Determination of non-metallic inclusions in metal alloys by spark atomic emission spectrometry (review)

2018 ◽  
Vol 84 (12) ◽  
pp. 5-19
Author(s):  
D. N. Bock ◽  
V. A. Labusov
Keyword(s):  
Spectral Line ◽  
Internal Standard ◽  
Detection Limits ◽  
Radiation Detectors ◽  
Metal Alloys ◽  
Emission Spectrometry ◽  
Direct Production ◽  
Metallic Inclusions ◽  
Dissolved Form

A review of publications regarding detection of non-metallic inclusions in metal alloys using optical emission spectrometry with single-spark spectrum registration is presented. The main advantage of the method - an extremely short time of measurement (~1 min) – makes it useful for the purposes of direct production control. A spark-induced impact on a non-metallic inclusion results in a sharp increase (flashes) in the intensities of spectral lines of the elements that comprise the inclusion because their content in the metal matrix is usually rather small. The intensity distribution of the spectral line of the element obtained from several thousand of single-spark spectra consists of two parts: i) the Gaussian function corresponding to the content of the element in a dissolved form, and ii) an asymmetric additive in the region of high intensity values ??attributed to inclusions. Their quantitative determination is based on the assumption that the intensity of the spectral line in the single-spark spectrum is proportional to the content of the element in the matter ablated by the spark. Thus, according to the calibration dependence constructed using samples with a certified total element content, it is possible not only to determine the proportions of the dissolved and undissolved element, but also the dimensions of the individual inclusions. However, determination of the sizes is limited to a range of 1 – 20 µm. Moreover, only Al-containing inclusions can be determined quantitatively nowadays. Difficulties occur both with elements hardly dissolved in steels (O, Ca, Mg, S), and with the elements which exhibit rather high content in the dissolved form (Si, Mn). It is also still impossible to determine carbides and nitrides in steels using C and N lines. The use of time-resolved spectrometry can reduce the detection limits for inclusions containing Si and, possibly, Mn. The use of the internal standard in determination of the inclusions can also lower the detection limits, but may distort the results. Substitution of photomultipliers by solid-state linear radiation detectors provided development of more reliable internal standard, based on the background value in the vicinity of the spectral line. Verification of the results is difficult in the lack of standard samples of composition of the inclusions. Future studies can expand the range of inclusions to be determined by this method.

Developing the atomic spectrometry techniques for cobalt and nickel analysis

2020 ◽  
pp. 94-101
Author(s):  
V. A. Korotkov ◽  
◽  
T. I. Velikaya ◽  
E. S. Poslavskaya ◽  
◽  
...  
Keyword(s):  
Internal Standard ◽  
Detection Limits ◽  
Atomic Emission ◽  
Atomic Spectrometry ◽  
Atomic Emission Spectrometry ◽  
Emission Spectrometry ◽  
Single Element ◽  
Element Analysis ◽  
Chemical Reagents ◽  
Cobalt And Nickel

The existing methods standardized for to cobalt and nickel analysis, i.e. GOST 13047–2014, GOST 6012–2011 and GOST 8776–2010, don’t correspond to the current and future requirements to these metals in terms of impurities concentration. GOST 13047–2014 provides single-element analysis applications that establish a sample preparation for single element only, takes a lot of efforts and an extremely long time, consume a lot of chemical reagents and are associated with a significant harmful impact on the environment. Being a multielement technique, atomic emission spectrometry with DC-arc spectrum excitation is associated with a high consumption of chemical reagents and a significant environmental impact. It doesn’t allow determining the sulfur and other important impurities. All standard techniques are based on the obsolete principle to dissolve the samples in glass beakers on hot plates. The authors of this paper propose to standardize the methods of atomic emission spectrometry and mass spectrometry (MS) with inductively coupled plasma (ICP) to run cobalt and nickel analysis. 2.5 g samples of cobalt and nickel were proposed to decompose in a mixture of acids in closed polypropylene vessels heated in HotBlock systems at the temperature of 110 оC. This saved up to 5 cm3 of nitric acid and up to 5 cm3 of hydrochloric acid. The solutions of nickel and cobalt were analyzed for impurities on an iCAP 6500 Duo spectrometer at low plasma discharge power and using the base lines as an internal standard. This helped to improve the detection limits of impurities. To select optimal wavelengthes, full spectra of analyzed solutions were captured. Isotope 185Re was chose as internal standard and a collision and reaction cell was used to remove interfering polyatomic ions on an ICP-MS spectrometer iCAP Qc. Nickel and cobalt samples as well as CRMs were analyzed. The impurities detection limits with the current and future cobalt and nickel grades. The methods developed may create the basis for a new GOST standard applicable to cobalt and nickel analysis.

