AC BRIEFS Highlights of the scienitfic and technical articles in this issue
Thenolytrifluoroacetone: Polarographic and Spectrophotometric Behavior, and Dissociation Equilibria. Mechanisms of Electrolytic Reduction
The interrelationships of the various thenoyltrifluoroacetone species, due to hydration, enolization, and dissociation are investigated in terms of the electrochemical behavior and spectrophotometric data. Four polarographic waves are present depending upon the pH and the buffer. This complex polarographic behavior is elucidated by spectrophotometric examination.
Gas Chromatographic benzene Isomers
Analysis
of
Chloronitro-
A gas chromatographic procedure is devised for the separation and analysis of o-, m-, and />-chloronitrobenzenes. Separations are made on synthetic mixtures and on reaction products from the microscale chlorination of nitrobenzene. K. J. B O M B A U G H , Spencer Chemical Co., Merriam, Kan. Anal. Chem. 3 3 , 2 9 ( 1 9 6 1 )
P. J. ELVING and P. G . GRODZKA, University of Michigan, Ann Arbor, Mich. Anal. Chem. 3 3 , 2 ( 1 9 6 1 )
Effect of Electrode Configuration and Transition Time in Solid Electrode Chronopotentiometry
Experimental evidence is obtained regarding electrode configuration and transition time in solid electrode chronopotentiometry. The transition time constant is measured with plane electrodes of different construction and orientation in the solution over a wide range of current densities and transition times. A horizontal, glass-mantled electrode is recommended. A. J. BARD, University of Texas, Austin, Tex. Anal. Chem. 3 3 , 1 1 ( 1 9 6 1 )
Coulometric Generation and Back-Titration of Intermediate Reagents at Controlled Potential. Application to the Determination of Plutonium
Intermediate reagents for secondary coulometric titrations are generated at controlled electrode potential rather than at controlled electrolysis current. This is the basis for a new coulometric technique which offers several advantages over conventional procedures. The technique is applied to the determination of plutonium(VI) with electrolytically generated iron(II). W . D. SHULTS, O a k Ridge National Laboratory, O a k Ridge, Tenn.
Determination of Nitric O x i d e in a Nitric O x i d e - N i trogen System by Gas Chromatography
A simple, precise gas chromatographic method is developed for determining nitric oxide in nitric oxide-nitrogen mixtures. An eight-foot silica gel column is used with a dual-thermistor thermal conductivity cell. Nitric oxide at 1000 to 10,000 p.p.m. in nitrogen is analyzed within 20 minutes time. R. R. SAKAIDA, R. G. RINKER, R. F. CUFFEL, and W . H. C O R C O R A N , California Institute of Technology, Pasadena, Calif. Anal. Chem. 3 3 , 3 2 ( 1 9 6 1 )
Low-Level Radiochemical Separation of Manganese
A radiochemical method for separating manganese is based on the extraction of tetraphenylarsonium permanganate into nitrobenzene. The technique indicates speed and specificity. Pertechnetate, perrhenate, periodate, and perchlorate are removed in preliminary steps. J. M. MATUSZEK, Jr., and T. T. SUGIHARA, Clark University, Worcester, Mass. Anal. Chem. 3 3 , 35 ( 1 9 6 1 )
Anal. Chem. 3 3 , 15 ( 1 9 6 1 )
Adsorption Phenomena and Their Effects on A n alytical Accuracy in Gas Chromatography
Radiochemical Determination of Plutonium in Urine
The effect of an adsorbed carrier on analytical accuracy in gas chromatography is investigated. Peaks of shortest retention time are the most affected. Evidence is given as to how the error arises and how it may be avoided or minimized.
A modified radiochemical procedure is used to determine the plutonium content in urine. Plutonium is cocrystallized with potassium rhodizonate and interfering elements removed with lanthanum salt precipitation and ion exchange. Five to six hours are required for an analysis.
