Symposium on applied spectroscopy

Spectrochimica Acta, 1958,

Vol. 10,

pp. 330 to 334.

Pergamon

Press Ltd.,

London

REPORTS OF MEETINGS Symposium on Applied Spectroscopy THE Fourth Annual Symposium on Applied Spectroscopy, sponsored by the Canadian A.ssociation for Applied Spectroscopy was held at Ottawa from 11 to 13 September 1957. The following papers were presented:

1.Emission Spectrometric Analysis GEORGE L. But, Fisher Scientific Co., Pittsburgh, Pennsylvania. Chemical robots for a variety of purposes are in a sense not completely new, but have been produced for some years. As developments in materials, electronics and optics proceed, the degree increases to which fuller automation of laboratory techniques becomes possible both in the technical and economic senses. What the present status is and what may be expected will be discussed in the light of specific instruments, including older as well as quite recent developments in which human participation is minimized.

Automatic analysis:

The use of the Hiker direct-reader in the spectrochemical analysis of aluminium alloys: ROBERT WERNER, R. D. Werner (Canada) Ltd., Oshawa, Ontario. R. D. Werner Co. (Canada) Ltd. have installed a Hilger direct-reader for analytical control of aluminium extrusions. Alloys controlled are mainly 5OS, 65S, lS, 2S, and 3s. An extensive set of tests was run on installation which generally conformed to A.S.T.M. specifications. Results of tests are discussed. Details are presented regarding installation and ease of operation. One point of great significance is that the superintendent of the Remelt Department is able to run his own analysis for re-melt control.

New direct-reading attachment for 20 in. camera. Three meter concave grating spectrograph: ELIOT DuBors and L. 0. EIKREM, Baird-Atomic Inc., Cambridge, Massachusetts. This paper describes the newly developed direct-reading attachment for the Baird-Atomic 3-meter concave grating spectrograph. The standard 20 in. plateholder of the spectrograph is replaced by a “DR box”, which is an assembly containing a focal curve, exit slits, and photomultiplier tubes. Provision is made for reasonably rapid setting of the exit slits on the spectrum lines of interest by use of a special electronic slit-setting attachment used in conjunction with an oscilloscope. A separate cabinet contains the high and low voltage supplies, the measuring circuitry, and the reading units consisting of clocks which may be calibrated to read directly the concentrations of eight different elements at one time. To set up a “DR box” on a completely new problem requires approximately 2-3 hr. After once having been set up a “DR box” may be removed and held in standby status while other work is pursued photographically on the spectrograph. To return to direct reading then requires approximately 10 min. An important contribution to the success of the “DR” attachment is the development by Baird-Atomic Inc., of a servo-monitoring device which automatically and continuously keeps the spectrum lines precisely aligned with the exit slits. This device also makes possible the use of the electronic slit setting attachment. Stability of optical alignment is essential to precise analysis, and the servo-monitor makes possible the fulfillment of this requirement. It is not necessary to control the temperature in the laboratory.

The Quantovac. A direct reading instrument for the analysis of carbon, phosphorus and sulphur: B. R. BOYD, Applied Research Laboratories, Glendale, California. A direct reading polychromator is now in production for the vacuum region of the ultraviolet. 330

Reports of meetings The wavelength coverage is 1600-3300 8, which includes most sensitive lines of P, C, and S, as well as lines of other elements of interest in the metal analysis field. Data will be presented covering the analysis of these important elements in iron base materials.

The use of hydrogen as internal standard in analysis of additives and wear metals in lube oils by direct-reading methods: R. R. THIEME, Jarrell Ash Co., Newtonville, Massachusetts. A method is developed using hydrogen line 4861 A as internal standard in analysis of additives and wear metals in lube oils by direct reading methods. Elements determined are Ag, Al, B, Cr, Cu, Fe, Pb, Si, Sn, Ba, Ca, Zn, in a range dependent on element from 1 p.p.m. to 3000 p.p.m.

