By Anonymous on Wednesday, December 17, 2003 - 01:53 am:
I am using a Zorbax Bonus-RP 4.6mm id x 100mm x 3.5um. I am running 1.2ml/min of 0.1%TFA in water and acetonitrile (70/30).
Assuming no effect on resolution can anyone tell me a approx. maximum injection volume?
The injection solvent can be distilled water or 0.1% TFA in water.
Thanks for your comments
By RH on Wednesday, December 17, 2003 - 06:39 am:
For analytical purposes keep it below 1% of Your column volume.
By A.Mouse on Wednesday, December 17, 2003 - 09:48 am:
Since you are injecting in water and enriching the sample on top of the column, you may be able to inject as much as a milliliter of sample.
By Tom Mizukami on Wednesday, December 17, 2003 - 09:49 am:
Since you are injecting a weaker solvent than the mobile phase you may be able to take advantage on on column concentration. For dissolution testing of highly potent compounds we have injected 150uL or more with a similar setup.
In general I would stick with the advice of RH, or about 10ul for your column.
By Vojtech on Thursday, December 18, 2003 - 01:09 am:
I use columns 3,9x150 mm and I inject 50 ul of sample (in water). I see no difference between 5 ul and 50 ul. I work with acetonitrile gradients (10-80%).
By Uwe Neue on Thursday, December 18, 2003 - 10:28 am:
I recommend to inject the sample in 0.1% TFA in water. With this injection solvent, you can use a fairly large injection volume, since it is more polar than the mobile phase. I do not knwo how far you can go, but I would guess that a few hundred microliter should be possible. Your retention time will increase slightly due to the volume injected.