Chromatography Forum

Hi,

New here. I'm running HPLC-UV in a Gemini C18 150x2mm, 5um at 70:30 ammonium formate buffer:MeOH at 50C, FR 0.3 mL/min. I'm running stock solution isocratic, but recently there has been a huge sudden jump in my baseline when it used to just be flat. The first time it happened was at 4 minutes, and now it's happening around 13 min. The chromatography baseline actually looks flat when read at lower wavelengths. Any suggestions?


Above read at 319 nm.


Above read at 244 nm.

Are there any events programed in the detector?
It looks like the baseline has been reset.

Are there any events programed in the detector?
It looks like the baseline has been reset.

Ah I may have posted prematurely as we ran the same program a few more times and the baseline returned to normal. Strange, I also figured it was something with the detector since it’s was such a sudden jump. Our machine is very old.

Your baseline seems noisy , so the deuterium lamp of the detector may be end of its life.

The baseline jump may also be related this.

Your baseline seems noisy , so the deuterium lamp of the detector may be end of its life.

The baseline jump may also be related this.

Ah, ok. We ordered a new bulb last week, hopefully that’ll fix it, because after running over the weekend, the jumps have gotten more frequent.

Thank you!