# US 12,007,380 B2 · Apparatus and method for x-ray fluorescence analysis

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- Number: US 12,007,380 B2
- Document ID: US12007380B2
- Status: Granted
- Kind: B2
- Application number: 17/743,930
- Filed: 2022-05-13
- Published: 2022-11-17
- Granted: 2024-06-11
- Earliest claimed: 2021-05-14
- Assignees: Malvern Panalytical Limited
- Applicants: Malvern Panalytical B.V.
- Inventors: Bruno Vrebos; Lieven Kempenaers; Youhong Xiao
- Web page: https://patentgrep.com/patent/US12007380B2

## CPC

- G01N 33/26: Oils; Viscous liquids; Paints; Inks (G01N33/22 takes precedence)
- G01N 33/287: {Sulfur content}
- G01N 23/223: by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence
- G01N 2223/076: X-ray fluorescence
- G01N 2223/1016: X-ray
- G01N 2223/204: source created from radiated target
- G01N 2223/303: calibrating, standardising
- G01N 2223/313: filters, rotating filter disc
- G01N 2223/637: liquid
- G01N 2223/652: impurities, foreign matter, trace amounts
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

This application relates to apparatus and method for x-ray fluorescence analysis. There is provided an X-ray fluorescence analysis apparatus for analysing a sample, The X-ray fluorescence analysis apparatus comprises an X-ray source, a measurement chamber for holding the sample in air, and an X-ray detector. The X-ray source is arranged to irradiate the sample with a primary X-ray beam, to cause the sample to fluoresce. The X-ray detector is arranged to detect characteristic X-rays emitted by the sample and to determine a measured X-ray intensity associated with the characteristic X-rays. An X-ray filter, which transmits the primary X-ray beam, is arranged between the X-ray source and the sample. The X-ray source comprises an anode of material having an atomic number that is less than 25. The X-ray fluorescence analysis apparatus further comprises a sensor arrangement configured to sense air pressure and air temperature. A processor receives the measured X-ray intensity. The processor also receives air pressure data and air temperature data from the sensor arrangement. The processor is configured to carry out a compensation calculation for adjusting the measured X-ray intensity using the air pressure data and the air temperature data.

## Claims

### Claim 1

An X-ray fluorescence analysis apparatus for analysing a sample, the X-ray fluorescence analysis apparatus comprising:
a measurement chamber for holding the sample in an air atmosphere;
an X-ray source arranged to irradiate the sample with a primary X-ray beam, the X-ray source comprising an anode comprising material having an atomic number that is less than 25;
an X-ray filter arranged between the X-ray source and the sample, wherein the X-ray filter is configured to transmit the primary X-ray beam and to attenuate at least some X-rays having energies between 2 keV and 3 keV, wherein the X-ray filter has an attenuation of greater than 95% at an X-ray energy of greater than 2 keV and less than 3 keV, or wherein the filter has an attenuation of greater than 95% at an energy range of between 2.0 keV and 2.9 keV;
an X-ray detector arranged to detect X-rays emitted by the sample, wherein the X-ray detector is configured to determine a measured X-ray intensity and a measured X-ray energy;
a sensor arrangement configured to measure air pressure and air temperature; and
a processor configured to:
receive the measured X-ray intensity;
receive an air pressure measurement and an air temperature measurement from the sensor arrangement; and
carry out a compensation calculation for adjusting the measured X-ray intensity using the air pressure measurement and the air temperature measurement.

### Claim 2 (depends on 1)

The X-ray fluorescence analysis apparatus of claim 1 wherein the compensation calculation comprises calculating a correction factor that represents the effect of the air pressure and the air temperature, at the time of measurement, on the measured X-ray intensity.

### Claim 3 (depends on 1)

The X-ray fluorescence analysis apparatus of claim 1 wherein the X-ray detector is configured to determine a plurality of X-ray intensities, each X-ray intensity corresponding to a different X-ray energy, and the processor is configured to calculate a plurality of corresponding correction factors, wherein each correction factor represents the effect of the air pressure and the air temperature, at the time of measurement, on the measured X-ray intensity.

### Claim 4 (depends on 1)

The X-ray fluorescence analysis apparatus of claim 1, wherein the X-ray source comprises an X-ray tube that is configured to operate at an X-ray tube power of equal to or less than 20 W.

### Claim 5 (depends on 1)

The X-ray fluorescence analysis apparatus of claim 1, wherein the X-ray filter comprises a filter element for attenuating X-rays, the filter element comprising aluminium and having a thickness of between 10 μm and 25 μm.

### Claim 6 (depends on 1)

The X-ray fluorescence analysis apparatus of claim 1, wherein the anode comprises vanadium, chromium, titanium or scandium.

### Claim 7 (depends on 5)

The X-ray fluorescence analysis apparatus of claim 5 wherein the X-ray source comprises a vanadium anode.

### Claim 8 (depends on 1)

The X-ray fluorescence analysis apparatus of claim 1, wherein the X-ray detector is an energy dispersive X-ray detector.

### Claim 9 (depends on 1)

The X-ray fluorescence analysis apparatus of claim 1, further comprising a housing, wherein the X-ray source, the measurement chamber, the X-ray detector and the X-ray filter are contained inside the housing.

### Claim 10

A method of carrying out X-ray fluorescence analysis on a sample comprising:
holding the sample in a measurement chamber, in an air atmosphere;
generating a primary X-ray beam, from an anode comprising a material having an atomic number of less than 25, and irradiating the sample with the primary X-ray beam;
using an X-ray filter to attenuate at least some X-rays from the anode having an energy between 2 keV and 3 keV, wherein the X-ray filter has an attenuation of greater than 95% at an X-ray energy of greater than 2 keV and less than 3 keV, or wherein the filter has an attenuation of greater than 95% at an energy range of between 2.0 keV and 2.9 keV;
sensing an ambient air pressure and an ambient air temperature;
detecting X-rays emitted by the sample; and
carrying out a compensation calculation for adjusting the measured X-ray intensity using the air pressure measurement and the air temperature measurement.

### Claim 11 (depends on 10)

The method of claim 10 wherein the X-ray source comprises an X-ray tube and the X-rays are generated by operating the X-ray tube at an X-ray tube power of less than 20 W.

### Claim 12 (depends on 10)

The method of claim 10 wherein the compensation calculation comprises calculating a correction factor that represents the effect of the air pressure and the air temperature, at the time of measurement, on the measured X-ray intensity.

### Claim 13 (depends on 10)

The method of claim 10, wherein the sample comprises petroleum, a petroleum product or a biofuel and/or wherein the sample comprises an analyte having an atomic number that is equal to or less than 17.