weak peak or no peak

[drbraikeet]

Hi everybody
When i inject my sample ( i look for melamine ) using GC-MSD 5973 no peak will appear while in the same time the internal standard peak is very beautiful and high, i am sure my sample is positive and contain melamine.
There is something missing but i do not know what is it?
Can i get help please

[chromatographer1]

Have you considered the possible reaction of an amine with bare metal in your MSD?

with the fused silica surface of your capillary column?

with the glass in your injection port?

with itself at high temperatures in the injection port?

with the other components of your matrix?

with the metal in the syringe needle?

Oh, the possible chemical reactions, let me count the ways !

Remember, if it were easy, anybody could do it.

best wishes,

Rod

[HW Mueller]

One normally does this with standard substances before running unknown samples. Chromatography methods need to be calibrated.

[Don_Hilton]

The question of what else is in your sample and how you are extracting the analytes is quite important. For example, if there is cyanuric acid also present, you may have a very difficult time extracting and analyzing melamine.

[drbraikeet]

Thank you guys for the respond