Chromatography Forum

Hi all,
I have to develop the method using Evaporation Light Scattering (PL-ELS 2100 detector). I want to use DMF instead of THF, wonder if it is possible? if i increase the evaporation temperature or if you have any suggestion, please let me know.

thanks

Hi all,
I have to develop the method using Evaporation Light Scattering (PL-ELS 2100 detector). I want to use DMF instead of THF, wonder if it is possible?

Yes. You likely will need to raise the nebulizer temperature.

Why do you want to use DMF? Any particular reason, like selectivity, solubility or else? I can't imagine a reason why you want to do this.

Hi all,
I have to develop the method using Evaporation Light Scattering (PL-ELS 2100 detector). I want to use DMF instead of THF, wonder if it is possible? if i increase the evaporation temperature or if you have any suggestion, please let me know.

thanks

As I know the evaporation temperature is depends on the sample

thanks for the tips with ELSD, really appreciate it

I used DMF for PMMA and polyurethane samples using Wyatt Instrument (Refractive Index) for another company, now i am working for different company and they have ELSD GPC Instrument.

I dissolved the samples and PMMA in DMF and it shows peaks, Now i am trying to adjust the Nebulizer temperature and evaporative temperature to get resolved and smooth peak.

Agilent recommended to use Ammonium acetate or Ammonium formate (0.1%) in DMFmobile phase. I will try to increase the Nebulizer temperature and will see.

Yes, Vlad Orlovsky I want to use DMF, because of the good solubility of most of the samples. Which solvent would you recommend for ELSD GPC.
Please let me know
Best Regards

from my experience a lot of compounds dissolve in EtOH/THF mixture. My guess is that with DMF you will need to set up temperature of ELSD around 100*C. Make sure that your compounds are not evaporating at this temperature becuase you will see poor linearity at lower concentrations.

Thanks Vlad for your suggestion:)
what ratio would you recommend for this THF:EtOH mixture (90% THF:10% EtOH) or what? Please let me know
when you have time.
I really appreciate it.
thanks so much
Best Regards