{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T18:04:02Z","timestamp":1774289042221,"version":"3.50.1"},"reference-count":33,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2023,1,2]],"date-time":"2023-01-02T00:00:00Z","timestamp":1672617600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/04035\/2020"],"award-info":[{"award-number":["UIDB\/04035\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/FIS\/04559\/2020"],"award-info":[{"award-number":["UID\/FIS\/04559\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Eng"],"abstract":"<jats:p>Micrometric 2D mapping of distinct elements was performed in distinct soil grain-size fractions of a sample using the micro-X-ray Fluorescence (\u00b5-XRF) technique. The sample was collected in the vicinity of S\u00e3o Domingos, an old mine of massive sulphide minerals located in the Portuguese Iberian Pyrite Belt. As expected, elemental high-grade concentrations of distinct metals and metalloids in the dependence of the existent natural geochemical anomaly were detected. Clustering and k-means statistical analysis were developed considering Red\u2013Green\u2013Blue (RGB) pixel proportions in the produced 2D micrometric image maps, allowing for the identification of elemental spatial distributions at 2D. The results evidence how elemental composition varies significantly at the micrometric scale per grain-size class, and how chemical elements present irregular spatial distributions in the direct dependence of distinct mineral spatial distributions. Due to this fact, elemental composition is more differentiated in coarser grain-size classes, whereas griding-milled fraction does not always represent the average of all partial grain-size fractions. Despite the complexity of the performed analysis, the achieved results evidence the suitability of \u00b5-XRF to characterize natural, heterogeneous, granular soils samples at the micrometric scale, being a very promising investigation technique of high resolution.<\/jats:p>","DOI":"10.3390\/eng4010008","type":"journal-article","created":{"date-parts":[[2023,1,3]],"date-time":"2023-01-03T02:51:39Z","timestamp":1672714299000},"page":"136-150","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Investigating Metals and Metalloids in Soil at Micrometric Scale Using \u00b5-XRF Spectroscopy\u2014A Case Study"],"prefix":"10.3390","volume":"4","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6233-2970","authenticated-orcid":false,"given":"Sofia","family":"Barbosa","sequence":"first","affiliation":[{"name":"GeoBioTec GeoBioSciences, GeoTechnologies and GeoEngineering & NOVA FCT (Department of Earth Sciences), Faculdade de Ci\u00eancias e Tecnologia, 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3197-9146","authenticated-orcid":false,"given":"Ant\u00f3nio","family":"Dias","sequence":"additional","affiliation":[{"name":"LIBPhys & NOVA FCT (Department of Physics), 2829-516 Caparica, Portugal"}]},{"given":"Marta","family":"Pacheco","sequence":"additional","affiliation":[{"name":"NOVA FCT (Department of Earth Sciences), 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6039-2494","authenticated-orcid":false,"given":"Sofia","family":"Pessanha","sequence":"additional","affiliation":[{"name":"LIBPhys & NOVA FCT (Department of Physics), 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7021-0113","authenticated-orcid":false,"given":"J. Ant\u00f3nio","family":"Almeida","sequence":"additional","affiliation":[{"name":"GeoBioTec GeoBioSciences, GeoTechnologies and GeoEngineering & NOVA FCT (Department of Earth Sciences), Faculdade de Ci\u00eancias e Tecnologia, 2829-516 Caparica, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1140\/epjp\/s13360-021-01422-y","article-title":"Elemental mapping of Portuguese ceramic pieces with a full-field XRF scanner based on a 2D-THCOBRA detector","volume":"136","author":"Carvalho","year":"2021","journal-title":"Eur. Phys. J. Plus"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"923","DOI":"10.1180\/minmag.2016.080.150","article-title":"Application of benchtop micro-XRF to geological materials","volume":"81","author":"Flude","year":"2017","journal-title":"Mineral. 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