Two columns in series??
Posted: Sat Apr 09, 2022 5:28 pm
Hello there!
I have received a shiny new Agilent 7000D (Agilent 8890 GC with 7000D MSD) which I am in the process of getting to grips with. I was expecting it to be delivered with a 30m HP5ms column, but instead, it was delivered set up with a 15m HP5ms type column which is joined through some kind of union (itself connected to gas supply perhaps via a secondary EPC?) to a second 15m HP5ms column which then joins into the MSD as normal.
This isn’t exactly a setup with which I am familiar and I would be much obliged for some advice as to whether this setup can provide equivalence to a single 30m column and if so how I can achieve this? Is it as simple as setting the flow rates for both columns to the same value (i.e. 1.4ml/min) or is it more complicated?
Beyond the ability to do concurrent backflush (and all that fancy stuff) are there any additional benefits of this kind of setup? I’m guessing that the first column probably takes the brunt of any fouling etc. so perhaps it might allow changing of just column 1 when the inevitable happens and resolution is lost (and I guess a 15m column is cheaper than 30m) or is that wishful thinking!?
Many Thanks
Richard
I have received a shiny new Agilent 7000D (Agilent 8890 GC with 7000D MSD) which I am in the process of getting to grips with. I was expecting it to be delivered with a 30m HP5ms column, but instead, it was delivered set up with a 15m HP5ms type column which is joined through some kind of union (itself connected to gas supply perhaps via a secondary EPC?) to a second 15m HP5ms column which then joins into the MSD as normal.
This isn’t exactly a setup with which I am familiar and I would be much obliged for some advice as to whether this setup can provide equivalence to a single 30m column and if so how I can achieve this? Is it as simple as setting the flow rates for both columns to the same value (i.e. 1.4ml/min) or is it more complicated?
Beyond the ability to do concurrent backflush (and all that fancy stuff) are there any additional benefits of this kind of setup? I’m guessing that the first column probably takes the brunt of any fouling etc. so perhaps it might allow changing of just column 1 when the inevitable happens and resolution is lost (and I guess a 15m column is cheaper than 30m) or is that wishful thinking!?
Many Thanks
Richard
