{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T21:04:14Z","timestamp":1792789454436,"version":"4.5.0"},"reference-count":35,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T00:00:00Z","timestamp":1791417600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T00:00:00Z","timestamp":1791417600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Polish Ministry of Science and Higher Education","id":[{"id":"https:\/\/ror.org\/05dwvd537","id-type":"ROR","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/05dwvd537","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Foods"],"abstract":"<jats:p>In this research, an accurate procedure was developed to determine Cd, Cu, Pb and Si in dietary supplements using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). The operational parameters for the graphite furnace method were thoroughly investigated, including the influence of the chemical modifier along with the optimisation of pyrolysis and atomisation temperatures. The detection limits for Cd, Cu, Pb, and Si were 0.02 \u00b5g L\u22121, 0.35 \u00b5g L\u22121, 0.18 \u00b5g L \u22121 and 0.98 \u00b5g L \u22121, respectively. The accuracy of the method was validated using INCT-MP4-2 (Mixed Polish Herbs) as a certified reference material and complemented by standard addition tests. The determined elemental contents showed satisfactory agreement with both certified values and the spiked amounts, as confirmed by a t-test at 95% confidence level. The validated procedure was successfully applied to nine commercial dietary supplements representing three botanical silicon sources (bamboo, horsetail, and nettle). The analysis revealed a cadmium concentration in one horsetail-based sample (H1) that marginally exceeded the EU regulatory limit, as well as a substantial discrepancy between the declared and measured silicon content in another horsetail-based sample (H2), where the determined value was nearly eight times lower than stated by the manufacturer.<\/jats:p>","DOI":"10.3390\/foods15193577","type":"journal-article","created":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T15:16:52Z","timestamp":1791472612000},"page":"3577","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Determination of Cadmium, Copper, Lead, and Silicon in Anti-Hair Loss Dietary Supplements That Contain Various Plant-Derived Silicon Sources"],"prefix":"10.3390","volume":"15","author":[{"given":"Magdalena","family":"Krawczyk-Coda","sequence":"first","affiliation":[{"name":"Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, 60-965 Pozna\u0144, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,10,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1016\/j.ijwd.2018.05.001","article-title":"Female pattern hair loss: A clinical, pathophysiologic, and therapeutic review","volume":"4","author":"Fabbrocini","year":"2018","journal-title":"Int. J. Womens Dermatol."},{"key":"ref_2","first-page":"118","article-title":"Systematic Review: Causes and Treatments of Hair Loss","volume":"18","author":"Sankhwar","year":"2025","journal-title":"J. Derm. Case Rep."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1590\/abd1806-4841.20163986","article-title":"Use of Silicon for skin and hair care: An approach of chemical forms available and efficacy","volume":"91","author":"Addor","year":"2016","journal-title":"An. Bras. Dermatol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Al-Fawaeir, S., and Al-Odat, I. (2025). Quantitative Analysis of Selected Circulating Hematological Biomarkers, Essential Minerals, Vitamins, and Thyroid Hormones in Females Affected by Hair Loss. Diseases, 13.","DOI":"10.3390\/diseases13110352"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"41570","DOI":"10.1155\/2015\/841570","article-title":"A 3-month, randomized, double-blind, placebo-controlled study evaluating the ability of an extra-strength marine protein supplement to promote hair growth and decrease shedding in women with self-perceived thinning hair","volume":"2015","author":"Ablon","year":"2015","journal-title":"Dermatol. Res. Pract."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Jasi\u0144ska-Balwierz, A., Krypel, P., \u015awis\u0142owski, P., Rajfur, M., Balwierz, R., and Och\u0119dzan-Siod\u0142ak, W. (2025). Heavy Metal Contamination in Adaptogenic Herbal Dietary Supplements: Experimental, Assessment and Regulatory Safety Perspectives. Biology, 14.","DOI":"10.3390\/biology14111479"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Durazzo, A., Sorkin, B.C., Lucarini, M., Gusev, P.A., Kuszak, A.J., Crawford, C., Boyd, C., Deuster, P.A., Saldanha, L.G., and Gurley, B.J. (2022). Analytical Challenges and Metrological Approaches to Ensuring Dietary Supplement Quality: International Perspectives. Front. Pharmacol., 12.","DOI":"10.3389\/fphar.2021.714434"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1062","DOI":"10.5740\/jaoacint.16-0398","article-title":"Solid Phase Extraction Preconcentration Method for Simultaneous Determination of Cadmium, Lead, and Nickel in Poultry Supplements","volume":"100","author":"Baig","year":"2017","journal-title":"J. AOAC Int."