I have been running FAMEs on our GC-c-IRMS using a 30m DB-5 column with 5m of guard column. The first six samples returned good peak resolution. After the sixth, I now get very poor resolution. Instead of well-defined peaks at the expected retention times, I'm getting hundreds of peaks at low amplitude (<100mV) throughout the run.
The GC method I'm currently using is as follows:
90-280C, 3C/min., 20 min hold; Flow rate 1.2 ml/min. He; Injection: splitless w/ surge.
Can anyone tell me what's happened, and how it might be fixed?
Melissa D. Bautista
IRMS Research Technician
Centre for Coastal Biogeochemistry
Southern Cross University
P.O. Box 157 Military Road
Lismore NSW 2480
Phone (02) 66 269 565
Mobile 0431928278