What is X-ray fluorescence (XRF) primarily used for?

• A. A destructive testing method used to determine mechanical properties.
• B. A method for imaging soft tissues.
• C. A process for separating elements by chemical properties.
• D. A diagnostic, non-destructive testing technique that can detect and measure the concentration of elements in substances.

Answer: (D)

X-ray fluorescence is a diagnostic, non-destructive technique that can detect and measure the concentration of elements in substances. When a material is irradiated with X-rays, its atoms emit characteristic X-rays that reveal which elements are present and, with proper calibration, how much of each element is there. This makes XRF ideal for quickly and non-destructively determining elemental composition in metals and alloys, rocks and soils, plastics, art and archaeological samples, and for field analysis with portable devices. The other descriptions describe destructive testing of mechanical properties, medical imaging of soft tissues, or chemical separation processes, none of which match what XRF does.