different retention time though the methods are the same

[Bill040689]

Dear users,

I am seeking an answer of a strange phenomenon in my GC-MS results. I conducted an objective analysis using GC-MS towards a certain papaya variety extract to see the volatile patterns. The result showed that naphthalene occured at 30.45 minute. I conducted another test using the same method and column but different papaya variety. The result was naphthalene occured at different retention time: 37.12. What had happened?

[Peter Apps]

One or both of the peaks that the MS search says is naphthalene, is not naphthalene Or a system fault, or operator error.

Peter

[Bill040689]

Thank you, Mr. Peter. =]

[Fee]

Look for the match with the library ; is it higher for one of the compounds ?

Which software are you using ? ChromaTOF is known to find a lots of "false positives".

You really need to compare with standards to confirm compounds retention time.

Hope that helps,

Fée