Chromatography Forum

Hi Folks,

The method below has produced constant overpressure after 8h to 14h of pump flow (analysis). The pressure starts with 170 kgf/cm2 but always the chromatograph stop before the end of the analysis,since the max. pressure is 400 kgf/cm2.

1) Do you have any ideia about the cause?

2) Is it common any THF generate column pore swelling?

Chromatographic method
Mobile phase composition: MeOH = 90%, THF = 5%, Water = ¨5%
Flow rate: 1.5 mL/min
Temperature: 25 degree Celsius
Column: C-18 Zorbax 250mm 4.6mm 5um

Thanks,

We've used THF for years with RP-18 columns, and not had any such issues. If you haven't already, run the sequence but WITHOUT actual injections for your 8 to 14 hour timeframe, and see if the pressure still goes up like you stated. And post what you find.

Sorry for my delay... we just changed THF for ACN and problem was resolved.

Wonderful elutions for everybody!!