ALLAN WEINSTEIN, The Pennsylvania State University, University Park, Pa. Anal. Chem. 3 3 , 18 ( 1 9 6 1 )
H. V. WEISS and W . H. SHIPMAN, U. S. N a v a l Radiological Defense Laboratory, San Francisco, Calif. Anal. Chem. 3 3 , 3 7 ( 1 9 6 1 )
Gas Chromatography. The Effect of Gaseous Diffusion on Mass Transfer in Packed Columns
Experimental evidence clearly indicates the importance of the effect of gaseous diffusion on mass transfer in gas chromatography columns. Further evidence clarifies the confusion regarding the effects of liquid concentration and gas diffusivity on high performance columns. A more complete equation for H.E.T.P. would permit the systematic design of columns with greater precision. RICHARD KIESELBACH, E. I. du Pont de Nemours & Co., Wilmington, Del. Anal. Chem. 3 3 , 2 3 ( 1 9 6 1 )
Radiochemical Determination of Radium in Urine
Trace amounts of radium-223 in urine are determined by radiochemical technique. The radium is cocrystallized with potassium rhodizonate and purified by ion exchange. This sensitive procedure has the advantages of carrierfree isolation, simple operation, and economy of time. H. V. WEISS and M. G. LAI, U, S. N a v a l Radiological Defense Laboratory, San Francisco, Calif. Anal. Chem. 3 3 , 3 9 ( 1 9 6 1 )
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1961
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BRIEFS X - R a y Rayleigh Scattering Method for Determination of Uranium in Solution
The Rayleigh scattering measurement technique to deter mine high Ζ atoms in low Ζ media is used for the analysis of uranium in solution. The detection of uranium is en hanced by its fluorescence in the energy band yielding the Rayleigh signal increase. J. C. McCUE, L. L. BIRD, C. A. ZIEGLER, and J. J. O ' C O N N O R , Tracerlab, Inc., Woltham, Mass. Anal. Chem. 3 3 , 4 1 ( 1 9 6 1 )
Rapid Method for Separation and Analysis of Radio active Fission Gases
A rapid method is devised for sampling, separating, and gamma spectrometry analysis of short-lived fission gas nuclides. The method is applied to analysis of reactor and fuel processing plants for the quantitative determina tion of xenon and krypton isotopes. R. C. KOCK and G. L. GRANDY, Nuclear Science and Engineering Corp., Pittsburgh 3 6 , Pa. Anal. Chem. 3 3 , 4 3 ( 1 9 6 1 )
Spectrophotometric Determination of Niobium and Molybdenum with 8-Quinolinol in Uranium-Base Alloys
Differential Thermal Analysis and Thermogravimetric Analysis of Fission Product Oxides and N i trates to 1 5 0 0 ° C.
The thermal stability of selected fission product oxides and nitrates at temperatures to 1500° C. is determined by differential thermal analysis and thermogravimetric analysis. The apparatus is modified to permit the use of these analyses at high temperatures. P. F. CAMPBELL, M. H. ORTNER, and C. J. ANDERSON, Vitro Labora tories, West Orange, N. J. Anal. Chem. 3 3 , 5 8 ( 1 9 6 1 )
Automatic Direct-Reading X - R a y Spectrometry. Application to Determinations of Silver
A manual x-ray spectrometer is equipped with adjusted counting and timing circuits to obtain direct analytical results by digital recording. Optimum operating condi tions are presented in the application of the equipment to the determination of silver in photographic films. J. E. M O O R E , G. P. HAPP, and D. W . STEWART, Eastman Kodak Co., Rochester, Ν. Υ. Anal. Chem. 3 3 , 61 ( 1 9 6 1 )
A n Automatic Melting Point Recorder
Niobium and molybdenum are accurately determined by spectrophotometric procedure using 8-quinolinol. After the sample-reagent reaction the quinolinate is extracted with chloroform and measured spectrophotometrically. Fluoride ion is used as a masking agent for uranium. KENJI M O T O J I M A and HIROSHI HASHITANI, Japan Atomic Energy Research Institute, Ibaraki-ken, Japan
An apparatus is described for the automatic recording of melting points. A few milligrams of sample are placed in a capillary tube and a thermocouple piston inserted. The movement of the piston as a function of the tempera ture records the melting process. L. F. BERHENKE, The Dow Chemical Co., Midland, Mich. Anal. Chem. 3 3 , 6 5 ( 1 9 6 1 )
Anal. Chem. 3 3 , 4 8 ( 1 9 6 1 )
Quantitative Radiochemical Analysis by Ion Ex change. Calcium, Strontium, and Barium
Isotopes of calcium, strontium, and barium are separated from rare earths and each other by a modified ion ex change procedure. Quantitative resolution is obtained for cerium-144, calcium-45, strontium-85, and barium133 using 8% cross-linked Dowex 50 resin. The column is operated at room temperature and no cross contamina tion is evident. LEON W I S H , U. S. Naval Francisco 2 4 , Calif.
