Emission Spectrograph Research Articles

Trace Metals Analysis on Small Oil Samples

The use of direct reading emission spectrographs is a well known means of analyzing used crankcase oils for trace metals. The analysis can be accomplished without any sample preparation by employing a rotating graphite disc as one of the electrodes. A graphite rod is used as the counterelectrode. The disc, as it rotates, is partially immersed in the sample, and thus a fresh supply of oil is continuously presented to the discharge gap.

Examination of Automobile Paints by Laser Beam Emission Spectroscopy

Abstract An analysis was performed on 112 paint chips of various colors from wrecked, late model automobiles. A laser beam microprobe was used in conjunction with an emission spectrograph in order to determine the applicability of the laser microprobe in forensic paint analysis and the specificity of the emission spectrograph in paint analysis. The emission spectrograph was employed to determine the relative abundances of elements in the surface layers of the paint chips. The laser microprobe attachment permitted the analysis of very small paint chips and the analysis of the surface layers of the multilayer paint chips. The results indicated that of the 112 paints analyzed (a) 11 pairs of paints which were physically identical could be distinguished by the emission spectrograph, (b) 4 pairs of paints which were physically identical were also identical by the emission spectrograph, and (c) 3 pairs of paints which were not physically identical were identical by the emission spectrograph. From the results it was concluded that, although the elemental composition cannot individualize a paint chip, it is a useful forensic technique when supplemented with a microscopic examination.

A Digital Programmer for the Heinrich Miniature Probe Attachment for an X‐Ray Emission Spectrograph

AbstractA solid‐state digital programmer was developed to drive a Heinrich miniature probe attachment for an X‐ray emission spectrograph. This allowed the automated operation of the X‐ray emission spectrograph during analysis of transects in a variety of studies such as: clay films associated with ionic diffusion, ionic distribution in plant tissue, etc.

Emission Spectrographic Determination of Hafnium in Zirconium Dioxide

An emission spectrographic method of analysis is described in which trace quantities of hafnium are determined in zirconium dioxide. The sample preparation, starting with zirconium metal sheet or zirconium dioxide, is discussed in detail. The excitation source used is an ac spark. Quantitation was achieved with a dual grating emission spectrograph. The analytical range of the method for the analysis of hafnium is 5 to 1000 ppm with a relative standard deviation of 9.7%.

Determination of thoria in thorium ores by an emission spectrographic method

The emission spectrograph is used to determine thoria in monazite sand. A sample of only 15 mg is required and yields rapid and accurate results for 2% thoria or less. Of various additives tested as carriers, carbon and MoO 3 were found to be best. A current of 6 A gave a proper rate of volatilization without excessive spattering. The 267.28 nm Mo line was used as internal standard and the 269.24 nm Th line for analysis. Silica and iron sulphide were used as matrix in synthetic samples. Results compared well with those obtained by wet-analysis.

Quercetinase, a dioxygenase containing copper

Summary Quercetinase, a dioxygenase that cleaves the heterocyclic ring of quercetin to yield carbon monoxide and 2-protocatechuoyl phloroglucinol carboxylic acid, was found by the emission spectrograph to contain copper. Iron was not detected. Compounds such as diethyldithiocarbamate and toluene-3,4-dithiol that chelate copper quite specifically were potent inhibitors (10−7 M) whereas 1,2-dihydroxybenzene-3,5-disulfonate (10−2 M) which is quite specific for ferric iron, was not an effective inhibitor. The native enzyme is believed to contain the cupric ion for a color complex with 2,2′-biquinoline was not obtained unless reducing agents such as ascorbate or sodium dithionite were added.

Spectrographic Determination of Elements in Airborne Dirt

An emission spectrographic method is described to determine the concentrations of aluminum, cadmium, calcium, chromium, copper, iron, lead, magnesium, nickel, silicon, tin, and zinc in airborne dirt. A measured volume of air is drawn through a 1 in. filter paper. The filter is analyzed by a direct reading emission spectrograph using a push-up technique to introduce the sample into the analytical gap. Calculations and report writing are performed by a computer. Computer programs aid the data interpretation by annotating the results and by the preparation of summaries and graphs. The precision is approximately ±25% of the amount present at the 3 µg level. Analysis time is about 5 min/sample.

