RDA low response detected during instrument setup after making fresh lockmass - WKB70324

SYMPTOMS

• Instrument setup fails
• Error: Low response detected

ENVIRONMENT

• BioAccord System
• ACQUITY RDa Detector

CAUSE

Not enough signal strength from leucine enkephalin lockmass solution

FIX or WORKAROUND

1. Make a fresh bottle of lockmass solution.
2. Shake the bottle well for at least 30 seconds.

ADDITIONAL INFORMATION

There are two LockMass solutions availble to order from waters.com. The part number 186009298 is for BioAccords using waters_connect software and 186009012 for UNIFI

Be certain to gently tap the sealed full vial of the stock solution on the counter before breaking off the top neck, to ensure that all the solution is out of the sealed neck area.

Be very careful when snapping the neck off of the vial.  

When dumping the vial with the leucine enkephalin stock solution into the mobile phase diluent, you need to very quickly and gently tap open end of the vial into the top opening of the diluent bottle. Getting all 5 milliliters out of the stock bottle may take up to two minutes of this tapping motion.