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- Posts: 2
- Joined: Mon Oct 01, 2018 2:52 pm
I need some help understanding the theoretical plates calculation of merck columns, when I got the column it cames with a certificate thats saids
minimun theoretical plates 80000 the certificate saids it haves 101569 under these conditiones
Acetonitrile/water (75/25 v/v)
1.3 ml/min
1 ul injection volume
UV 254 nm
Detector cell volumen: 3.2 uL
Extra-column volume: 25 uL
I made my theoretical plate determination and I got 16500 under these conditions
Acetonitrile/water (75/25 v/v)
1.3 ml/min
1 ul injection volume
UV 254 nm
Detector cell volumen: 13 uL
I returned the column for test and some time later I ask merck to solve the issue they gave to me a the test made to the column they got 62000 theoretical plates under these conditions
Acetonitrile/water (75/25 v/v)
1.3 ml/min
10 ul injection volume
UV 254 nm
Detector cell volumen: 13 uL
The injection volume is highly incresed, I ask for an explanation but the only thing they told me is that I will never get the theoretical plates from factory because of the detector cell volume.
It´s possible that the detector cell volumen is so critical in the determination that i am getting way less than they get on factory or they are trying to just to gave explanations to don´t accept my column is bad?