Preparation and characterization of boron films from diborane

The thermal decomposition of diborane, B 2H 6, has been used as the basis for a method of forming adherent coatings of boron on various substrates. The purity and other properties of the films were studied by emission spectrograph, electron microscope and optical techniques. The method of preparation described appears to have advantages compared with established methods.

Elemental Analyses of Plant Leaf Tissue by Several Laboratorie

Abstract Eighteen laboratories reported the analyses of seven plant tissue referee samples for the elements N, P, K, Ca, Mg, Al, B, Cu, Fe, Mn, Na, and Zn. Agreement among the laboratories was good for the elements N, P, Mn, Mg, K, and Ca. Poor agreement was obtained for the elements B and Cu with only fair agreement for Na, Al, Zn, and Fe. The results from this exchange of samples were not too different from those obtained by others in similar studies. Although the probable sources for the variances were not investigated, failure to specify drying and ashing technique, as well as the lack of plant tissue standards from a reliable source, may have contributed to discrepant analyses in some laboratories. Also, analysts need to carefully evaluate calibration and operating techniques, particularly when emission spectrographs are used to perform plant tissue analyses. Exchange of plant tissue referee samples between laboratories can be of assistance to the analyst when plant tissue standards are not available.

A Simple X‐Ray Fluorescence Technique for the Determination of Iron and Manganese in Soils and Concretions

AbstractA simple technique for the determination of Fe and Mn in concretions and soils was developed using X‐ray fluorescence. A 25 mg sample was suspended in a 1% glue‐methyl alcohol solution and transferred to a 4.25‐cm circle of filter paper. The filter paper containing a thin layer of uniformly distributed sample was placed in an X‐ray emission spectrograph for analysis, and highly reproducible and accurate results were obtained. Precision was achieved over a wide range of Fe and Mn oxide contents.

A Direct-Reading Polychromator for Emission Spectroscopy

Construction and use of a photomultiplier-tube direct-reading polychromator for emission spectroscopy is described for application to measurement of spectral line intensities from plumes generated by a ruby laser microprobe. Simultaneous correction for background adjacent to each spectral line measured is provided. Advantages include capability of external precision alignment and the use of optically and electronically matched components for recording the line and background intensities. Although the unit is adaptable to commercial spectrographs, the polychromator constructed was made to fit a Czerny-Turner, f/6.3, emission spectrograph (Jarrell-Ash Co., Waltham, Mass.) which had been designed for photographic recording.

Determination of Mercury in Brine Purification Mud by Emission Spectrographic Analysis

Emission spectrographic analysis by the AC arc powder method was examined in order to find a simple method for the determination of mercury in brine purification mud.The volatilization rate of mercury which depends on the sample composition, could be regulated in a good level by using graphite powder as the diluent.The most suitable carrier which gives the highest sensitivity was found to be Ag2O.From the experimental results above mentioned, a recommendable operating condition is as follows;the sample is mixed with a suitable amount of graphite powder and Ag2O, put into a carbon neck electrode, and then excited by an AC arc of 30 volts and 7 amperes for 20 seconds.The use of Hg I 2536.5Å/Ge I 2533.2Å line pair as the analytical lines is satisfactory.The concentration of Hg to which the present method is applicable is 0.05-1.5%.This method seems to be suitable for routine analysis in a manufactory.

Technique for Microspark Emission Spectroscopy

The analyst is frequently confronted with the problem of analyzing a microscopic local area in a heterogeneous sample. A rapid, inexpensive technique has been developed to analyze a spot as small as 50 μ in diameter with an emission spectrograph. The only accessories required are a microscope, some transparent tape, and a sharp needle. The tape is placed on the sample surface and a hole is punctured at the spot to be analyzed while viewing the sample through the microscope. The sample is then excited with a very short spark in the spectrograph. Using a very fast film it has been possible to make qualitative analyses for both major and minor constituents of a spot as small as 50 μ in diameter on a conducting sample.

