Dear forummembers,

I don't know if this is the right place for my question, but I hope someone can give me some advice.

For blood and urine samples, we use a manual SPE procedure (Vac Elut SPS 24 at 5 to 10 inHg) with plastic valves to regulate the flow rate. Lately we have noticed some carry over of cocaine. Apparently, the cocaine stays stuck on the plastic valves of the SPE system.

Has anybody a good cleaning protocol for the SPE system (and especially the plastic valves) to avoid this?

Thanks!