Hello there,
some days ago, when I was performing an analysis on an Agilent GC 8890 system coupled to a 5977B GC/MSD, with a robotic PAL RSI 120 autosampler, I observed that in all my samples, including the previous blank, appeared an intense signal which corresponds to Benzenemethanol, α , α -dimethyl- (score around 900, so it is a good match factor). The blank was ran first, so I discarded the samples to be contaminated with this impurity. Then, a few days later, I ran a blank, but with the complete adquisition mode (incubation, inyection with the HeadSpace tool, etc), and the compound was still there. So, I thought it could be because of my column. To eliminate it, I calculated the temperature at which the GC was in the retention time the coumpound eluted, and it was 190 ºC. So, I programmed the oven at a high temperatue during some minutes to try to eliminate it from the column. It does not disspaer, and the signal has the same intensity in different blanks I have done. i don't know where can it came from, but it is from the column, because I also ran just a GC blank, without the PAL autosampler injecting, and the impurity also appears.
I attach two photos: one where the blank corresponds only to the chromatographic process and one of the blank where the PAL autosampler injects. In both images, the compound appears with the same intensity and good match factor.
Thanks in advance, regards.
