Propylene Glycol in water

[WK]

Dear All,
Does anyone know a good way to analyse propylene glycol in water at the 0-100ppm range?
Does it involve SPE before GC analysis?
In tried a C18 cartridge with hexane to elute but I guess PG is so polar it does not stick.
I have tried SPME and headspace at 80degC with obviously no luck!
Thanks in advance for any replies,
WK

[BG]

Hello WK

did you try first with Split/FID (without sample preparation before as spe or spme)?

With very low split ratio and a wax 57 CB as column (for example); in range of 10 to 250 ppm it could working!

[WK]

Thanks BG,
I didn't try since the water contains caustic and I didn't want water on the column.
I will try liquid liquid extraction today into hexane but I don't hold out hope!
WK

[chromatographer1]

You will have found out my now that extracting PG is not an effective means of isolation.

I would suggest that you use a precolumn of Supelcowax type capillary, perhaps only 1-5 meters in length and replace it when the peak degrades.

You could try concentrating the PG by distillation and then redissolving the PG into IPA to remove most of the salts involved.

Interesting problem. good luck.