A Versatile Micro-Distillation Apparatus
7-
Distillation of liquids an a microscale, particularly those which are volatile, is always a cumbersome process. The most common apparatus for this purpose is the Kugelrahr,' which though it is said to be exceedingly useful for the purpose, is not without shortcomings. First, cooling of the receiving bulb(s) by a swab of cotton-wool soaked in methanol or by a piece of dry ice held over the bulbs is rather inefficient. Second, after the distillation is over there is always a problem in transferring the distillate into an ampoule or other container. We have circumvented both these problems by a slight modification of the kugelrahr apparatus as shown in the figure. The advantages of this modification are: 1) Even highly volatile liquids can be safely distilled without fear of loss (by immersing the ampoule in liquid Nz), and 2) The liquid can be directly distilled into an ampoule, thus avoiding the transfer from a bulb to an ampoule. The apparatus can be very conveniently fabricated by any glassblower and if the situation demands, i t can be used repeatedly by attaching a new ampoule after distillation.
' Lowenthal, H. J. E., "Guide for the Perplexed Organic Experimentalist," Heyden, Philadelphia, 1978, p. 102. R. C. Desai Clemson University Clemson. SC 29631
K. M. Saplay Hindustan Lever Research Center Bombay. India
524
Journal o f Chemical Education
