Mercury-free concentration standard for x-ray analysis

Patent metadata

Field	Value
Publication number	US-10871583-B2
Application number	US-201916387596-A
Country	US
Kind code	B2
Filing date	Apr 18, 2019
Priority date	Apr 24, 2018
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

Instruments used to analyze the chemical composition of samples must be calibrated to provide accurate results. Typically, standards are prepared that contain a known amount of the intended analyte to facilitate calibration of the analytical instrument. Various environmental issues are associated with use of mercury containing materials as standards for calibration of analytical instruments. Mercury and gold have very similar characteristic X-ray energies. Standards containing gold nanoparticles have been found to be a good surrogate for mercury in X-ray spectroscopy.

First claim

I claim:

1. A standard without the toxicity of mercury used to calibrate an apparatus used to analyze a sample for mercury content which comprises:
(a) gold nanoparticles;
(b) a matrix powder.

2. The standard of claim 1 wherein the apparatus is a spectrophotometer.

3. The standard of claim 1 wherein the matrix powder is copper.

4. The standard of claim 1 wherein the matrix powder is tin.

5. The standard of claim 1 wherein the matrix powder is silver.

6. The standard of claim 1 where the elemental matrix powder forms a solid incorporating the gold nanoparticles on compression.

7. The standard of claim 1 where the matrix powder is comprised of more than one element.

8. The standard of claim 1 wherein the matrix powder is bound together by a precisely defined quantity of binder.

9. A method for determining the concentration of mercury in a sample comprising:
(a) calibrating an X-ray spectrometer using a standard,
(b) analyzing the sample using the calibrated X-ray spectrometer,
(c) wherein the standard is comprised of gold nanoparticles and a matrix powder.

10. The method of claim 9 wherein the matrix powder is copper.

11. The method of claim 9 wherein the matrix powder is tin.

12. The method of claim 9 wherein the matrix powder is silver.

Assignees

• Univ Louisiana At Lafayette

Inventors

• Whitlow Harry James

Classifications

• G01T7/005 Primary

  calibration techniques (stabilization of spectrometer G01T1/40) · CPC title

• G01N23/207

  Diffractometry using detectors, e.g. using a probe in a central position and one or more displaceable detectors in circumferential positions · CPC title

• G01N23/223 Primary

  by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence · CPC title