Simultaneous determination of trace elements in serum by energy-dispersive x-ray fluorescence spectrometry.

1984 ◽  
Vol 30 (8) ◽  
pp. 1300-1303 ◽  
Author(s):  
F Rastegar ◽  
E A Maier ◽  
R Heimburger ◽  
C Christophe ◽  
C Ruch ◽  
...  
Keyword(s):  
Analytical Procedure ◽  
Internal Standard ◽  
Detection Limits ◽  
The Other ◽  
Energy Dispersive ◽  
Statistical Distributions ◽  
Polypropylene Film ◽  
X Ray ◽  
Large Numbers

Abstract Energy-dispersive x-ray fluorescence is applied in the analysis of human serum to determine the concentrations of several elements simultaneously with minimal manipulation of the sample. The analytical procedure has been developed with standard sera, and standardization, detection limits, and reproducibility have been established. A 50-microL sample of diluted serum, to which an internal standard has been added, is deposited on a thin (4-microns thick) polypropylene film and analyzed by x-ray fluorescence. We report the statistical distributions of the concentrations of Fe, Cu, Zn, and Br obtained in the population (103 samples) studied, and report detection limits for the other 22 elements studied. The simplicity of the method, the high throughput, and the possibility of automating the measurements make this procedure suitable for screening large numbers of sera.

Determination of Particle Densities and Line Profiles in Plasmas by Resonance Interferometry: A Feasibility Study using Computer Simulated Refractivity Data

1995 ◽  
Vol 50 (10) ◽  
pp. 902-914 ◽  
Author(s):  
C. Haas ◽  
G. Pretzier ◽  
H. Jäger
Keyword(s):  
Spectral Line ◽  
Feasibility Study ◽  
Particle Density ◽  
Detection Limits ◽  
High Accuracy ◽  
Line Profiles ◽  
Actual Problem ◽  
Density Determination

AbstractThe principles of resonance interferometry are described with regard to two applications: High accuracy particle density determination within plasmas and interferometrical determination of spectral line profiles. The usability of this technique is investigated numerically, and physical limits are given for the regions in which resonance interferometry may be employed successfully. The discussion and the results are helt general for making it possible to decide whether or not to apply this method for an actual problem. An example (an object being longitudinally homogeneous with respect to the direction of light: end-on observation) shows how to use the presented results for calculating the detection limits of the method for a given object geometry.

Determination of carbon in solidified sodium coolant using new ICP-OES methods

2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Tomáš Vaculovič ◽  
Vítězslav Otruba ◽  
Oldřich Matal ◽  
Viktor Kanický
Keyword(s):  
Inductively Coupled Plasma ◽  
Internal Standard ◽  
Optical Emission ◽  
Sample Surface ◽  
Bulk Sample ◽  
Emission Spectrometry ◽  
Icp Oes ◽  
Inductively Coupled ◽  
Carbon Dioxide Reaction

AbstractNew methods for the determination of carbon in sodium using laser ablation inductively coupled plasma optical emission spectrometry (LA-ICP-OES) and ICP-OES with pneumatic nebulisation (PN-ICP-OES) were developed. The determination was required for the study of the carbon dioxide reaction with molten sodium at high temperatures (300–600°C). After exposition to CO2, the solidified sodium sample was subjected to direct solid analysis by LA-ICP-OES and to solution analysis. For the determination of carbon in the sodium sample surface layer by LA-ICP-OES, three different matrices containing sodium were tested (NaCl, NaF, and Na2B4O7 · 10H2O) as calibration pellets. The calibration dependences were improved using sodium as the internal standard. Average carbon content in the sodium bulk sample was determined by PN-ICP-OES after the sample dissolution by water vapour.

