Differential surface composition analysis by multiple-voltage electron beam X-ray spectroscopy
AssigneeThe United States of America as represented by the Department of Health and Human Services
InventorsWilliam E. Wallace, Michael J. Keane
Life of this patent
Estimating the term…
Abstract
A method of differential surface composition analysis which allows non-destructive compositional analysis with depths below a solid surface is used to analyze respirable dust particles to determine the presence of hazardous components in the surface of the dust particles. A method of incubating respirable particles in a surrogate pulmonary surfactant system used in combination with the differential surface composition analysis allows determination of surface components which survive or are exposed on the respiratory particles after incubation in the surrogate pulmonary surfactant, representing modification of the partical surface upon deposition in the lung.
Claims18
A method of differential surface compositional analysis which comprises:
- subjecting a solid material to electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to a first kinetic energy sufficient to analyze material at a first depth below the surface of said solid material without causing surface damage to said solid material;
- measuring elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said first kinetic energy;
- subjecting said solid material to electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to a second kinetic energy sufficient to analyze material at a second depth below the surface of said solid material without causing surface damage to said solid material;
- measuring elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said second kinetic energy;
- and
- comparing said measured elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said first and second kinetic energies to determine the differential surface composition of said solid material.
A method of analyzing the composition of solid particles which comprises:
- subjecting a solid particle to electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to a first kinetic energy sufficient to analyze material at a first depth below the surface of said solid particle without causing surface damage to said solid particle;
- measuring elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said first kinetic energy;
- subjecting said solid particle to electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to a second kinetic energy sufficient to analyze material at a second depth below the surface of said solid particle without causing surface damage to said solid particle;
- measuring elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said second kinetic energy;
- and
- comparing said measured elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said first and second kinetic energies to determine the differential surface composition of said solid particle.
A method of identifying respirable particles which may be pathogenic in a lung, which method comprises:
- incubating respirable particles in a surrogate pulmonary surfactant;
- and
- subjecting said particles to differential surface compositional analysis to determine the surface composition of said particles, wherein said differential surface compositional analysis comprises:
- subjecting respirable particles to electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to a first kinetic energy sufficient to analyze material at a first depth below the surface of said solid particle without causing surface damage to said solid particle;
- measuring elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said first kinetic energy;
- subjecting said solid particle to electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to a second kinetic energy sufficient to analyze material at a second depth below the surface of said solid particle without causing surface damage to said solid particle;
- measuring elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said second kinetic energy;
- and
- comparing said measured elemental X-ray signals caused by said electron beam-induced X-ray spectroscopic analysis with the electron beam accelerated to said first and second kinetic energies to determine the differential surface composition of said solid particle.
Dependencies are inferred from the claim text.