What is the optimized cleaning procedure for difluoroacetic acid (DFA)? - WKB109893

ENVIRONMENT

• Mobile-phase additives
• IonHance difluoroacetic acid (DFA)
• LC
• LC-MS
• Solvents

ANSWER

Optimized cleaning protocol for DFA

Prime solution: 5% FA in 25:25:25:25 water/MeCN/MeOH/IPA

Wash solution: 2% FA in 25:25:25:25 water/MeCN/MeOH/IPA

1. Remove sinkers from lines and switch to 5% prime solution using an “air gap” + “inbetween” solvent changing technique (original MP > air gap > inbetween vessel > air gap > wash solution). Be sure to wipe away any residual DFA solution before submerging into the 5% prime solution.

2. Prime all lines in contact with DFA for 20 minutes with 5% prime solution.

3. After priming, switch to 2% wash solution using an “air gap” + “inbetween” solvent changing technique; be sure to wipe away any residual 5% prime solution before submerging into 2% wash solution.

4. Run 2% wash solution at 0.5 mL/min for a minimum of 1 hour to waste. Do not run high % FA through %S detector.

5. Run series of intact mAb on Bioresolve RP column to check for signal intensity and adduct levels. Check for continuously increasing signal intensity.

ADDITIONAL INFORMATION