From spectrographic plate to permanent record in one simple operation: F. DUFOUR and D. R. JACKSON, Canadian National Railways, Montreal, Quebec. This paper describes the design of a calculator and record card. Using them it is possible to go directly from microphotometer reading to graphical record entry in one simple operation. The interpretation of a spectrographic analysis of used lubricating oil is simplified by graphical presentation of related analyses. This type of calculator and record card may be of value with other routine spectrographic methods, especially when the results are used for quality control. The calculator has 12 separate scales, one for each of the 12 spectra on the plate. Each scale handles 8 determinations. Each record card accommodates up to 52 analyses for 8 elements. Space is provided for written notes and comments. The use of this system of data handling necessitated some changes in the spectrographic technique which was described at the first Ottawa Symposium. These changes in the technique are described. The sources of error inherent in this system of record keeping are evaluated. The system saves clerical labour and eliminates mistakes due to numerical calculations and data transcriptions. An arc method for sample transfer iu spectrochemical analysis: C. J. LEISTNER, General Motors Corporation, Indianapolis, Indiana. This paper will include a survey of foreign literature dealing with the sample transfer method for spectrochemical analysis. An emphasis will be made on its application at the Allison Spectrographic Laboratory for semi-quantitative evaluation of various jet engine components. W. J. BENNETT and E. M. LAW, Northern Electric Co., Lachine, Quebec. G.R.S. elastomer insulations for wire and cable usually contain a variety of inorganic fillers and activators to impart specific electrical and physical properties to the wire or cable. These are in addition to vulcanizing agents, vulcanization accelerators, colour of pigments, softeners, antioxidants, carbon black, etc. which may be compounded into the elastomer. Among the inorganic materials used are clays, calcium, carbonate, zinc oxide, magnesium oxide and lead oxides. The actual amounts of these materials in the compounded and vulcanized elastomer are critical, Spectrochemical methods for the analysis of these inorganic materials in the elastomer have been developed and will be described.

The spectrochemical analysis of inorganic fillers in G.R.S. rubber compounds:

The spectrographic determination of fluorine iu cracking catalyst and the use of the streamingvelocity arc: L. W. GAMBLE, Esso Research Laboratories, Baton Rouge, Louisiana. In the past several years the petroleum industry has been interested in the analysis of fluorine, particularly in catalysis. A spectrochemical method employing a streaming-velocity electrode which has been developed offers a number of advantages; namely,-increased sensitivity, reduced fractional distillation, and improved arc stability. Due to the nature of the arc, an elemental line can be used as an internal standard. The standard deviation is 0.13 at the 1 per cent level.

Application of the spectrograph to agriculture. Molybdenum toxicity: W. M. LANGILLE and K. S. &CLEAN, Nova Scotia Department of Agriculture and Research Foundation, Truro, Nova Scotia. Methods of analysing soil acid plant samples for cobalt, molybdenum and zinc in trace quantities are described. Application of the method pertaining to a molybdenum toxicity

331

Reports of meetings problem in cattle is presented. Data are given to show average values for molybdenum in plant tissue and soil samples from toxic and non-toxic areas. Values for the elements copper, cobalt, zinc, manganese and calcium are also included.

The determination of trace elements in high purity silica: E. S. HODGE

and B. L. MILAN, Mellon Institute, Pittsburgh, Pennsylvania. The investigation of color centers in quartz is greatly aided by spectrographic analysis. Samples have been analyzed by using an addition procedure with Spex Standards to high purity fused silica. Some of the precautions found necessary are described. Typical results are shown which have permitted some interpretations of color center data. Some detection limits found are Cr, Fe, Li, Mg, Mn, Ag, Ti, 1 p.p.m.; Ba, Be, Ca, Ni, 3 p.p.m.; Al, B, Co, Na, 6 p.p.m.; Cd, Pb, and Hg, 60 p.p.m.

