Quantification of manganese and mercury in toenail in vivo using portable X-ray fluorescence (XRF)

Abstract

Background and objective Toenail is an advantageous biomarker to assess exposure to metals such as manganese and mercury. Toenail Mn and Hg are in general analyzed by chemical methods such as inductively coupled plasma mass spectrometry and atomic absorption spectrophotometry. In this project, a practical and convenient technology—portable X-ray florescence (XRF)—is studied for the noninvasive in vivo quantification of manganese and mercury in toenail. Material and methods The portable XRF method has advantages in that it does not require toenail clipping and it can be done in 3 min, which will greatly benefit human studies involving the assessment of manganese and mercury exposures. This study mainly focused on the methodology development and validation which includes spectral analysis, system calibration, the effect of toenail thickness, and the detection limit of the system. Manganese- and mercury-doped toenail phantoms were made. Calibration lines were established for these measurements. Results The results show that the detection limit for manganese is 3.65 μg/g (ppm) and for mercury is 0.55 μg/g (ppm) using 1 mm thick nail phantoms with 10 mm soft tissue underneath. Discussion and conclusion We conclude that portable XRF is a valuable and sensitive technology to quantify toenail manganese and mercury in vivo.

Validation of x-ray fluorescence measurements of metals in toenail clippings against inductively coupled plasma mass spectrometry in a Nigerian population ,

“…An exponential background was included depending on the element being fit and the spectral features in that area. [23] For example, the Mn peak includes fitting for the Fe peak. Since the Fe peak is so large, it is a primary component of the background under the Mn alpha peak, and, thus, was used in the fitting to better distinguish the background counts.…”

Reprocessing Zamak laryngoscope blades into new instrument parts; an ‘all-in-one’ experimental study

“…To determine the purity of all of the casted ingots, they are compared with samples made from virgin Zamak 3. All of the cylindrical samples are analyzed using X-ray fluorescence (XRF) spectroscopy (Panalytical Axios Max WD-XRF, Malvern, United Kingdom) [31][32][33][34][35]. The purity is calculated with SuperQ5.0i/Omnian software.…”

The measurement of trace elements in human nails and nail clippings using portable X‐ray fluorescence: A review

“…As, Se Intact nail phantoms Detection limit depends on nail thickness, backing As Human nail clippings (single clippings) r = 0.77; r = 0.89 when using limited subset 2021 41 Mn, Pb Human nail clippings (clipping collections) Normalization introduced; r = 0.91 (Mn), r = 0.32 (Pb) 2018 42 Mn, Hg Intact nail phantoms Detection limit higher for Mn 2018 43 Intact nail phantoms Dosimetry: Experimental and simulation results 2019 44 F I G U R E 1 Energy spectrum obtained from portable X-ray fluorescence measurement of a single nail clipping. The red line represents the overall fit to the data, with contributions from various elements and the background continuum.…”

“…In vivo pXRF analysis, however, does result in a small dose of ionizing radiation for the person undergoing the procedure. 35,[43][44][45][46] This is likely to discourage some people from pursuing the in vivo measurement option, and may limit the extent to which the timedependent exposure information can be practically obtained. There is also an outstanding question as to whether any cleaning procedures applied to the intact nail (to remove possible external contamination) can be as effective as the robust cleaning protocols normally used when working with nail clippings.…”

“…The possibility of in vivo assessment of Mn and Hg in toenail has also been demonstrated through phantom measurements. 43 These recent examples point toward increasing applications of pXRF in population studies and, potentially, public health.…”