What is a recommended method for using the Sep-Pak Accell Plus QMA to retain and elute an acidic compound? - WKB124677

ENVIRONMENT

• Sep-Pak Accell Plus QMA
• Method development
• Acid retention

ANSWER

1. Condition your SPE Classic cartridge with 6 -10 hold-up volumes of 100% water.
2. Equilibrate with 6-10 hold-up volumes of your loading conditions (experiment with pHs 5-8 for best ion exchange of target acid). 
3. Load sample (1-5 mL volume is typical but can be higher if sorbent is not overloaded).

The flow should look like droplets (not too fast; maximize contact time with the sorbent); 1 drop per second flow rate.

4. Wash with 3-6 hold-up volumes of buffer pH 5-8 to reinforce the ion exchange of target acid to sorbent.
5. Elute with acidic water (perhaps 5% acetic acid or 1% formic acid) or some combination of acidic water and 50% methanol or acetonitrile.

The recommended elution step volume is 3 cartridge hold-up volumes (you can cut this in half if a reasonable recovery is maximized by optimized elution conditions).

The elution flow should look like droplets (not too fast; maximize contact time with the sorbent); 1 drop per second flow rate.

ADDITIONAL INFORMATION

For additional information, see the Waters AccellPlus QMA and CM Bulk Media Care and Use Manual.