On-line monitoring of vacuum dryers using mass spectrometry

Mass spectrometry was used to monitor vacuum-drying endpoints in the laboratory and pilot plant to demonstrate feasibility of its application. The technique is relatively simple to interface to existing equipment at minimal cost, requires no direct sample contact, and is generally applicable to multiple dryer configurations. Results of the feasibility study showing the monitoring of multiple solvents, along with correlation of the mass spectrometric technique to conventional percent loss on drying (LOD) measurements, are discussed.