Micro X-ray fluorescence (µXRF) is an elemental analysis technique that allows the detection of very small sample areas (typically tens to hundreds of micrometers in diameter) using monochromatic radiation. X-ray optical crystals can capture X-rays from a source with a large angular divergence and redirect them to form a strongly focused beam on the sample surface, thereby enhancing µXRF applications. Monochromatic µXRF (or MµXRF) employs doubly curved crystal optics that direct a high-intensity, micrometer-sized monochromatic X-ray beam onto the sample surface for enhanced elemental analysis. Compared with µXRF techniques, MµXRF using polychromatic excitation offers numerous advantages in certain applications, including longer working distances and easier quantitative analysis. More importantly, monochromatic excitation eliminates the X-ray scattering background beneath fluorescence peaks, thus providing very high sensitivity. With this technique, typical detection limits of ppb levels (for bulk contaminants) or femtogram levels can be achieved.

MµXRF technology can be implemented in both EDXRF and WDXRF configurations with built-in DCC crystal optics.


Monochromatic WDXRF using doubly curved crystal optics offers very high sensitivity for specific sample elements of interest. This technique has been successfully applied to the determination of low sulfur content in petroleum products.