Can I use the freezer to separate the nps from the water layer like i would when doing cactus extractions or will I have problems with DMT precipating out and sticking to the frozen water. I would assume if i dont leave in the freezer too long it should be o.k.

I don't know for sure, but my guess would be that DMT will precipitate before the aqueous layer freezes. So the DMT would precipitate out of the NPS, leaving it suspended in the aqueous layer as it freezes, instead of dissolved in your NPS.

thanks for your reply enth'. I might try it anyway as I have today discovered my sep funnel needs some repairs. I think i will use more nps than usual and hope the good stuff remains in solution

If the NPS is dilute (very little DMT per ml of NPS), then the DMT won't precipitate. So if you were to use excess NPS it might work, you would just have to evaporate a good bit of the volume off after you separate the layers in order to proceed with freze-precipitation.

So this did work but i didnt get the yeilds i expected

This could be partly from DMT precipitating out of your NPS, when freezing in order to separate the layers. Try doing a few more heated pulls without using your freezer method.

yeah thats what ill do i just have to replace the tap on my sep funnel first as its no longer turning off.