Chromatography Forum

Headspace - I am new to headspace testing and I am tryng to develop a method for MHE as a means for quantifying sesamol in plastic film. In theory each subsequent injection should yield a smaller peak area, which is necessary to establish a regression and get slope and so forth to plug in to formulas to get amount in vial etc. If r value is poor - that would indicate the sample is not reaching equilibrium (btwn matrix and headspace or gas phase). My problem is I am getting identical peak area for each injection. What does this scenario mean??? I know sesamol is vary volatile - how do I change my method to get MHE to work with sesamol?

Most likely your sample is too big and the headspace is becoming saturated before an equilibrium is reached.

Every time you reach what you think is equilibrium it is actually only a saturated system. Continued extractions continue to reach saturation of the system so your peak size remains constant.

I would try reducing the size of your sample.

best wishes,

Rod