Ethylene Glycol in Polysorbate 20

[rextc169]

Trying to develop a GC method for determining ethylene glycol in Polysorbate 20. Any suggestions would would greatly appreciated. If you have ever worked with Polysorbate 20, you know what a pain that yellow viscous goo can be. Direct inject is gunking up the detector and trying to find a solvent for headspace has been a problem.

Thanx

[Consumer Products Guy]

Use DMF as solvent, maybe 2 - 5% sample in the DMF, filter if necessary. Mix filtrate 1:1 with BSTFA derivatizing agent. Inject (split injection) on non-polar DB-1 or DB-5 type capillary, start at low temperature like 80C, hold there a few minutes, then ramp up if desired. You need to make a reagent blank of DMF and BSTFA because the EG will elute JUST AFTER the BSTFA excess.