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.foodchem.2016.09.121","article-title":"Determination of essential elements in beverages, herbal infusions and dietary supplements using a new straightforward sequential approach based on flame atomic absorption spectrometry","volume":"219","author":"Gismera","year":"2017","journal-title":"Food Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1016\/j.jpba.2013.09.016","article-title":"Determination of macro and trace elements in multivitamin dietary supplements by high-resolution continuum source graphite furnace atomic absorption spectrometry with slurry sampling","volume":"88","author":"Krawczyk","year":"2014","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.sab.2016.04.002","article-title":"Spectral aspects of the determination of Si in organic and aqueous solutions using high-resolution continuum source or line source flame atomic absorption spectrometry","volume":"120","author":"Kowalewska","year":"2016","journal-title":"Spectrochim. Acta Part B"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Ma\u0107kiewicz, E., Klimaszewska, M., Albi\u0144ska, J., and Szynkowska-J\u00f3\u017awik, M.I. (2025). Evaluation of the Elemental Composition of Dietary Supplements Containing Iron Available on the Polish Market Using ICP-OES, FAAS and CVAAS Techniques. Molecules, 30.","DOI":"10.3390\/molecules30234511"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Al-Thani, G., Ibrahim, A.E., Alomairi, M., Salman, B.I., Hegazy, M.M., Al-Harrasi, A., and El Deeb, S. (2023). Toxic Elemental Impurities in Herbal Weight Loss Supplements; A Study Using ICP-OES Microwave-Assisted Digestion. Toxics, 11.","DOI":"10.3390\/toxics11030272"},{"key":"ref_14","first-page":"50695","article-title":"Determination of Essential and Toxic Elements by ICP\u2013MS in Herbal Medicines","volume":"10","author":"Naozuka","year":"2025","journal-title":"ACS Omega"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"106401","DOI":"10.1016\/j.jfca.2024.106401","article-title":"Optimization and validation of a simple extraction method coupled with ICP-MS for the determination of essential and toxic elements in liquid dietary supplement products","volume":"133","author":"Elgammal","year":"2024","journal-title":"J. Food Compos. Anal."},{"key":"ref_16","first-page":"143","article-title":"Final Certification of Two New Reference Materials for Inorganic Trace Analysis","volume":"49","author":"Danko","year":"2004","journal-title":"Chem. Anal."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1016\/j.microc.2015.09.017","article-title":"Determination of silicon in plant materials using direct solid sample analysis with high-resolution continuum source graphite furnace atomic absorption spectrometry","volume":"124","author":"Boschetti","year":"2016","journal-title":"Microchem. J."},{"key":"ref_18","unstructured":"Meyers, R.A. (2006). Flame and Graphite Furnace Atomic Absorption Spectrometry in Environmental Analysis. Encyclopedia of Analytical Chemistry, John Wiley & Sons, Ltd."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1080\/05704928.2022.2147537","article-title":"The use of chemical modifiers in electrothermal atomic absorption spectrometry","volume":"59","author":"Acar","year":"2024","journal-title":"Appl. Spectrosc. Rev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1835","DOI":"10.1016\/S0584-8547(02)00140-4","article-title":"Modifiers and coatings in graphite furnace atomic absorption spectrometry\u2014Mechanisms of action (A tutorial review)","volume":"57","author":"Ortner","year":"2002","journal-title":"Spectrochim. Acta Part B"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1699","DOI":"10.1351\/pac199567101699","article-title":"Nomenclature in evaluation of analytical methods including detection and quantification capabilities (IUPAC Recommendations 1995)","volume":"67","author":"Currie","year":"1995","journal-title":"Pure Appl. Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1080\/00032719.2021.1918702","article-title":"Elemental Analysis of Pharmaceutical Products for Chronic Kidney Disease by High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry (HR\u2013CS GFAAS)","volume":"55","author":"Maziero","year":"2022","journal-title":"Anal. