applied t o a n y material t h a t can be separated b y paper chromatography or by other micro separation techniques and should find wide application in biological studies. RI values from paper chromatograms are not sufficient for positive identification of unknown materials. Heretofore, the sample that was obtained by paper chromatography was insufficient for infrared analysis, and limited the combined use of these techniques. The infrared technique described here ensures identification of microgram quantities of unknown materials which are separated by paper chromatography. ACKNOWLEDGMENT
The authors wish to extend thanks to Otis Childress and Experiment, Inc., for assistance in the fabrication of the microdie; and to Ruth Kayner and
Janie Morris for the preparation and analysis of the samples. LITERATURE CITED
(1) Anderson, D. H., Woodall, K. B., ANAL.CHEM.25, 1906 (1953). (2) Barker, S. A., Bourne, E. J., Stacey, M., Wiffen, D. H., J . Chem. SOC. 1954, 171. (3) Barnes, R. B., Gore, R. C., Williams, E. F., Linsley, S. G., Petersen, E. hf., -&SAL. CHEW 19. 620 (1947).' Dolinsky, M. , J . Assoc. O$c. Agr. Chemists 34, 748 (1951). Frush, H. L., Isbell, H. S., J . Research NatLBur. Standards 50,133 (1953). Greene, F. L., Seligman, R. B., paper presented a t Virginia Academy of Science Meeting, Old Point Comfort, Va., May 1957. Kuhn, L. P., ANAL. CHEM.22, 276 (1950). Kewniann, I
