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- Posts: 1
- Joined: Wed Sep 25, 2013 9:38 am
In our Qc system we use a Waters UPLC system with column manager and a berthold radioactivity detector after the UV detector
Lately we had some very odd results with a compound:
I did the run on two completely the same systems with the same column:
PROBLEM: There was an activity peak about 10% of the sum visible at 0.3min on one system but not on the other system. I repeated this run three times, same result every time.
My next thought was that it was not passing the column but went immediately through the uv detector (and radioactivity detector) because of a leakage at some valve, but when I put the column immidiately after the injection( so bypassing the column manager valve) the problem still exists.
Afterwards I put in a another column and the problem still exists
Strange things is I use the same eluent bottles for both systems, aswell as the same seal/needle wash bottle for both system
For this compound we are using the following system
UPLC Column :ACQUITY UPLC® BEH C18 1.7µm; (2.1mm x 50mm)
Mobile phase Water (0.1% TFA) /Acetonitrile (0.1% TFA) gradient (start with 10% ACN at the start to 50% ACN in 6 minutes)
Radioactiviteit Berthold Flowstar LB 513
Flow 0.8ml/min
UV detector:280nm
column temp. 35°C
Injection volume: 10 µl
System Pressure around 10000 PSI
Analyzing a small molecule with a molecular weight of 318
Lately we had some very odd results with a compound:
I did the run on two completely the same systems with the same column:
PROBLEM: There was an activity peak about 10% of the sum visible at 0.3min on one system but not on the other system. I repeated this run three times, same result every time.
My next thought was that it was not passing the column but went immediately through the uv detector (and radioactivity detector) because of a leakage at some valve, but when I put the column immidiately after the injection( so bypassing the column manager valve) the problem still exists.
Afterwards I put in a another column and the problem still exists
Strange things is I use the same eluent bottles for both systems, aswell as the same seal/needle wash bottle for both system
For this compound we are using the following system
UPLC Column :ACQUITY UPLC® BEH C18 1.7µm; (2.1mm x 50mm)
Mobile phase Water (0.1% TFA) /Acetonitrile (0.1% TFA) gradient (start with 10% ACN at the start to 50% ACN in 6 minutes)
Radioactiviteit Berthold Flowstar LB 513
Flow 0.8ml/min
UV detector:280nm
column temp. 35°C
Injection volume: 10 µl
System Pressure around 10000 PSI
Analyzing a small molecule with a molecular weight of 318
