Chromatography Forum

Can anyone tell me where do i find the standard peak?
Due to i just run GC by using the plastic bags sample which have the smell.
So, the result has so many peaks that I can not identify the substances which have smell.
Please help me.
Best Regards,
Austinboy
P.S. If anybody want to see the result, i will sent you the email.

Hi

Am I right that you are trying to identify the compound(s) that cause a smell in plastic bags ?

There are a number of things that you can try.

Run a chromatogram from a smelly bag and a chromatogram from a bag of the same sort that does not have the smell. Look for peaks that are present on the chromatogram from the smelly bag and absent form the good bag. These are quite likely to be associated with the odour.

Do GC-sniffing; split the effluent from the column between the detector (in this case it is best to use an FID) and a sniifer port. Smell at the sniffer port, when you smell the off-odour note the time, the peak(s) that elute at that time are probably due to the off-odour. You can also do one run with the detector on to get a chromatogram, then do another with the column removed from the detector while you sniff at the end. Match the retention times of the odour with the retention times of the peaks.

The nature of the odour and the identity of peaks can also guide you. If you have a smell like rancid fat it is probably an aldehyde, disinfectant might be a phenol, plastic might be styrene etc etc.

Good luck

Peter

Hi,

Peter has covered off everything (especially about the reference) but I would just ask

1. describe the odour - is it a malodour?
2. is this a one off problem or bag odour in general?
3. is there any printing on the bag? I have analysed some supermarket carrier bags recently with a malodour problem. It was due to the printing ink used.



Ralph