Formula Units per Rhombohedral Cell. 2. Formula Weight. 1035.53. Density. 2.505 grams per cc (calculated; weight of unit atomic weight 1.6602 X gram), 2.440 (measured).
OPTICAL PROPERTIES Uniaxial positive. Refractive Indices (5893 A.). no = 1.508 j z 0.001, 1 2 ~= 1.516 f 0.001; geometric mean 1,511. Lorentz-Lorenz refraction 123.8 cc. Colorless.
LITERATURE CITED
(1) Larsen, E. s.3 Berman, H., U.S. Geol. Surv. Bull. 848, 31 (1934).
WORK done under auspices of Atomic Energy Commission.
Gulf Coast Spectroscopic Group HE 21st meeting of the Gulf Coast TSpectroscopic Group was held September 28, 1956, a t Baton Rouge, La., when the following papers were presented.
Solid Phase Transitions of Waxes. Application of Infrared Spectroscopy. J. M. MARTIN,Shell Oil Co., Houston, Tex. Melting point and transition temperatures of commercial paraffin waxes were measured by an infrared technique. The effect of temperature and certain impurities on the infrared absorption of normal paraffin waxes was discussed. Properties such as ductility change with crystal structure. These properties change markedly in the transition range of the wax. The 13.7-micron component of the paraffin wax infrared spectrum was temperature-dependent. Above the transition temperature a singlet is shown; below, a doublet. This absorption is used for determining the transition temperature and melting point of the wax. Plots of temperature us. absorption are made at a single wave length. Deuterium Determination with M r a red. H. L. SPELL,The Dow Chemical Co., Freeport, Tex. -4rapid method for the determination of DHO in water a t or below normal abundance was described. A wide slit, high gain, and maximum out ut from the source of a Perkin-Elmer d o d e l 112 infrared spectrometer are used. The 3.98micron 0-D absorption band is in a relatively transparent region of the water spectrum and this band is used for the analysis. Scattered light, effect of temperature, effect of slit width, and impurities in the samples were discussed. Survey of Analytical Applications of Solid-state Infrared Spectra. W. F. HAYNER,Monsanto Chemical Co., Texas City, Tex. Solutions, mulls, films, and pressed disks were discussed. Antimony trichloride was tried as a solvent for difficultly soluble materials without much success. Elevated temperatures are required to keep it in the molten state and trouble was encountered from im urities and hygroscopicity. &any internal standards are available for the mull technique-calcium carbonate, hexabromobenzene, lead thiocyanate, and potassium nitrate. The infrared spectrum of a compound may be different in solution and in the solid state. Techniques for making films include
166
ANALYTICAL CHEMISTRY
slicing, pressing, and rolling. A solid film may be made by sublimation of the compound onto a rock salt window. Potassium thiocyanate is a good internal standard for potassium bromide work.
Analysis of Unsaturated Hydrocarbons by Low Voltage Mass Spectrometry. S. H. &STINGS, Humble Oil & Refining Co., Baytown, Tex. Operation of a mass spectrometer a t an ionizing voltage of 6.9 volts instead of the Effects in Solid-state Infrared Spectra usual 50 to 70 volts gives only the parent of Cyanuric Acid. IT. 31. PADGETT, peaks of olefins and aromatics. The Monsanto Chemical Co., Texas City, energy of the electrons is not sufficient to Tex. cause cracking nor ionization of saturates. Three different spectra were obtained This simplifies the mass spectrum and fqr cyanuric acid by three different techmakes calculation of the olefins and aroniques: ( A ) sublimed, ( B ) potassium matics easier [ANAL. CHEX. 28, 1248 bromide disk, and (C) sodium chlo(1956)l. ride disk. It was thought a t first this was due to polymorphism or solid solution Processing of Mass Spectrometer Data formation. A is the normal spectrum on Electronic Computers. J. M. KIBBEE, for cyanuric acid. Spectrum A can be I.B.M., Houston, Tex. obtained with potassium bromide disks Multicomponent mass spectrometer if a mixing time of only’30 seconds is used. computations were discussed. There is a After several hours there was a changematrix inversion program set up in Housover from A to B. This eliminated solid ton. solutions. A t elevated temperatures and a t liquid nitrogen temperature the change from A to B was more rapid than a t room The CEC 26-201 Chromatograph. 11. V. PERRY,CEC, Houston, Tex. temperature. It was thought that C was the spectrum The instrument design and performance of the dihydrate. But the dihydrate was were described. The units can operate up prepared and the potassium bromide to 25O0C., but no column material was spectrum run; B was obtained. C was recommended a t this temperature. Several obtained from sodium chloride disks. oven units can be used for one control unit. The conclusion is that effect is probably due to ion interchange. Operating Your Gas Chromatographic Unit. K. H. CLOUGH,Curtin, Houston, Quantitative Analysis with 112-G ForeTex Prism Grating Spectrometer. JACK BAUDERN, Perkin-Elmer Corp., Yew Orleans, Displacement and elution analysis was discussed. A preprint included a bibliLa. ography with 144 references. Design and performance of the instrument were described. Much improved I n the open discussion on gas chroresolution is obtained with this instrument matography activated charcoal was over the older Model 112. (Sales literature is available from Perkin-Elmer.) recommended for separation of carbon dioxide, if other components are not too Open discussion on infrared and ultraheavy. violet brought out the points t h a t diIn discussion of separation of CZ’St o methyl formamide is useful as a solC4’s, two recommendations of column vent for difficultly soluble compounds. material were made: dimethyl formSulfur is a possible solvent in infrared amide and silica gel or Dow Corning analysis of difficultly soluble comsilicone oil 200. pounds. I n separation of CBfs three recomDeuterium Determination by Mass mendations on columns were made: The Dow Spectrometer. R. B. LEBLANC, 1.5 squalene on charcoal, Perkin-Elmer Chemical Co., Freeport, Tex. d and B column, and m-tricresyl phosThe determination of deuterium in hyphate. drogen was described. The Hs + ion interFor the separation of hydrogen, feres with the HDf ion. High filament methane, carbon monoxide, and nitroemission current, high pressure and relatively higher ion repeller voltage are used gen charcoal was recommended. For for the analysis. The ratio of deuterium hydrogen, Cl to C6’s silicone oil and to hydrogen a t zero pressure is obtained dimethyl formamide were recomfrom plots of the ratio of mass 3 to mass 2 mended. us. mass 2.
