ABSTRACT Total reflection X‐ray fluorescence (TXRF) analysis is widely used for determining the concentrations of trace elements in various solutions. This technique offers several advantages, notably low required sample volume, simple sample preparation, and high sensitivity. Furthermore, the emergence of commercially available portable type TXRF instruments has opened the door to on‐site analysis. To achieve a compact design, these instruments commonly incorporate a waveguide to collimate the continuous X‐rays. Since its intensity is proportional to the atomic number of the X‐ray tube target, W is generally used. However, characteristic X‐rays originating from W often overlap with XRF peaks of target elements such as Zn. Therefore, to enable comprehensive on‐site analysis of all elements, we developed a primary X‐ray filter using 3D printing technique. The 3D‐printed frame is robust, and its preparation cost is significantly low. We applied this method to Zn analysis. By using a 3D‐printed filter with Ni film, the overlap of W Lα and Zn Kα peaks was successfully resolved. This demonstrates its utility in inhibiting the peak interference from W. A key advantage of the 3D‐printed filter is the simplicity of deinstallation. This feature allows the 3D‐printed filter to be easily removed when analyzing target elements such as Cr, that exhibit no interference from W peaks. Thus, this technique enables high sensitivity TXRF analysis for virtually all metal elements.
Matsuyama et al. (2026) studied this question.