I read that Fresh THF without preservatives is generally clean of peroxides, Once opened, and the THF is exposed to oxygen then peroxides start forming immediately, unless you exhaustively purge out the air. Butylated hydroxytoluene (BHT) is added in some THF as preservative to stabilize the THF. My question is what makes this peroxide formation result in background signal in GPC?. The last GPC Analysis we did in our lab was done with the inhibitor free THF and there were a lot of background signals we couldn't get a clear result