Preparation of Biological Samples for Spectrographic Analysis

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Emission Spectroscopic Determination of Metals in Nonmetallic Samples -2 MSYMPOSIUM o n Emission Spectroscopic Determination of e t a l s in S o n m e t a l l i c Samples Ras held M a y 1 in Chicago

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u n d e r t h e auspices of t h e Bmerican Association of Spectrographers. A b s t r a c t s of t h e p a p e r s presented a r e given here. Yyniposium chairman was J. P. Pagliassotti, Research D e p a r t i n c ~ i tS, t a n d a r d Oil Co. ( I n d i a n a ) , Whiting, I n d . Preparation of Biological Samples for Spectrographic Analysis. LEE SMITH, ERNESTYEAGER, N.4THAN KAUFMAN,FRANK HOVORKA, .4ND THOMAS D . KINNEY,western Reserve University, Cleveland, Ohio. II-IE

T h e quantitative analysis of biological samples requires t h a t large amounts of organic matter be eliminated and t h e mineral constituents be reduced t o a form suitable for analysis with t h e high voltage spark or arc. Wet and d r y methods of oxidizing biological samples were discussed and t h e merits of each technique evaluated in terms of t h e nature of t h e sample and t h e type of analysis desired. Results obtained by various methods of sample preparation were presented in terms of t h e analysis of human tissue and fluids for minor and trace elements with t h e porous cup technique.

t h e copper spark. T h e sensitivity of t h e graphite spark is also compared with t h a t of t h e d.c. arc. T h e precisions of t h e graphite and copper sparks are nearly t h e same. T h e advantages claimed by Eachtrieb for t h e copper spark technique are therefore also realized by t h e graphite spark, but a t lower cost and somewhat greater convenience. T h e adaptation of t h e graphite spark technique t o t h e analysis of solutions of traces of copper, cobalt, and zinc, obtained from plant ash and soil extracts, following preliminary chemical concentration by dithizone, was described. Controlled-Atmosphere Excitation of Trace Elements in Oil. J. P. Research Department, Standard Oil Co. (Indiana), K h i t i n g , Ind. PAGLIASSOTTI,

Emission spectroscopy has been investigated for t h e direct determination of trace metals in petroleum liquids. T h e rotating electrode, which is particularly successful with lubricating oils, was used. Excitation with an interrupted arc under atmospheres of controlled composition has led t o a sensitive analytical method. Typical sensitivities attained are: lead, 2 p.p.m.; phosphorus, 5 p.p.m.: andsilver, 0.1 p.p.m. Low thermal conductivity of t h e electrode shaft contributes t o t h e high sensitivity. Cooling t h e atmosphere makes the method useful for more volatile samples.

Comparative Microspectrographic Study of the Red Blood Corpuscle, t h e Blood Eosinophil, and Other Eosinophilic Granulated Cells. F. W. XRDES A K D F. DURAN-JORDA, Department of Pathology, Booth Hall Hospital, Manchester 9, England.

The Spectrograph a s a Diesel Engine Trouble Shooter, A. C. L. L. KITHAN, American Locomotive c o . , Schenectady

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5 , N. Y. Spectrochemical Analysis of Wear Products in Lubricating Oil.

T h e authors have adapted a direct-vision Zeiss specbrograph t o a n inverted microscope, and have carried out different techniques, using as sources of illumination a mercury vapor lamp t o study t h e light absorption of t h e lines of t h e mercury spectrum and a Point-0-lite t o complete t h e spectrographic experiments with a continuous spectrum. They proceeded t o make a comparative study of t h e light absorption of t h e red blood corpuscle, the eosinophil polymorphonuclear found in t h e peripheral blood, t h e gastric oxyntic cell, t h e Paneth cell found in t h e intestine, and t h e large eosinophilic granulated cell (phagocyte?) found in some human thyroid cysts. -4s a result of their investigations t h e y reached t h e conclusion t h a t t h e group of cells studied gave a light absorption pattern similar t o t h a t produced by t h e red blood corpuscle. These results upheld t h e previous ideas of Duran-Jorda, of a close physiological relationship between these eosinophilic cells and t h e red hlood corpuscle, which has already been demonstrated by t h e same morphological shape of rheir granules as seen in man, llama, and camel, by their cytoplasmatic contents of iron, by leaving similar ashes after microincineration, and by their fluorescence when studied under a n ultraviolet lamp. Thercfore, this comparative microspectrographic study adds more ;upport t o t h e existence of a common physicochemical composition in t h e cytoplasm of t h e red blood corpuscle, t h e blood eosinophil, and the other eosinophilic granulated cells studied.