Evaluation of the Time-Resolved Spark for the Determination of Sodium, Potassium, and Calcium in Microsamples

1989 ◽  
Vol 43 (4) ◽  
pp. 697-702 ◽  
Author(s):  
John T. McDonald ◽  
J. C. Williams ◽  
James C. Williams
Keyword(s):  
Shot Noise ◽  
System Performance ◽  
Internal Standard ◽  
Detection Limits ◽  
Performance Data ◽  
Sodium Potassium ◽  
Time Resolved ◽  
Noise Limit ◽  
Shot Noise Limit

This paper describes the evaluation of a time-resolved graphite spark source emission spectrometer built for the purpose of determining Ca, Na, and K in nanoliter volume samples of renal fluid. Subnanogram detection limits calculated from the working curve slope and the uncertainty of the sample signal are reported for Ca, Na and K; these detection limits are some three orders of magnitude higher than the shot noise limit. With the use of Li as an internal standard, working curves from 0 to 1 ng of Na, K, and Ca are shown. System performance data are given, and the utility of the analysis is discussed.

Use of a Prior-Oxidation Procedure for the Determination of Iodine by Inductively Coupled Plasma-Atomic Emission Spectrometry

1987 ◽  
Vol 41 (7) ◽  
pp. 1238-1242 ◽  
Author(s):  
Taketoshi Nakahara ◽  
Tamotsu Wasa
Keyword(s):  
Inductively Coupled Plasma ◽  
Detection Limits ◽  
Atomic Emission ◽  
Atomic Emission Spectrometry ◽  
Emission Spectrometry ◽  
Plasma Atomic Emission ◽  
Plasma Atomic Emission Spectrometry ◽  
Inductively Coupled ◽  
Prior Oxidation

A simple prior-oxidation procedure is described for the determination of low concentrations of iodine by inductively coupled plasma-atomic emission spectrometry (ICP-AES) in the ultraviolet and vacuum ultraviolet (VUV) regions of the spectrum. For measuring spectral lines in the VUV region, the monochromator and the enclosed external optical path between the ICP source and the entrance slit of the monochromator have both been purged with nitrogen to minimize oxygen absorption below 190 nm. Iodine atomic emission lines at 206.16 and 183.04 nm have been selected as the analytical lines. The ICP-AES intensity is enhanced by a factor of up to 50 by prior oxidation of the iodide to elemental iodine using several oxidizing additives, presumably because of increased sample-transport efficiency between the nebulizer and the plasma. The best attainable detection limits (3-σ criterion) for iodine at 183.04 and 206.16 nm were 2.00 and 13.9 ng/mL, respectively, in the presence of 3.5-M perchloric acid or 0.2-M hydrogen peroxide, while the corresponding detection limits were 0.088 and 0.56 μ/mL in the absence of an oxidizing additive. The typical analytical working graphs obtained under the optimized operating conditions were rectilinear over approximately five orders of magnitude in concentration.

Determination of nitrites and nitrates in drinking water using capillary electrophoresis

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Eva Martínková ◽  
Tomáš Křžek ◽  
Pavel Coufal
Keyword(s):  
Drinking Water ◽  
Rapid Determination ◽  
Background Electrolyte ◽  
Internal Standard ◽  
Detection Limits ◽  
Electrophoretic Method ◽  
Sample Stacking ◽  
Total Analysis ◽  
Drinking Water Samples

