Visible-light photoreduction, adsorption, matrix conversion and membrane separation for ultrasensitive chromium determination in natural water by X-ray fluorescence

- A novel sample pretreatment method for portable detection technology, e.g., XRF.
- Phototransformation, enrichment, separation, and matrix conversion are co-used.
- Major obstacles on linear range, matrix effects and sensitivity are overcome.
- Detection limit of XRF is improved from 2 mg L−1 to 0.59 μg L−1, close to ICP-MS.