We are intersted in testing the presence of diethyleneglycol in wines. We have a glass column (6' x 4 mm)filled with 5% diethylene dlycol succinate + 1% Phosphoric acid on chrom W-HP 80/100. Isothermal conditions at 200 C. FID detector.
We are injected an aqueous solution of 10% ethanol and 10% diethyleneglycol. The problem is bad resolution for less than 10%, and not "pure" peaks.
The sample will be wine as is, with and without the adding of a drop of diethyleneglycol.

We haven't analyzed wines, but we've had real good results for diethylene glycol using capillary GC after trimethylsilyl derivatization. Take 0.25 g wine to 10.0 ml with DMF. Mix 500 ul with 250 ul BSTFA, capillary GC split injection on nonpolar column such as HP-1 or HP-5, or on packed column with similar phase. This is an easy one.