What is Waters Magic Mix/AAA Wash? - WKB238676

ENVIRONMENT

• Alliance HPLC Systems
• ACQUITY Arc Systems
• ACQUITY UPLC Systems
• ACQUITY UPLC H-Class
• ACQUITY UPLC I-Class
• ACQUITY UPLC M-Class
• nanoACQUITY UPLC

ANSWER

Waters Magic Mix (also known as AAA Wash) is a general cleaning solution used to remove contaminants from internal HPLC and UPLC system components. It typically consists of equal parts (25:25:25:25) MS- or HPLC-grade water, acetonitrile, methanol, and isopropanol, with 0.1–2% formic acid added.

ADDITIONAL INFORMATION

General Cleaning Procedure:  

1. Remove the column and replace it with a union.

• This protects the column from damage during cleaning and allows full flushing of the system.

2. Remove solvent sinkers from all solvent lines.

• Their large surface area traps contaminants and they’re slow to flush clean. Removing them during cleaning also prevents damage from harsh solvents.

3. Place all solvent lines (from the ACQUITY/Alliance) into a cleaning solution.

• Use Waters Magic Mix (as above) with an appropriate formic concentration (0.1–2% depending on levels of contamination)

4. Flush the system:

• Prime each line with the cleaning solution for ~5 minutes to ensure it has replaced the previous solvent.
• Pump the cleaning solution through the system for at least 2 hours continuously.
• For heavily contaminated systems, extend the cleaning overnight or even over several days if needed, using a low flow rate to maximize wash contact time.
• Use a restrictor or back-pressure device to maintain appropriate back pressure during cleaning.

5. Flush with water:

• After cleaning, prime and flush the system thoroughly with fresh LC/MS-grade or Milli-Q water to remove residual cleaning solution and acid.

6. Refit solvent sinkers.

• Before refitting, inspect and, if necessary, clean the sinkers to avoid reintroducing contamination.
• Note: New sinkers may carry residual contamination, which can cause application-specific suppression until they are thoroughly flushed.

7. Replace with fresh solvents:

• Place all solvent lines into freshly prepared, LCMS-grade solvents intended for analysis.
• If solvent bottles have not been cleaned recently, rinse them with the alcohol cleaning solution, then rinse thoroughly with the intended fresh solvent.
• Prime all lines again (including flushing through the union) to fully replace the cleaning solution and water.

8. Refit the column:

• Once the system is fully flushed and equilibrated with the analytical solvents, reinstall the column and allow it to equilibrate before running samples.

 

If the contamination persists, refer to Controlling Contamination in UPLC/MS and HPLC/MS Systems Guide (715001307)