X-ray fluorescence spectral analysis of metals and alloys

Quantitative spectral analysis (determination of the concentration of a given set of elements)

Quantitative X-ray fluorescence analysis is characterized by high reproducibility of results provided that the sample is representative and very good sensitivity. The superior stability of today's instruments eliminates the need for repetitive measurements or frequent recalibrations. This guarantees high accuracy at low analysis costs. The quantitative analysis is based on the dependence of the intensity of characteristic radiation on the wavelength. The nature of this dependence is established experimentally on the basis of calibration, i.e. measuring the intensity (I) of characteristic fluorescence in several standard (reference) samples - samples with a precisely known concentration (C) of the element to be determined. Conversion of the measured intensities of elements of an unknown sample into concentration units is based on the performed calibration, which is described mathematically using a calibration function. For example: I = aC + b. When processing the measurement results, the task of the calibration function is to answer the question: "What is the concentration of an element in the sample, at which fluorescent radiation of the measured intensity appears?"

The result of quantitative X-ray fluorescence analysis is the value of the concentration of an element in the sample, which can be expressed in%, ppm (g / t), g / kg, mg / L or other units derived from concentration. For silicate rocks, the concentration is usually represented as a% of element oxides.

Qualitative spectral analysis (finding the elements that make up the sample)

The basis of a qualitative spectral analysis is the presence or absence of lines of characteristic radiation of an element in the spectrum of a sample. An element is considered to be present in a sample when at least two lines of its characteristic radiation are found in the spectrum. Element line detection is carried out by finding the wavelengths of the spectrum peaks and searching the found values in a database of X-ray lines. This operation is carried out by a computer.

The result of a qualitative analysis looks like a list of elements clearly present in the sample and elements present in the sample in very small (trace) quantities.

Semi-quantitative spectral analysis (rapid determination of the qualitative and quantitative composition of the sample)

Semi-quantitative spectral analysis is carried out in the case of an unknown substance, when in a very short time it is required to find out the approximate concentrations of all the elements present in the sample. This type of analysis is useful for planning further studies of a substance, as well as in cases where the elements present in the sample cannot be analyzed quantitatively due to very high or very low concentrations, which were not envisaged when the quantitative analysis method was developed. The lack of standard samples for the quantitative analysis of rare elements also becomes the reason for the semi-quantitative analysis.

The result of a semi-quantitative analysis is the approximate values of the concentrations of ALL elements.

Substance identification (comparison of an unknown substance with a standard)

This type of analysis is carried out when it is necessary to identify the composition and some physical properties of two samples, one of which is a reference. This type of analysis is important when looking for any difference in the composition of two samples. In X-ray fluorescence spectrometry, it is possible to carry out a detailed comparison of samples not only by the characteristic spectra of the elements, but also by the intensity of the background (bremsstrahlung) radiation and by the shape of the Comptan scattering bands. This takes on special meaning when the chemical composition of two samples is the same according to the results of quantitative analysis, but the samples differ in other properties, such as grain size, crystallite size, surface roughness, porosity, moisture, the presence of crystallization water, polishing quality, spray thickness, etc. Identification is carried out on the basis of a detailed comparison of the spectra. In this case, there is no need to know the chemical composition of the sample. Any difference between the compared spectra is irrefutable evidence that the sample under study differs from the standard.

The result of this type of research is confirmation or denial of the identity of two samples.

Analysis of individual elements

Quantitative spectral analysis of a limited number of elements in large batches of samples. The set of analyzed elements is determined by the customer.

Equipment and devices

An X-ray fluorescent spectral analyzer manufactured by Elvatech LLC is used for the analysis. The device is designed for express, qualitative and quantitative analysis of the composition of metal alloys, powders, liquids, deposits on filter elements, biological samples, food for the content of chemical elements from Na (atomic number Z = 11) to U (Z = 92) in a wide range of concentrations ...

The ElvaX portable X-ray fluorescence analyzer represents a new generation of analytical equipment for high-precision analysis of the elemental composition of substances. ElvaX is a benchtop energy dispersive X-ray fluorescence spectrometer that does not require liquid nitrogen for operation and storage. The use of the spectrometer allows for prompt non-destructive elemental analysis of raw materials and products of arbitrary shape without preliminary sample preparation at all stages of the production cycle or laboratory research. The spectrometer is entered in the State Register of Measuring Instruments, approved for use in Ukraine, under the number U1411-01. Type approval certificate for measuring instruments No. UA-MI / 1-971-2001.

The results obtained by the method of X-ray fluorescence spectrometry (XRF, XRF) meet the requirements of the III category of analysis accuracy according to OST 41-08-205-99. This category is used for mass analysis of geological samples during exploration work, reserves calculation and for control analyzes.

In world practice, X-ray fluorescence analysis has become one of the main methods for studying geological samples, mining products and mineral materials, modern equipment allows obtaining high-precision results.

We invite you to use the analytical service, which provides a reliable high-performance analysis of the chemical composition of mineral substances and materials: rocks, ores and products of their processing, concentrates, tailings, slags, products made of inorganic materials, production waste, environmental objects, etc.