I'm doing set up Shimadzu GC 2010(FID*1) to measure biomass derives catalytic conversion. So, I need to measure glycols, alcohols, sugar alcohols and some other organic acids and so on.
I have referenced some articles Green chem., 2011, 13, 91-101. I've equipped Rtx-VMS then I injected 1uL by auto injection of 10wt% Sorbitol with split ratio of 200.
when its ratio of 200, it doesn't found any specific peaks, however when I inject with split-less mode or 1~20 ratio, It found like thermal decomposition.
However, I've tried around 100 ppm of sorbitol (1uL injection), ratio of ~20, it doesn't found any specific decomposition.
Have you ever happen this kinds of thermal decomposition during GC analysis?
How can I set up GC? Can you give me some advice?
No such experience. Theoretically too high injector temperature may cause thermal decomposition. Have you used temperature over the decomposition point or autoignition temperature?
Two possibilities, I think, and they are complementary. First, there is thermal decomposition, but not relevant and you are only able to see it when you introduce more into your column, e.g., when your split is lower. Second, with lower split, it takes more time to introduce your sample into the column and then the higher temperatures in your inlet are more effective to produce thermal decomposition and so you are able to observe it.
You are splitting away your analyte. Set your split ratio to between 10 and 20 - make sure you calculate it correctly!!!