Radiological
Defense
Laboratory,
San
Anal. Chem. 3 3 , 5 3 ( 1 9 6 1 )
Determination of Uranium in Zirconium Ores. Modification of the Stannous Chloride Method
Quantitative Determination of Low Atomic Number Elements Using Intensity Ratio of Coherent to In coherent Scattering of X-Rays. Determination of Hydrogen a n d Carbon
Low atomic number elements, such as carbon and hydro gen, are determined quantitatively by a new, accurate xray technique. The method is based on the intensity ratio of coherent to incoherent scattering of x-rays. Multiple analyses of carbon and hydrogen in hydrocar bons are made within 20 minutes. C. W . D W I G G I N S , Jr., Bureau of Mines, Bartlesville, Okla. Anal. Chem. 3 3 , 6 7 ( 1 9 6 1 )
A
A modified stannous chloride reduction method is used for determining uranium in zirconium ores. Uranium (VI) is reduced with sodium fluoride instead of orthophosphoric acid and determined by titration with eerie sulfate against a ferrous o-phenanthroline indicator. Interference is eliminated by tributylphosphate extrac tion. K. BRIL and S. HOLZER, Orquima S / A , Sao Paulo, Brazil Anal. Chem. 3 3 , 5 5 ( 1 9 6 1 )
Determination of Sulfur in Gasoline by X - R a y Emis sion Spectrography
The sulfur content of gasoline is determined using x-ray emission spectrography. The method requires no prior knowledge of the sample since the addition technique compensates completely for variations between sample matrices. A determination is accomplished in 15 to 2 5 minutes. R. A. JONES, Ethyl Corporation Research Laboratories, Detroit, Mich. Anal. Chem. 3 3 , 7 1
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BRIEFS Direct Nickel Determinations in Petroleum Oils by X-Ray at the 0.1 -P.P.M. Level An x-ray fluorescence method is used for the rapid deter mination of nickel in refinery streams of varying composi tion. T h e instrument and the p r o c e d u r e are modified to increase the detectable limits to less than 0.1 p.p.m. of nickel. Application is made to 21 commercial samples with results in good agreement with the wet-ash chemical procedures.
Detection of p-Cresol in Spot Test Analysis Microgram amounts of p-cresol are determined qualita tively by spot test technique. T h e />cresol is reacted with diazotized />-nitroaniline and produces a blue color in the presence of magnesium oxide in alkaline medium. Phenols and o- and ra-cresols d o not react. FRITZ FEIGL, Ministerio d a Agricultura, Rio de Janeiro, Brazil, and VINZENZ ANGER, Firma Loba-Chemie, Vienna XIX, Austria. Anal. Chem. 3 3 , 8 9 ( 1 9 6 1 )
C. C. HALE and W . H. K I N G , Jr., Esso Research and Engineering Co., Linden, N. J. Anal. Chem. 3 3 , 7 4 ( 1 9 6 1 )
Polarography in Liquid A m m o n i a above Its Critical Temperature Estimating Thermal Stability of Experimental Poly mers by Empirical Thermogravimetric Analysis Experimental polymers of broadly divergent chemical nature and decomposition mechanisms are evaluated by thermogravimetric analysis in an inert atmosphere. A comprehensive index of thermal stability obtained under procedural conditions affords a summary of consistent information.
