A Homemade Blowdown System for GC Vials

Our Turbovap is an excellent tool for drying down solvent in large VOA vials, but it does not work well with other sizes of vials. We needed something that could dry samples in GC vials, so Alex designed this smaller blowdown system. At the base, the black box contains a pressure gauge as well as switches to control the nitrogen flow to each pair of tubes. Above this, there is space for a small dry bath so that samples can be heated to speed drying. At the top, the white plastic block holds and guides the stainless steel nozzles (made from 1/16" capillary tubing) that are affixed onto the plastic nitogen delivery tubes. The block can slide up and down on the metal posts at either side of the dry bath, allowing the system to accomodate vials of different heights. Teflon tubing connects the switches in the black box to the nitogen delivery tubes. The biggest drawback of this system is that the nozzles are difficult to keep accurately aimed into small vials, as the tubing tends to twist just slightly. Passing the steel nozzles through holes in a stretched rubber band greatly diminishes this problem.