11. F. HASLERASD B. R. BOYD,ilpplied Research Laboratories, Glendale, Calif.

-1rapid method of determining metallic and additives in lubricating oils is essential for engine wear studies, and as a control t o preventive maintenance. A method of using t h e oil directly, without ashing, by t h e use of t h e ARL Rotrode rotating disk was described. Cadmium naphthenate is added t o each sample of oil as an internal standard. dpproximately 0.5 ml. of sample is required. A complete spectrographic analysis can be made in 10 or 15 minutes. By use of t h e -1RL Quantometer in place of t h e spectrograph, t h e time is reduced t o i minutes or less. Precision a t both low and high levels of concentration is excellent. Complete details of t h e procedure were given.

Use of the Rotating Electrode Technique for t h e Analysis of Wear AND EGON TEODORSON, Products in Diesel Lube Oils. L. 0. EIKREM Jarrell-Ash Co., Boston. Mass.

Aireport was made on t h e sensitivity of the rotating electrode technique in t h e analysis of wear products in Diesel lube oils. T h e paper includes work done on t h e reproducibility of t h e method and on t h e optimum excitation conditions discovered. T h e results of this work were contrasted with experience of t h e Jarrell-Ash laboratory in t h e analysis of Diesel lube oils by other types of excitation. Excitation of Nonmetals by the Activated Arc. J. E . BARSEY11, Research Department, Standard Oil Co. (Indiana), Whiting, I n d .

T h e Spectrochemical Analysis of Beryllium in Ore, Air, and Solutions. WM. J. POEHLMAS, Refiearch Department, -1.0. Smith Corp., Milv,xukee, \Tis.

Excitation of nonmetals by spectroscopic methods has always been difficult because of t h e high ionization potentials involved, and because t h e persistent spectral lines of these elements lie in t h e vacuumultraviolet region. Most techniques for excitation of nonmetals require elaborate high-voltage sources or evacuated electrode chambers t o yield satisfactory results. Sventitskii has developed a device claimed t o produce good excitation of chlorine, bromine, iodine, and sulfur without cornplicated equipment. This instrument, t h e activated arc, has been built and tested in these laboratories. T h e authors have improved t h e original circuit t o give a more stable electrical discharge and better excitation. The technique has been adapted t o t h e analyses of both solid materials and aqueous solutions. Excitation of organic liquids is also poPsible and warrants further study.

.4 spectrographir, method was described for t h e deterinination of herylliuni oxide in heryl ore in the range of 6 to 12%. T h e sample is mixed with iron oxide, lithium carbonate, and graphite, briquetted, and exrited in t h e a.c. spark. T h e amount of beryllium is determined by compaving t h e density of Be 3321.343 t o Fe 3021.073. T h e method of Cholak and Hubbard for t h e determination of beryllium has been extended to a wide variety of industrial solutions and its ~ e n ~ i t i v i increased ty t o 0.00025 microgram of beryllium per milliliter of .ohtion.

Modification of the Copper Spark Method. E. E. PICKETT ASD BOBBYE. HASKINS, University of Missouri, Columbia, Mo. Sachtrieb has described a spectrographic method for analysis of small samples in solution form. T h e solution is evaporated on t h e ends of pure metal electrodes, usually copper, internal standard i. added in similar fashion, and t h e electrodes, with their very small deposits of salts adhering, are sparked. Very high sensitivity and good preri>ion were claimed. T h e authors have found t h a t graphite electrodes, previously impregnated with paraffin, can be used in t h e same manner. T h e sensitivity of t h e graphite spark is approximately t h e same a5 t h a t of

X-Ray Spectroscopic Determination of Niobium and Tantalum in Monazite Ores. D. M . MORTIMORE ASD P. A. Robclass, U. s. Bureau of Mines, Albany, Ore.

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d method was presented for t h e determination of niobium and tantalum in monazite or similar ores. This method involves t.he use of x-ray spectroscopic techniques employing the latest instrumentation. T h e intensity of t h e niobium and tantalum spectra is calciliated and related t o corresponding zirconium and hafnium spectra 997