Anhydrous liquid ammoniate of LiC10 4 was prepared and its physical properties determined. T h i s medium is used for the p o l a r o g r a p h i c measurements of liquid ammonia above its critical temperature. WLODZIMIERZ HUBICKI and MICHALINA M a r i a e Curie Sklodowska, Lublin, Poland
DABKOWSKA,
University
Anal. Chem. 3 3 , 9 0 ( 1 9 6 1 )
C. D. DOYLE, G e n e r a l Electric Co., Schenectady, Ν. Υ. A n a l . Chem. 3 3 , 7 7 ( 1 9 6 1 )
Failure of Alkaline Methods to Measure Degree of Polymerization of Carbohydrates. Comparison with Chlorite Method. Comparative studies of alkaline methods indicate a failure to measure the degree of polymerization of carbohydrates. Over consumption of all reagents used is established and some excesses are as high as 75 fold. Samples used in analyses are dextrans, amylopectins, araban, and polygalacturonide. H. F. LAUNER a n d YOSHIO TOMIMATSU, Western Regional Research L a b o r a t o r y , A l b a n y , Calif. Anal. Chem. 3 3 , 7 9 ( 1 9 6 1 )
The 3-Methyl-2-benzothiazolone Hydrazone Test. Sensitive N e w Methods for the Detection, Rapid Estimation, and Determination of Aliphatic Aldehydes A new colorimetric method using 3-methyl-2-benzothiazolone hydrazone as reagent, determines microgram amounts of water-soluble aliphatic aldehydes. T h e dye obtained has a maximum absorbance at 63 5 ιημ. Spot test, paper, silica gel, and others are several techniques employing this reaction for the estimation and detection of aldehydes. EUGENE S A W I C K I , T. R. HAUSER, T. W . STANLEY, and ELBERT, Public Health Service, Cincinnati 2 6 , O h i o
WALTER
A n a l . Chem. 3 3 , 9 3 ( 1 9 6 1 )
Determination of Anthraquinone in Capacitor Di electrics
N e w Rapid Method for the Determination of Nickel in Ferrous and Ferromagnetic Metals
A polarographic method is used to determine anthra quinone in capacitor dielectrics. Anthraquinone yields a well defined polarographic wave in a solvent of 3 to 2 parts chloroform and methanol. Hydrochloric acid is used to shift the wave to a less negative potential, thereby eliminating interference from the dielectric.
A titrimetric method is developed for determining nickel in ferrous and ferromagnetic metals. T h e sample is dis solved in nitric acid and the nickel precipitated as hexamminoperchlorate and titrated with standard cyanide solution.
P. D. G A R N and M. C. BOTT, Bell Telephone Laboratories, Inc., M u r r a y Hill, N. J. Anal. Chem. 3 3 , 8 4 ( 1 9 6 1 )
Determination of Water in 1,1-Dimethylhydrazine, Diethylenetriamine, and Mixtures
C. L. LUKE, Bell Telephone Laboratories, Inc., M u r r a y Hill, N. J. Anal. Chem. 3 3 , 9 6 ( 1 9 6 1 )
Determination Mercury(ll)
of
Mercaptans
by
Titration
with
A near-infrared and a gas-liquid chromatographic method are developed for determining trace amounts of water in alkylhydrazine and alkaline amines. T h e meth ods are evaluated and compared using several synthetic mixtures of 1,1-dimethylhydrazine and diethylenetri amine. T h e chromatographic procedure is limited to samples of less than 7 % water by weight.
