A GAMMA CELL FOR INFRARED MICROSPECTROSCOPY

Author Institution: The Children's Cancer Research Foundation, Children's Medical Center and; The Children's Cancer Research Foundation, Resarch Laboratory, Polaroid Corp.Infrared spectral data have been reported previously on single crystals, fibers, and $oils.^{1,2}$ In general it is possible to obtain data, with suitable resolution, on such samples weighing between $10^{-5}$ and $10^{-7} grams.^{3}$ We now report a technique for the determination of spectral absorptions of solutions containing about 1 gamma ($10^{-6}$ grams) of solute. The absorption ``cell'' used is a piece of capillary tubing made of silver chloride with a central hole about 0.075 mm in diameter. The cells have lengths of 1 to 1.5 mm and are filled by means of a micropipette. A magnified image of the cell is then projected on the entrance slit of a spectrometer and the spectral data are recorded. Information will be presented on the construction of the cells as well as operational details related to their filling and sealing. Spectra of typical organic compounds will be presented, and the applications of the apparatus to chromatographic processes will be discussed