Technology – Monochromatic Wavelength Dispersive X-ray Fluorescence (MWD XRF)

The Sindie sulfur analyzer is used to determine the total sulfur in gasoline, diesel fuels, and other petroleum products. The analyzer employs a method based on focused monochromatic excitation wavelength-dispersive X-ray fluorescence (MWDXRF) spectrometry to measure sulfur content. The Sindie MWDXRF analyzer engine configuration is below.

The Sindie technique employs a low-power X-ray tube, a point-focusing doubly-curved crystal (DCC) optic for excitation, a sample cell, a second focusing DCC optic for collection, and an X-ray detector. The first point focusing optic captures a narrow bandwidth of X-rays from the source and focuses this intense monochromatic beam to a small spot on the fuel sample cell. The monochromatic beam excites the sample and secondary characteristic fluorescence X-rays are emitted. The second collection optic collects only the characteristic sulfur X-rays emitted from the small spot sample and focuses them onto the detector.This configuration offers several advantages over conventional WDXRF systems. The signal-to-background is improved by using the monochromatic excitation of the X-ray source characteristic line. The focusing ability of the collection optic allows using a small-area X-ray counter detector which results in low detector noise and enhanced reliability. Monochromatic excitation also provides simplified quantification and matrix effect correction. This technique enables robust low-maintenance analyzers with dramatically lower detection limits and faster response times.

For a general technology overview of X-ray fluorescence spectroscopy please see this link.