A titrimetric procedure using mercury (II) perchlorate as titrant is employed for the rapid determination of mer captans. T h e end point is detected visually or potentiometrically using thio-Michler's ketone indicator o r a mercury indicator electrode, respectively. Sulfur, sulfide, iodide, cyanide, and thiocarbonyl c o m p o u n d s interfere.
H. G . STREIM, E. A. BOYCE, and J. R. SMITH, Picatinny Arsenal, Dover, N. J. Anal. Chem. 3 3 , 8 5 ( 1 9 6 1 )
J. S. FRITZ and T. A. PALMER, Iowa State University o f Science and Technology, Ames, Iowa Anal. Chem. 3 3 , 9 8 ( 1 9 6 1 )
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BRIEFS Spectrophotometric Determination of Manganese in Gasoline
Fluorescence Analyses Hydrocarbons
for
Polycyclic
Aromatic
A rapid, accurate, and interference-free spectrophoto metric method is developed for determining manganese in gasoline. T h e antiknock c o m p o u n d , A K - 3 3 X , contain ing bound manganese is decomposed and the manganese extracted and oxidized t o permanganate, and the maxi mum absorbance measured at 52 5 πΐμ.
A fluorometric p r o c e d u r e is used for the identification and analysis of mixtures of polycyclic hydrocarbons. T o minimize the effects of quenching, self-absorption, and localization, the optimum solute concentration for several aromatic h y d r o c a r b o n s in hexane was determined o n the basis of their absorption of the excitation energy at 365
Ε. D. STEINKE, R. A. JONES, and MANUEL BRANDT, Ethyl Corp., Detroit, Mich. Anal. Chem. 3 3 , 101 ( 1 9 6 1 )
J. H. CHAUDET and W . I. KAYE, Tennessee Eastman Co., Kingsport, Tenn.
The Formation of Hydrogen Peroxide in Alcohols. Its Effect on the Extraction of Chelates of Benzohydroxamic Acid
Colorimetric Method for Continuous Recording Analysis of Atmospheric Fluoride. Test Chamber and Interference Studies with the Mini-Adak Analyzer
A colorimetric procedure is devised for determining trace amounts of h y d r o g e n peroxide in alcohols. Hydrogen peroxide destroys the benzohydroxamic acid chelates of uranium, vanadium, and i r o n when dissolved in alcohol. Steps to eliminate h y d r o g e n peroxide formations are out lined. C. E. MELOAN and W . W . BRANDT, Purdue University, L a f a y e t t e , Ind. A n a l . Chem. 3 3 , 1 0 2 ( 1 9 6 1 )
Spectrophotometric Determination of Traces of Hy drogen Peroxide A spectrophotometric method for determining hydrogen peroxide is based on the destruction of benzohydroxamic acid chelates of uranium and vanadium. T h e decrease in color intensity of the metal chelate is directly p r o p o r tional to the amount of hydrogen peroxide present. Hydroperoxides and dialkyl peroxides d o not interfere. C. E. MELOAN, M. MAUCK, and C. HUFFMAN, Kansas State University, M a n h a t t a n , Kan. Anal. Chem. 3 3 , 1 0 4 ( 1 9 6 1 )
m/i.
