Peter J. Cumpson. “On-site trace heavy-metal detection at surfaces by handheld X-ray fluorescence.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15007927/v1

Values presented only in spectra or other plots or images were not transcribed. Routine-analysis comparisons and method-performance results were not retained. No separate supporting information file was available on the ChemRxiv article page

Mercury-containing reference film on platinum
XRF The film contained 20.5 µg cm⁻² Hg and 14.7 µg cm⁻² Ag deposited on a 3.5 µm polyester membrane
Differential XRF, normalized to the Pt Lα1 peak Hg Lα1 and Hg Lβ1 peaks were observed at 9.99 and 11.82 keV, respectively
Main, pp. 8–9
Freshly scraped platinum reference foil
Differential XRF, normalized to the Pt Lα1 peak No mercury peaks were observed
Main, pp. 8, 10
RS1 platinum troy-pound mass standard
Differential XRF, five platinum-reference and four RS1 spectra acquired in the order ABABABABA, 60 s per spectrum, normalized to the Pt Lα1 peak Hg Lα1 and Hg Lβ1 peaks were observed at 9.99 and 11.82 keV, respectively; the mercury areal density was 0.96 µg cm⁻² with an estimated uncertainty of approximately ±20 %