A Laboratory‐Based Sequential Scanning X‐Ray Emission Spectroscopy Instrument and Its Performance in Identifying Chromium Speciation

ABSTRACT To tackle the deficiency of traditional energy‐dispersive X‐ray fluorescence (EDXRF) in resolution, we have innovatively proposed, designed, and developed a laboratory‐based dual‐dispersion, dual‐focusing, and sequential scanning X‐ray emission spectroscopy (XES) instrument. Experimental outcomes reveal that this XES instrument showcases prominent features. In terms of resolution, it surges from the 121 eV of traditional EDXRF to 45 eV, marking a 3.1‐fold enhancement. When it comes to the peak‐to‐background ratio, compared with traditional EDXRF, for Chromium (Cr), Manganese (Mn), and Iron (Fe), it has been improved by 12–195 times, 12–195 times, and 5.7–7.8 times, respectively. Notably, the XES instrument exhibits extremely low background and high sensitivity. The linear correlation coefficient of Chromium (Cr) concentration and characteristic peak intensity climbs from 0.394 to 0.896, and the residual sum of squares for I‐Wt. (intensity‐weight) drops from 5.28 × 10 6 to 6.20 × 10 2 , greatly boosting the concentration–intensity correlation and analytical accuracy. Moreover, this XES instrument successfully achieves spectral separation of Cr(0), Cr(III), and Cr(VI), laying a solid groundwork for chromium speciation analysis in environmental samples. Overall, this development represents a significant stride in advancing X‐ray spectroscopy for both elemental analysis and speciation studies, with promising implications for a wide array of scientific and practical applications.