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- Posts: 4
- Joined: Fri Nov 22, 2019 1:15 pm
I have some questions about my method for testing acetonitrile in an aqueous sample. I use a GC-FID
First my GC settings (GC 6890N):
inlet temperature: 200 °C
Detector temperature: 250 °C
Splitless injection: 1 microliter was injected with autosampler
Temperature program:
0-3 min: 60°C
after that it rise with 80°C/min to 220 °C then it holds that temperature for 2min.
Hydrogen and nitrogen: 40 mL/min
Air: 400 mL/min
Column: HP FFAP 30 m * 320 μm * 0.25 μm
1) I don't get consistent results. I've read that it's hard to get good results with a GC-FID for testing acetonitrile. But it's not impossible I hope? Because I don't really have an alternative. I found another method with GC-NPD but the upper range of this method is 5 mg/L and my range of concentration lies between 5 mg/L and 250 mg/L so that's also not an option.
2) maybe my column is broken. On the picture you see that at the end there're a lot of peaks and the baseline gets higher. I searched this and maybe this is columnbleed? Can I fix this or will the results be better with a new column?
Thanks in advance