Chromatography Forum

I would like to make the purchase of a new High Temperature GPC system.
I am hesitating whether to buy Viscotek HT-GPC 350 or PL-GPC 220.
Can anybody compare these instruments?

Yaakov,

We probably could if we had a little more information,
SEC instrument these days have several configurations depending on the user applications.
what is the Mw range you will need it for?
Do you check for copolymers?
what characteristics of your polymers do you want to check, measure QC?
do you need Rh, Rg?
do you need to check for branching?
agregation? at what level of detection? it is over time as well?

what are the system configurations that you are evaluating?

knowing these would help

unmqvar,


Mw 1,000-1,000,000
I do check copolymers
I need Mn, Mw, Rh, Rg no QC
I do not need to check for branching?
I think about RID-Visc-LALS-RALS

Thank you

yaakov,

if i remember well if you are looking for copolymers, you will need normally a second detector like UV in there.
see how it is connected to the machine. see how the noise is handled.

going to the 1000000da requires to have as low an angle you can in the LS system and 2 or more angles are better then one. normally the 7 angle of viscotek is the best you can get right now.

yes having a visc detector in there is i think important, I prefer this approach to those that want to add more then 2 angles in the LS.
check the Visc about how it handles the huge range you want to go for.
there is a delay column in there and normally there are 2 sizes, each size is best for a certain range. normally for a range like yours you will need the bigger delay and this means you will have a little less accuracy for the smaller Mws.
if you do want to split the ranges some time see how easy it is to swap/add or remove these columns in each module.
from my experience in the viscotek machines it is taken into account

unmgvar!
Thanks a lot.
Yaakov