A n a l . Chem. 3 3 , 1 1 3 ( 1 9 6 1 )
Tolerance and response data are obtained pertaining to the modified zirconium-Eriochrome Cyanine R fluoride reagent toward c o m m o n atmospheric pollutants. Only aluminum, phosphate, and sulfate are considered possible sources of interference, with phosphate being the most significant. D. F. A D A M S , R. Κ. ΚΟΡΡΕ, and Ν. Ε. ΜΑΤΖΕΚ, Washington State Uni versity, Pullman, W a s h . Anal. Chem. 3 3 , 1 1 7 ( 1 9 6 1 )
Thermometric Precipitation Titration of Calcium in the Presence of Magnesium. Kinetic Masking and Application to Limestone Analysis A rapid and accurate thermometric precipitation titra tion technique is used to determine calcium in the pres ence of magnesium. T h e sample, at p H 8 and under con trolled temperature, is titrated with 0.2ΛΪ ammonium oxalate. A well-defined thermometric titration curve is obtained from the precipitation of calcium oxalate. T h e method is applied to limestone and dolomite samples. JOSEPH JORDAN and E. J. BILLINGHAM, Jr., The Pennsylvania State University, University Park, Pa. Anal. Chem. 3 3 , 1 2 0 ( 1 9 6 1 )
Flame Photometric Determination of Copper in Mineral Mixes. Ion Exchange Technique for Sample Preparation
Determination of Unsaturation in High Molecular Weight Fatty Nitrogen Derivatives. Modification of the Wijs Iodine Value Method
Use of an anion exchange resin and p r o p e r chloride ion concentrations permit quantitative separation of copper from other ions. T h e copper chloride eluted from the exchange resin can be used for flame photometry. T h e procedure eliminates interferences which complicate flame excitation determination of copper. It is effective and reliable for determination of copper in complex mineral mixtures.
T h e degree of unsaturation in high molecular weight fatty nitrogen derivatives is determined by a modified Wijs procedure. T h e modifications eliminate high iodine values and end point difficulties encountered with other procedures.
W . G . SCHRENK, KENTON GRABER, and RUSSELL J O H N S O N , Kansas State University, M a n h a t t a n , Kan. A n a l . Chem. 3 3 , 1 0 6 ( 1 9 6 1 )
A Miniature Electrostatic Precipitator for Sampling Aerosols. Theory and Operation Particulate matter in gases, such as aerosols, is deter mined by an electrostatic precipitation technique. A miniature electrostatic precipitator is developed and equations given to validate its effectiveness. T h e method assumes monodisperse spherical particles and is there fore subject to this limitation. M Y R O N ROBINSON, U. S. Army Chemical Corps., Fort Derrick, Fred erick, M d . Anal. Chem. 3 3 , 1 0 9 ( 1 9 6 1 )
A. J. MILUN, G e n e r a ! Mills, Inc., Minneapolis 1 3, Minn. Anal. Chem. 3 3 , 1 2 3 ( 1 9 6 1 )
Extraction of Zirconium with Di-n-butyl Phosphate and Direct Determination in the Organic Phase with 1-(2 Pyridylazo)-2-naphthol. Application to Fluo ride Solutions T h e separation and determination of zirconium in alu minum-magnesium alloys is accomplished by a sensitive spectrophotometric procedure. T h e sample is dissolved in fluoboric acid-hydrochloric acid and zirconium ex tracted with di-K-butyl phosphate in chloroform. T h e reaction with l-(2-pyridylazo)-2-naphthol yields a red color with maximum absorbance at 5 5 5 ιημ. Fluoride is complexed with ammonium nitrate and does not inter fere. R. F. ROLF, The Dow Chemical Co., M i d l a n d , Mich. Anal. Chem. 3 3 , 1 2 5 ( 1 9 6 1 )
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BRIEFS Simplified Determination of Strontium-90. Preferential Extraction of Yttrium w i t h Tributyl Phosphate
NOW from...