Spectrographic determination of carbon in sedimentary rocks, using direct current arc excitation: W. H. DENNEN, Massachusetts Institute of Technology, Cambridge, Massachusetts. Many molecular bands are excited in the usual spectrographic sources, and some permit the determination of “non-spectrographic elements”. Encouraging preliminary results have been obtained in the use of OH3064A for water determination and CN3883A for nitrogen determinations. Carbon may be determined in its various compounds by direct-current arc emission spectrography. When samples are excited in copper electrodes, the carbon in the sample combines with atmospheric nitrogen to form cyanogen, and the bandhead CN3883A is measured. Cathode excitation at 6 A and 50 V provides the best sensitivity for graphitic carbon and carbonates. A coefficient of variation of 13 per cent is obtained. Marked differences of relative intensity are related to the nature of the carbon compound, to the excitation conditions, and to the presence of silica. These matrix variations are controlled by comparing unknown samples with chemically similar standards, maintaining uniform arcing conditions, and diluting samples with quartz. Separate determinations for different compounds of carbon are required. WARING, H. WORTHING and K. W. HAZEL, U.S. Geological Survey, Washington, D. C. Selenium can be determined in pyrite, chalcocite, and marcasite by a spectrochemical method that is simple, rapid, and requires no complicated arrangement of spectrographic equipment or is taken of the new short wavelength radiation chemical pretreatment of samples. Advantage plates (Eastman) and the addition of copper oxide to enhance the selenium lines 203985 A and 2063.78 A. The possibility exists of determining many other elements on the same exposure of the sample. The method has application in the range of 0.0015 to 2 per cent selenium. Test.8 indicated an average difference from the chemical results of 0.07 per cent in the low per cent range, 0.03 per cent in the 0.1 per cent range, 0.005 per cent in the 0.01 per cent range. The relative accuracy of the entire range is about 7 per cent of the concentration.

A spectrochemical method for the determination of selenium: C. L.

N. TOMINGAY, Canadian Capper Refineries Ltd., Montreal East, Quebec. A rapid and accurate procedure is described for the estimation of impurities in solutions, in particular copper refinery tank house electrolytes. The solutions are excited in an a.c.arc discharge on flat surface electrodes which have been treated to provide uniform porosity. Chromium asanexternal standard has been found satisfactory for the determinationof impurities: arsenic, antimony, bismuth, iron, and nickel. The agreement with chemical analysis is excellent. Considerations governing the selection of the internal standard and the type of electrodes are discussed. Spectrochemical analysis of solutions in an a.c. discharge:

Determination of major constituents in alloy steels by spectrographic solution methods: C. A. WAGGONER, Pacific Naval Laboratory, Esquimalt, B. C. In spectrographic laboratories handling a wide variety of metal alloy often impractical to standardize for each form by conventional spark-to-solid

332

sampIe forms, it is methods. Solution

Reports of meetings techniques may provide a useful porous cup and rotating disk in different types of alloy steel. minimize inter-element effects. Results of comparable precision

alternative if samples are readily soluble. Procedures utilizing techniques are described for determining major constituents Cobalt is used as internal standard, and a buffer is added to Solutions are excited by an oscillating spark-like discharge. and accuracy are obtained by the two techniques.

The spectrochemical analysis of arsenic in steels:

J. E. BURGENER, Technical

Toronto, Ontario. A vapour-cup method results are described.

was investigated.

using arc excitation

A method for determination of trace impurities: Haley, Ontario. A method for determining

t,race impurities

2. It&a-red Spectroscopy The Hilger double-beam recording i&a-red spectrometer: J. Laboratories, Toronto, Description, operation

Ontario. and performance

The development

L. R. PITTWELL,

by concentration

Service Laboratories

Dominion

work

Magnesium

and

Ltd.,

and d.c. arc spectroscopy.

E. BURGENER, Technical

Service

of the instrument.

Spectroscopy in an organic research laboratory: G. PAPINEAU, Couture, Ayerst, McKenna & Harrison Ltd., Montreal, Quebec. Infra-red spectroscopy is often the fastest and the most precise method of solving various problems encountered in synthetic organic chemistry. The practical use of group frequencies will be illustrated by various samples. Reference will be made to both qualitative and quantitative methods. Ida-red

The effect of hyperconjugation on -CH, vibrations: G. POULIOT

and C. SANDORFY, University of Montreal, Montreal, Quebec. The infra-red spectra of various compounds containing one or two -CH,-groups in a conjugated environment were measured. The CH,stretching and scissoring bands are shifted Theoretical implications and from their usual positions showing the effect of hyperconjugation. the use of this observation for analytical purposes are discussed.

