A Better Drying Pistol We wish t o report a modification of the conventional drying pistol that we find t o be an excellent improvement. Our modification consists of constructing the drying pistol with a removable drying chamber, Figure 1, containing a male $45150 ground glass joint for connection to the outer vapor chamber. Our specific drying apparatus, Figure 2, was patterned after the Abderhalden drying apparatus (Ace Glass) and constructed by R. W. Moshier and R. Strohschein (University of Florida Glass Shop). The drying chamber is 25.5 cm long by 25.4 mm i.d., with a El4140 male joint for attachment to the desiccant flask. The desiccant flask also contains a 2-mm HV stopcock for tube connection to a vacuum. The outer vapor chamber is 25 cm long with $24140 joints for connection to the boiling flask and condenser and a female $45150 joint for insertion of the drying tuhe.
Figure
I . Removable drying c h a m b e r
and d e s i c c a n t f l a s k .
F i g u r e 2. Modified drying p i s t o l .
Vapors from the boiling liquid contained in the flask heat the outer wall of the drying chamber. The vapors ascend to the condenser, condense, and fluw down a separate tube to the boiliug flask. With this modified pistol, the saniple can be sealed in the drying chamber, and then the entile chamber removed, cleaned on the outside, weighed. and rsplaced fur furthir drying to achieve an accurate constant weight without sample transfer; the utilization of the male joint on the drj-ing tuhe coauevtion allows for the facile removal of tho stopcock giease for mass determination. Oxice dly, the staled iha.nbc. can be easily transferred t o a d r y box for sainple removal u.ider inert atmosphere. By use of a number of drying chambers, several samples can be dried in series without dismantling and cleaning the main chamber, flask, and condenser assembly, allowing for more efficient use of the apparatus. Besides these advantages, this design is an inexpensive and effective method of servicing multiple users. The is more easilv cleaned. esoeciallv when use of an alcoholic ~otassiumhvdroxide bath is desired. removable drvineehamber , ,. And a i t h our m d i f ~ m t l m each , user mainrains and urrs his or her o w n d r y n g r h n m h w mdrlrtndently of the vapor chamlrer, flask. and condenser aasemblp. which we maintain in a fired cenrral lurnticm. K. 6. Wagener and J. C. Matayabas, Jr. University of Florida Gainesville. FL 32611
Volume 65
Number 6
June 1988
557
