Quantification of caprylyl glycol (1,2-octanediol) by GC/FID

Hi,

You want to add an internal standard (ISTD) to your sample before any work-up.

Your ISTD needs to be structurally similar to your analyte but still different enough not to elute at the same RT. (if you were using GC-MS, you could use deuterated caprylyl glycol). That way, any changes (loss of sample, problem during injection, adsorption of analyte by filter,...) to your sample will happen as well to the ISTD and this can be corrected.

Your calibration solutions will need to have the same amount of ISTD you added to your sample. 

Now, if you can come up with a quantifying method for HS/GC-FID, it would be much easier as there is virtually no sample preparation.

Hi,

You want to add an internal standard (ISTD) to your sample before any work-up.

Your ISTD needs to be structurally similar to your analyte but still different enough not to elute at the same RT. (if you were using GC-MS, you could use deuterated caprylyl glycol). That way, any changes (loss of sample, problem during injection, adsorption of analyte by filter,...) to your sample will happen as well to the ISTD and this can be corrected.

Your calibration solutions will need to have the same amount of ISTD you added to your sample. 

Now, if you can come up with a quantifying method for HS/GC-FID, it would be much easier as there is virtually no sample preparation.

Hi, 

Thank you for your answer. 

I tried with headspace but my calibrations are made in water and my sample is an emulsion. So the caprylyl glycol isn't in the same quantity in the headspace.

I have decades of experience with consumer products, all on Agilent GC, GCMS, and HPLC.

If I was needing to quantitate 1,2-octanediol in cosmetics samples, I'd extract the sample with dimethylformamide and add BSTFA to make trimethylsilyl derivative, and assay by GC-FID on a HP-1 or HP-5 type column. 

We assayed numerous glycols in this manner.