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2089","DOI":"10.1080\/00032719.2013.784918","article-title":"Determination of Cd, Cu, Ni, and Pb in Black Tea from Saudi Arabia using Graphite Furnace Atomic Absorption Spectrometry after Microwave-Assisted Acid Digestion","volume":"46","author":"Shaltout","year":"2013","journal-title":"Anal. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1746","DOI":"10.1007\/s12161-020-01787-3","article-title":"Sequential and simultaneous determination of chlorine, iron, and silicon in beer samples by high-resolution continuum source graphite furnace molecular and atomic absorption spectrometry","volume":"13","author":"Pires","year":"2020","journal-title":"Food Anal. Methods"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/j.talanta.2015.09.067","article-title":"Determination of silicon and aluminum in silicon carbide nanocrystals by high-resolution continuum source graphite furnace atomic absorption spectrometry","volume":"147","author":"Dravecz","year":"2016","journal-title":"Talanta"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"116553","DOI":"10.1016\/j.trac.2022.116553","article-title":"AGREEprep\u2014Analytical greenness metric for sample preparation","volume":"149","author":"Wojnowski","year":"2022","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"El-Beltagi, H.S., Sofy, M.R., Aldaej, M.I., and Mohamed, H.I. (2020). Silicon Alleviates Copper Toxicity in Flax Plants by Up-Regulating Antioxidant Defense and Secondary Metabolites and Decreasing Oxidative Damage. Sustainability, 12.","DOI":"10.3390\/su12114732"},{"key":"ref_28","first-page":"16479","article-title":"Relative absorption of silicon from different formulations of dietary supplements: A pilot randomized, double-blind, crossover post-prandial study","volume":"13","author":"Valls","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_29","unstructured":"European Commission (2021). Commission Regulation (EU) 2021\/1323 of 10 August 2021 amending Regulation (EC) No 1881\/2006 as regards maximum levels of cadmium in certain foodstuffs. Off. J. Eur. Union, L288, 13\u201318. Available online: https:\/\/eur-lex.europa.eu\/eli\/reg\/2021\/1323\/oj."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"648","DOI":"10.12688\/f1000research.121473.3","article-title":"Assessment of Arsenic, Vanadium, Mercury, and Cadmium in Food and Drug Packaging","volume":"4","author":"Mukhi","year":"2024","journal-title":"F1000Research"},{"key":"ref_31","unstructured":"European Commission (2021). Commission Regulation (EU) 2021\/1317 of 9 August 2021 amending Regulation (EC) No 1881\/2006 as regards maximum levels of lead in certain foodstuffs. Off. J. Eur. Union, L286, 1\u20134. Available online: http:\/\/data.europa.eu\/eli\/reg\/2021\/1317\/oj."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"5331","DOI":"10.1007\/s11356-023-31579-1","article-title":"Potential of herbaceous plant species for copper (Cu) accumulation","volume":"31","author":"Asare","year":"2024","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1007\/s11104-011-0974-9","article-title":"Distribution and variability of silicon, copper and zinc in different bamboo species","volume":"351","author":"Collin","year":"2012","journal-title":"Plant Soil"},{"key":"ref_34","first-page":"510","article-title":"Calculating the Silicon in Horsetail (Equisetum arvense L.) during the Vegetation Season","volume":"4","author":"Labun","year":"2013","journal-title":"Food Nutr. Sci."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Kraw\u0119cka, A., Sobota, A., Pankiewicz, U., Zieli\u0144ska, E., and Zarzycki, P. (2021). Stinging Nettle (Urtica dioica L.) as a Functional Component in Durum Wheat Pasta Production: Impact on Chemical Composition, In Vitro Glycemic Index, and Quality Properties. Molecules, 26.","DOI":"10.3390\/molecules26226909"}],"container-title":["Foods"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2304-8158\/15\/19\/3577\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T04:19:42Z","timestamp":1791951582000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2304-8158\/15\/19\/3577"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,8]]},"references-count":35,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["foods15193577"],"URL":"https:\/\/doi.org\/10.3390\/foods15193577","relation":{},"ISSN":["2304-8158"],"issn-type":[{"value":"2304-8158","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,8]]}}}