AbstractThis work was concerned with developing an electrophoretic method for rapid determination of nitrites and nitrates in drinking water. The background electrolyte was Tris-HCl buffer with an addition of cetyltrimethylammonium chloride to reverse the electro-osmotic flow. Online preconcentration of samples using the field-amplified sample stacking method provided detection limits of 0.003 mg L−1 (i.e. 65 nM) for nitrites and 0.010 mg L−1 (i.e. 160 nM) for nitrates, which are sufficiently low for quality control of drinking water. The method was tested in a concentration range corresponding to real drinking water samples and the differentiation between nitrites and nitrates was sufficient for simultaneous determination of nitrites at their concentrations of the order of tenths of mg L−1 and nitrates at their concentrations of the order of units to tens of mg L−1. A number of authors have neglected this important aspect when concentrating only on achieving the lowest possible detection limits. Separation of the two analytes and iodate as an internal standard was achieved in only three minutes. Total analysis time including preconditioning was eight minutes.

scholarly journals A Comparison of ETV and LA for the Determination of Trace Elements in Solid Samples by MIP OES

2019 ◽  
Vol 26 (3) ◽  
pp. 429-441
Author(s):  
Henryk Matusiewicz ◽  
Mariusz Ślachciński
Keyword(s):  
Trace Elements ◽  
Certified Reference Materials ◽  
Detection Limits ◽  
Optimization Procedure ◽  
Sample Introduction ◽  
Matrix Composition ◽  
Emission Spectrometry ◽  
Solid Samples ◽  
Mip Oes

Abstract The performance of electrothermal vaporization (ETV) and laser ablation (LA) of dry aerosols as sample introduction systems for microwave induced plasma optical emission spectrometry (MIP OES) are compared and evaluated in terms of detection limits, precision and accuracy for the determination of trace elements (Ca, Cd, Cu, Fe, Mg, Mn, Sr, Zn) in the same solid micro samples. In MIP OES both radiation sources can be independently adjusted to optimize the sampling process and then its subsequent excitation. A univariate approach and simplex optimization procedure were used to obtain the best signal/noise (S/N) ratio and derive analytical figures of merit. A comparison using a Student’s t-test between the results obtained by both ETV/LA-MIP OES methods for trace elements, and concentrations in standard reference material (SRM) and certified reference materials (CRMs) showed that there was no significant differences on a 95 % confidence level. The detection limits of the tested elements in solid samples by ETV/LA-MIP OES were in the range of 0.1 to 11 µg g−1 for all elements determined, while the corresponding absolute values in the range of ng. The precision of the results for ETV-MIP OES and LA-MIP OES varied between 2 and 4 % and 3 and 7 %, respectively. The linear dynamic ranges in the ETV/LA-MIP OES are extend over three decades of concentration. The methods were validated by the analysis of NIST SRM 2711Montana Soil, NRCC CRM PACS-2 Marine Sediment and NRCC CRM TORT-2 Lobster Hepatopancreas of different matrix composition and by the standard addition technique.

Determination of Aluminium in Serum, Dialysate Fluid and Water by Inductively Coupled Plasma Optical Emission Spectrometry

1995 ◽  
Vol 32 (2) ◽  
pp. 160-166 ◽  
Author(s):  
T D B Lyon ◽  
C Cunningham ◽  
D J Halls ◽  
J Gibbons ◽  
A Keating ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Matrix Effects ◽  
Internal Standard ◽  
Optical Emission ◽  
Optical Emission Spectrometry ◽  
Atomic Spectrometry ◽  
Emission Spectrometry ◽  
Inductively Coupled ◽  
Plasma Optical Emission Spectrometry

Methods for the determination of aluminium in serum, dialysate fluid and water by inductively coupled plasma optical emission spectrometry are described and validated. Aluminium was measured at 167 nm using an argon purged monochromator. Matrix effects in serum and dialysate fluid were overcome by using an yttrium internal standard. Serum was found to have a complicated background in the region of 167 nm: Careful selection of the wavelength used for background correction is therefore a pre-requisite for accurate analysis. The method for serum was validated by comparison with electrothermal atomization atomic spectrometry and the limit of agreement determined to be ±0·3 μmol/L. Routine performance in a quality assessment scheme has been highly satisfactory for a period of 1 year. The method is ideal for fast and accurate monitoring of patients potentially at risk from aluminium toxicity.

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