Direct-reading emission spectrometry as a geochemical tool

The conventional optical emission spectrograph is compared with the direct-reading emission spectrometer, and shows that the advantages of the latter instrument are such that it should be considered as a means of obtaining quantitative analyses of a large number of elements in a geochemical program involving rocks, minerals or soil samples.An internal standard analytical procedure involving argon-oxygen atmospheres to surround the arc and a sodium metaphosphate buffer is described for a typical geochemical program. The technique is faster and more quantitative than most conventional spectrographic procedures, although the initial cost of the equipment is high.

Plasma minerals in normal and neutron irradiated burros.

PREVIOUS investigations have reported the biochemical and haematological changes produced by exposure of the burro (Equus asinus asinus) to γ-irradiation1–9. Concentrations of plasma iron rise immediately after irradiation4–7, but concentrations of copper do not rise until death, and magnesium concentrations decrease8. When a small, unshielded and uncooled fast reactor became available10, we exposed fourteen burros to neutron irradiation of either the whole body or the torso only at various doses from 100 to 440 rads. The constitution of each dose was about 90 per cent fast neutrons and 10 per cent γ-rays. (Details of the radiation characteristics and dosimetry have already been described9.) The elements analysed in duplicate in dried plasma, using an optical emission spectrograph, are shown in Table 1; the data were processed in a computer using a Fortran system. Analyses for calcium, potassium, chlorine and sulphur were also made by the X-ray fluorescence method11,12.

Determination of Manganese and Zinc in Aluminous Materials, Using Atomic-Absorption Spectrophotometry

Mn and Zn are determinable in Al ores, intermediates, and finished metal by atomic-absorption spectrophotometry, using a particular burner, if suitable separation procedures are employed. Zn may be separated by chloro—anion exchange. Mn is conveniently extracted into chloroform by complexing with 8–hydroxyquinaldine at pH 12. Results from analyses of known samples show that the method is suitable for the calibration of emission spectrographs.

Calcite-aragonite speleothems from a hand-dug cave in Northeast Kansas

Speleothems in the form of stalactites, linear stalactitic growths, flowstone, and crusts, from a hand-dug cave in Northeast Kansas (Sec. 2 NENW, T2S, R22E) are composed of calcite and aragonite. If the estimated age of the cave is correct, i.e., 150 to 200 years old, the stalactites have grown at a maximum rate of 0.20 to 0.15 millimetres per year along their vertical axes. All of the speleothems examined contain about one percent strontium (based on qualitative emission spectrograph analyses). Rate of supply and evaporation of the vadose waters may dictate whether aragonite or calcite is the polymorph that precipitates from the cave waters.

Examination of Very Small Samples, using Emission Spectrography

E. Martin, in 1963, described a method in which sample is compressed in the tip of a graphite pellet and burnt in the arc of an emission spectrograph. An apparatus produced by Messrs. Research and Industrial Instrument Company, Which produces similar pellets is described here. The results obtained from the use of this apparatus have been found to improve the consistency and strength of the emission spectra of very small samples of paint and other materials. Spectra of fragments of paint weighing 50μg are shown to indicate the consistency of the method.

Application of the Emission Spectrograph to the Analytical Needs of the Industrial Hygiene Laboratory

Abstract Examples of unique applications of the principles of emission spectroscopy to industrial hygiene problems are provided. A discussion of qualitative, semiquantitative and quantitative methods of spectrographic analysis is presented. These methods include representative applications which are made for the analysis of the metallic constituents of body tissues and fluids from human and animal subjects, industrial process materials, ores, and environmental dusts and fumes. Brief descriptions of sample preparation techniques required for successful analyses are also presented.

Instrumentation in Industrial Hygiene

A discussion of the many types of samples encountered in industrial hygiene studies, the techniques and instruments used for their collection, the methods used for their preliminary chemical treatment, and the spectrographic instrumentation and techniques employed for the quantitative determination of their trace metallic constituents is presented. In this paper emphasis has been placed on the need to use sharp, clean separation procedures, along with appropriate instrumentation, to meet the analytical objectives in this field, i.e., highly sensitive, precise determinations of minute amounts of chemical substances. The high utility of the emission spectrograph for the analysis of metallic elements has been illustrated with typical examples of analytical applications made in the author's laboratory.