By Jimmy on Wednesday, February 18, 2004 - 10:44 am:
During HPLC Method Development for guanosine, strange stability data were seen here. It was dissolved in water at 50ng/mL. For comparison purpose, it was stored in plastic vials, in vials with deactivated glass inserts or in vials with regular glass inserts. When stored in room temperature outside of autosamplers (wrapped with aluminium folie), they appeared very stable (less than 10% less); however, when stored at room temperature inside the autosampler, they dissappeared overnight. Apparently the instability has nothing to do with vials. What caused the stability problem? The magnetic field inside the autosampler? I am really puzzled.
Please help me out. I am an analytical chemist and don't remember much organic chemistry.
Thanks in advance.
Jimmy
By Anonymous on Wednesday, February 18, 2004 - 11:09 am:
How warm is your autosampler storage area? 22°C? 28°C ? 33°C ?
By Jimmy on Wednesday, February 18, 2004 - 11:23 am:
Our room temperature is 19-22C. Temperature inside autosampler is 25-26C around lunch time. The temperature difference is very small. Would it cause such a different stability?
At night both temperature would be lower.
BTW, the cpd is stable at 4c for very long time in glass tubes.
By Anonymous on Thursday, February 19, 2004 - 07:20 am:
WELL, do the experiment for stability at 25°C to determine if it is temp related. That's a start.