JARRELL-ASH
Low levels of the radionuclide, strontium-90, are determined by a rapid, simple radiochemical procedure. The sample is dissolved in acid and the radionuclides are precipitated; this is dissolved in nitric acid and extracted with tributyl phosphate which removes interfering yttrium and rare earths. R. J. VELTEN and A. S. GOLDIN, U. S. Department of Health, Education, and Welfare, Cincinnati 26, Ohio Anal. Chem. 33, 128 (1961)
Couiometric-Acidimetric Acetic Anhydride
Titration
of
Fluoride
in
A coulometric-acidimetric titration procedure is used for determining fluoride and total base in mixtures. The titration is conducted in a sodium perchlorate-acetic anhydride medium containing acetic acid. The end point is measured potentiometrically as the fluoride is titrated with perchloric acid generated from a mercury anode. W. B. MATHER, Jr., and F. C. ANSON, California Institute of Technology, Pasadena, Calif. Anal. Chem. 33, 132 (1961)
Compare the features of the Jarrell-Ash GLC-6 Chromatograph with any other. You'll see that it offers the latest proven advances in chromatography. • Separate heaters and temperature controls for injector block, oven and detector.
Thermistor Micromethod for Molecular Weight
Molecular weight determinations of certain organic compounds are made using a sensitive thermistor micromethod. Twin thermistor bridge is constructed to measure the temperature difference resulting from difference in solvent activity between drops hanging on a thermistor. ABRAHAM WILSON, LOUIS BINI, and ROBERT HOFSTADER, American Cyanamid Co., Bound Brook, N. J. Anal. Chem. 33, 135 (1961)
Microtechnique for the Infrared Study of Solids. Diamonds and Sapphires as Cell Materials
A cell utilizing diamond or sapphire windows is used to obtain the spectra of various solids and corrosive liquids in the 2- to 35-micron region. The method is a microtechnique giving spectra for specimens weighing as little as 4 micrograms. Spectra are obtained in the visible and ultraviolet regions with ease and rapidity. E. R. LIPPINCOTT and F. E. WELSH, University of Maryland, College Park, Md., and C. E. WEIR, National Bureau of Standards, Washington, D. C. Anal. Chem. 33, 137 (1961)
Detection a n d Estimation of Polyoxyethylene Glycol in Nonionic Surfactants by Ascending Paper Chromatography
A qualitative and semiquantitative paper chromatographic procedure is used to detect and estimate polyoxyethylene glycol in nonionic surfactants. An ascending chromatogram is developed and the spot detected by spraying with modified Dragendorff reagent. M. E. GINN, C. L. CHURCH, Jr., and J. C. HARRIS, Monsanto Chemical Co., Dayton, Ohio Anal. Chem. 33, 143 (1961)
• Column oven accommodates a variety of high efficiency columns. • Columns may be quickly and easily changed. • Separately heated injection block for " f l a s h " vaporization of sample from room temperature to 350° C. • Convenient micrometrically adjustable sample splitter divides the sample into reproducible ratios. • Column oven may be' maintained within 0.5° C with boost control for rapid heating or temperature programming to 250° C. • Detector may be set for any temperature range from room to 250° C. • It is available with a choice of interchangeable detectors: micro argon diode and triode detectors with choice of Ra 226, Sr 90 or tritium emitters; flame; even the experimental electron capture detectors are available for interchangeable use in the detector mount. • This latest Jarrell-Ash contribution to the field of gas chromatography is now priced for even the most modest laboratory budget. All of the Jarrell-Ash detectors, ovens, injection blocks, columns, sample splitters etc., are available as separate components for those who may wish to modify or modernize existing equipment or assemble their own chromatographs. For those engaged in the study of lipid metabolism or fatty acid chemistry, remember that our W. G. Pye Argon Chromatograph is the standard instrument for this work. Write us today for further information on the equipment or component that suits your needs.
JARRELL-ASH
COMPANY
2 6 Farwell Street, Newtonville 6 0 , M a s s a c h u s e t t s COSTA MESA, CALIF. ATLANTA, GEORGIA DEARBORN, MICHIGAN SAN MATEO, CALIF. PITTSBURGH, PENN. NEW BRUNSWICK, N. J. LOMBARD (CHICAGO) ILL. DALLAS, TEXAS TORONTO, CANADA ZURICH, SWITZERLAND Circle No. 162 on Readers' Service Card VOL 33, NO. 1, JANUARY 1961
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