J. C. BARTLET, Food and Drug Directorate, Ottawa, Ontario. Differential infrared spectroscopy has found widespread use for the quantitative determination of small amounts of an impurity in another material. In principle, the method depends on using a sample of known purity in one beam of a spectrometer and a second sample of the same substance in the other beam. Any difference in the spectrum of the two samples due to impurities will register on the recorder. The use of this technique has now been extended to identification of edible oils and fats. These materials have very similar spectra making identification by normal spectroscopy impossible. By using one oil in the reference beam, other oils may be identified by minor differences in spectra which become apparent by this technique. It is also possible to detect one oil in the presence of another by these spectral differences. The instrumental requirements for this type of analysis are discussed in detail.

DiBerentid ix&a-red spectroscopy as a tool for qualitative as well as quantitative analysis:

R. M. B. SMALL, Polymer Corporation Limited, Sarnia, Ontario. A review is presented of the quantitative, semi-quantitative, and some qualitative analyses that are performed by infrared absorption spectroscopy. Techniques which are peculiar to the analysis or study of high polymers are described. These include (1) the use of solid filme pressecl

Infra-red techniques with polymers:

333

Reports of meetings between plates of silver chloride or mica, (II) differential analysis with films, (III) pyrolysis of intractable materials, (IV) extraction of material containing carbon black and (V) the use of elevated temperatures with crystalline polymers. W. A. E. MCBRYDE, University of Toronto, Toronto, Ontario. The most familiar quantitative application of absorption spectroscopy is in photometric analysis of solutions. This paper will describe several applications of absorptiometry to special cases of interest in general or inorganic chemistry. First, modified analytical procedures will be described applicable to solutions of optical density higher or lower than ideal. Second, applications to the study of acid-base equilibria will be discussed. Then some discussion of the measurement of distribution coefficients between water and an immiscible solvent will be given. This leads to an account of the technique of reversion, which may be applied to advantage in some analyses utilizing extractions, e.g. with dithizone. Finally some procedures will be described which permit measurement of the identity and stability of complexions formed in aqueous solution.

Some applications and innovations in absorption spectroscopy:

3. X-ray Fluorescence Spectroscopy Absorption phenomena and their influence on quantitative fluorescence analysis:

HEINZ RUCK, Pulp and Paper Research Institute of Canada, Montreal, Quebec. The tabulated absorption coefficients are supposed to allow for the fluorescent and scattered radiation only, as holds true for single crystals. In the case of powders, however, several additional effects can enter into the absorption formula as coefficients. These are small angle scattering, primary and secondary extinction (which are related to crystal and grain size), degree of compaction and microabsorption. This calls for a complete revision of the commonly accepted picture of absorption. It requires a redistribution of the intensities allotted for the different phenomena, especially the fluorescent radiation whose angular dependency has been recently discovered by P. M. DE WOLFF. The conditions under which samples of equal chemical composition produce equal amounts of characteristic radiation are pointed out. Variations in sampling techniques are usually responsible for inconsistent results. Precautions to overcome these are given, Furthermore, the bearing of the matrix on the result must be considered.

A new method for the analysis of ores and metallurgical products by X-ray fluorescence: G. R. LACHANCE, Quebec Metallurgical Industries, Billings Bridge, Ontario. A new method has been developed that enables the analysis of ores and metallurgical products to be done very rapidly. The finely ground sample is mixed with aluminum oxide and scanned. From the graph it is possible to calculate the percentage of the constituents detected using simple calculations. Examples of actual analyses are given. F. CLAISSE, Laboratories Branch, Department of Mines, Quebec. The method consists in fusing the sample in a suitable glass, making disks out of it, and part of analysing these by X-ray fluorescence. When the glass has the following composition-l sample, 10 parts of barium peroxide, 10 parts of barium sulfate and 100 parts of fused borax-it has been observed that the matrix effect is practically negligible. The line intensities (background included) are almost linearly related with percentages up to 100. With this method, only one reading per sample is needed to obtain a result of analysis with an accuracy of the order of 0.3 per cent absolute in less than 2 min. For concentrations below 3 to 5 per cent a better accuracy is obtained by fusing 1 part of sample with 20 parts of borax and using an internal standard. A simple technique for making the glass disks is described. The method can be used for ores and rocks (including sulfides), and possibly for metals and alloys.

Sample preparation for accurate X-ray fluorescence analysis :

The

role of the X-ray spectrograph in the copper base alloy industry: G. American Smelting Co., Wilmington,

Delaware.

334

L. CRUMRINE, North