE to selectively bind acidic drugs and/or analytes. In particular, weakly acidic compounds can be effectively extracted as those types of sorbents retain a permanent positive charge across the pH range. Most commercially available silica-based SAX sorbents are produced with a high selectivity chloride counter ion which reduced retention of acidic drugs when compared with lower selectivity counter ions such as acetate. Therefore, users traditionally perform the exchange of the chloride ion prior to sample loading. This process can be time consuming and the exchange may be incomplete.
To this end, SiliCycle has developed SiliaBond® TMA Acetate (Si-SAX-2), a strong anion exchanger sorbent with a low selectivity acetate counter ion already in place. Typical loading is 1.0 mmol/g which is higher than other equivalents available on the market.
This sorbent retains more favorably acidic compounds with pKa < 5, such as carboxylic acid. This property can be used in synthetic chemistry applications to selectively purify acidic compounds or remove acidic impurities from reaction mixtures.