Based on our conversation, I decided to pull an old aspirator pump out of storage to use as the vacuum source for a fraction from a different synthesis, that eluted with hydrochloric acid. When I used to use this more regularly, I used a slow feed of water from a tap to replace the water in the pump. If one left this out, the water would gradually get warmer. However, my present laboratory layout does not allow for such a set-up, and simply putting ice into the water reservoir of the pump means that ice is drawn into the jets. Therefore, I filled a nylon fine washables bag with ice and put the bag into the water. It seemed to work well. I then add two portions of water to the sample to remove residual acid from the sample.