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- Posts: 13
- Joined: Fri Nov 03, 2017 2:47 pm
Parameters:
-Gradient runs using HPLC grade Water, Acetonitrile and MeOH.
-use a Zorbax C18 column and guard column.
- runs are 40 minutes long
-detector is fixed at 360 nm
The instrument ran for 3 months with no problems. Currently, our retention times have shifted. The beginning compounds shift to the left and the remaining 2/3's of the compounds shift to the left and then to the right. Some have shifted by as much as a minute.
Pressure and delta are normal.
We have changed:
guard column and guard column assembly
check valves - done by waters technician
seal pack - done by waters technician
analytical column
sinker frits for all solvents
in line filter
Any ideas or suggestions are welcome!!!