1054 Determination of Calcium in Lubricating Oil by Flame Spectrophotometer. M. L. MOBERG, V. B. WAITHMAN, W. H. ELLIS,AND H. D. DeBois, California Research Corp. A rapid method for determining the calcium content of oil has been devised using the flame spectrophotometer. A Beckman instrument was used for this work. The sample is dissolved in benzene and the resulting solution atomized into the flame, the intensity at 6260 A. wave length measured, and the intensity compared with that given by a pair of standards. At concentrations of 2 per cent or less sample in benzene, variations of viscosity of the sample have negligible effect on the accuracy. The presence of phosphorus not combined with the calcium will give no interference. Phosphorus chemically combined with the calcium will cause low results. The presence of sodium, sulfur, zinc, and lead has no effect.
ANALYTICAL CHEMISTRY lolo. The second of these methods was described in the present paper. The isotopic dilution method involves dissolving the sample to be analyzed, adding a known amount of isotope tracer, and measuring the isotopic composition of the resulting mixture with a mass spectrometer. The isotopic composition gives the weight of the element or elements in question in terms of the weight of sample dissolved and the weight of the tracer added. The method is independent of chemical yields in any processing of the sample-i. e., it does not involve an undetermined systematic error. Examples of the technique were shown in which the sensitivities were better than 1 part per billion.
Discussion included remarks by A. E. Cameron, Union Carbide and Carbon Corp., Oak Ridge, Tenn.
A Modified Recording Flame Photometer. W. H. KINGAND W. M.
PRIESTLEY, Esso Laboratories. A Beckman flame photometer has been modified for use as a recording instrument and has been in service for over a year in this laboratory. The use of a recording technique has proved to be advantageous in flame photometer work since zero drift, sensitivity drift, and aspirator change difficulties are compensated by a recording technique. The flame spectrum of a sample may be scanned in a few minutes, thereby presenting a rapid qualitative analysis. Unexpected elements have shown up in recorded flame spectra which otherwise may have been overlooked. The instrument described here uses a photomultiplier detector which permits operation at extremely low light intensity levels. Through this sensitive detector system the minimum detectable amounts of many elements have been lowered.
Philadelphia Analytical Group Officers The following officers of the Analytical and Microchemical Group of the Philadelphia Section, AMERICAN CHEMICAL SOCIETY, have been elected for 1951-52. Chairman, Albert B. Sample, Bryn Mawr Hospital Vice Chairman, Walter Clavan, Pennsylvania Salt Manufacturing Co. Secretary, Ruth Savacool McCard, Smith, Kline & French Laboratories Executive Committee, William G. Batt, Biochemical Research Foundation; Herbert K. Alber, S r t h u r H . Thomas Co.; 0. Davis Shreve, E . I. d u Pont de Semours ti Co.
The Flame Photometer in the Analysis of Water and WaterFormed Deposits. R. K. SCOTT,V. M. MARCY, AND J. J. H R O N A ~ , Hall Laboratories, Inc. The use of the flame photometer in the determination of sodium and potassium in industrial water and water-formed deposits is discussed. The flame photometer is shown t o give results of sufficient precision and accuracy for routine determinations without the numerous separations required in classical chemical analysis. Raw waters, treated xaters, and boiler maters are run without preliminary treatment. Deposits require only solution of the sample, the procedure for which is presented. Since publication of the program of analytical papers of t h e Since a single flame photometer determination is a matter of 10 to 15 see. it becomes entirely practical to determine approximately the Gordon Research Conferences [ANAL.CHm., 23, 812 (1951)] sodium or potassium content of the sample, run standard samples to changes have been made in the program on ‘‘Current Trends in bracket the estimated concentration, and interpolate linearly, for Analytical Chemistry,” t o be presented at New Hampton, N. H. t.he final value. A complete determination. including calculations, can thus be done in a matter of a few minutes. August 6
Gordon Research Conferences
SYMPOSIUM ON CHEMICAL ANALYSES OF INORGANIC SOLIDS BY MEANS OF MASS SPECTROMETER
Mass Spectrometric Analysis of Solids with the High Frequency Spark. J. A. HIPPLE,National Bureau of Standards, Washington, D. C. A method of using a direct electrical detection with a source employing a high frequency spark was described. The erratic fluctuations of the source are monitored with an auxiliary electrode and the ratios of the various types of ions to this monitor current are recorded as the magnetic field is varied to scan the mass spectrum across the exit slit of the spectrometer. The successful application of this technique to the analysis of some solid samples of known chemical composition was discussed. Mass Spectrometric Analysis of Copper for Cuprous Oxide Rectifiers. W. M. HICKAM, Westinghouse Research Laboratories, East Pittsburgh, Pa. A number of analyses of Chilean coppers used for cuprous oxide rectifiers have been made by mass spectrometric analysis of a molecular beam obtained by vaporization of the copper samples, and mass spectrometric analysis of gas obtained using vacuum fusion techniques. The results from a number of analyses were presented and correlation with rectifier performance was indicated. Isotopic Tracers as an Aid to Chemical Analyses with the Mass Spectrometer. MARKG. INGHRAM, Argonne National Laboratory, Chicago, Ill. There are two fundamentally different methods of doing chemical analyses with the mass spectrometer. The first is the Dempster hot spark method, and the second is the isotopic dilution method. The former has the advantage that it can analyze for “every” element present in a solid sample without chemical manipulation. The second, while it requires chemical manipulation, has sensitivities of lo3 to 104 times that of the hot spark method-of the order of 1 part in
Philosophy of Trace Analysis. S. E. Q. ASHLEY, Genera1 Electric Co. Logarithmic Diagrams in Trade Analysis. J. GILLIS,University of Ghent Colorimetric Trace Analysis. J. H. YOE, University of Virginia
August 7 Trace Analysis of Petroleum Products. H. LEVIN,T h e Texas Co. Fluorescence Analysis. C. E. WHITE, University of Maryland Spot Test Methods. P. IT.WEST, Louisiana State University
August 8 Coulometric Analysis. E. H. SWIFT, California Institute of Technology Coulometric Analysis. 15’. D. C O O K E , Princeton University Electrolytic Trace Analysis Involving Radioactive Indicators. L. B. ROGERS.Massachusetts Institute of Technolonv Trace Analysis Based on Electrochemical Reactions a t L R o t a t e d hlercury Electrode. T. S. LEE, University of Chicago August 9 Radioactive Tracer JIethods. J. F. FLAGG, General Electric Co. Isotopic Dilution Bnalysis. S . TRENNER, Werck ti Co., Inc. August 10 . Institute of Trace Gas A4nalysis. L. K. N A ~ H Massachusetts Technologv I
American Association for the Advancement of Science. Gordon Research Conference, Colby Junior College, New London, N. H., and New Hampton School, New Hampton, N. H., July 23 to dugust 10 International Congress on Analytical Chemistry. United Kingdom, Bugust 8 to 13
