Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements

Dietary supplements may contain heavy metals with the property of bioaccumulation in humans. The aim of this research was to validate and apply two analytical methods to determine Pb, As, Cr, and Hg in dietary supplements by Total Reflection X-ray Fluorescence Spectroscopy (TXRF). Methods validation...

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Main Authors: Blanca G. Beltrán, Victor Ramos-Sanchez, David Chávez-Flores, Rogelio Rodríguez-Maese, Edwin Palacio
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:Journal of Chemistry
Online Access:http://dx.doi.org/10.1155/2020/8817393
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author Blanca G. Beltrán
Victor Ramos-Sanchez
David Chávez-Flores
Rogelio Rodríguez-Maese
Edwin Palacio
author_facet Blanca G. Beltrán
Victor Ramos-Sanchez
David Chávez-Flores
Rogelio Rodríguez-Maese
Edwin Palacio
author_sort Blanca G. Beltrán
collection DOAJ
description Dietary supplements may contain heavy metals with the property of bioaccumulation in humans. The aim of this research was to validate and apply two analytical methods to determine Pb, As, Cr, and Hg in dietary supplements by Total Reflection X-ray Fluorescence Spectroscopy (TXRF). Methods validation was conducted through a multivariate analysis using a central composite design (CCD) and a desirability function. Critical values for each study variable were established. The TXRF_DS_1 method was proposed for Pb, As, and Cr determinations, while the TXRF_DS_2 was established for Hg analysis. The digestion method with an acid mixture (HNO3 + HCl + H2O2) was used to break down the organic material of dietary supplements. A solution of 10 μg L−1 Ga was used as an internal standard. Excellent analytical performance was obtained as LODs of 0.59, 0.41, 0.57, and 0.75 μg L−1 and LOQs of 1.95, 1.35, 1.90, and 2.50 μgL −1 for Pb, As, Cr, and Hg, respectively. Calibration curves showed a good linearity for all elements (R2>0.999). Excellent accuracy and precision in measurements (% RSD) was achieved. The real and spiked samples analysis demonstrated the applicability of the TXRF technique (percentage recovery 91–108%). Besides, two samples were analyzed in a comparison study between the TXRF_DS_1 method and the ICP-OES method. The results obtained showed good agreement between both techniques. The TXRF technique allows the analysis of toxic heavy metals in dietary supplements, which are marketed in a wide variety of presentations.
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spelling doaj-art-0c2b9c25ea394707887c381cf38580922025-08-20T03:54:19ZengWileyJournal of Chemistry2090-90632090-90712020-01-01202010.1155/2020/88173938817393Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary SupplementsBlanca G. Beltrán0Victor Ramos-Sanchez1David Chávez-Flores2Rogelio Rodríguez-Maese3Edwin Palacio4Faculty of Nursing and Nutriology, Chihuahua Autonomous University, Chihuahua 31125, MexicoFaculty of Chemical Sciences, Chihuahua Autonomous University, Chihuahua 31125, MexicoFaculty of Chemical Sciences, Chihuahua Autonomous University, Chihuahua 31125, MexicoEnvironment and Energy Department, Advances Materials Research Center (CIMAV) S.C, Miguel de Cervantes 120, Chihuahua 31109, MexicoLaboratory of Environmental Analytical Chemistry, University of the Balearic Islands, Cra. Valldemossa km 7’5 Palma de Mallorca, Palma, SpainDietary supplements may contain heavy metals with the property of bioaccumulation in humans. The aim of this research was to validate and apply two analytical methods to determine Pb, As, Cr, and Hg in dietary supplements by Total Reflection X-ray Fluorescence Spectroscopy (TXRF). Methods validation was conducted through a multivariate analysis using a central composite design (CCD) and a desirability function. Critical values for each study variable were established. The TXRF_DS_1 method was proposed for Pb, As, and Cr determinations, while the TXRF_DS_2 was established for Hg analysis. The digestion method with an acid mixture (HNO3 + HCl + H2O2) was used to break down the organic material of dietary supplements. A solution of 10 μg L−1 Ga was used as an internal standard. Excellent analytical performance was obtained as LODs of 0.59, 0.41, 0.57, and 0.75 μg L−1 and LOQs of 1.95, 1.35, 1.90, and 2.50 μgL −1 for Pb, As, Cr, and Hg, respectively. Calibration curves showed a good linearity for all elements (R2>0.999). Excellent accuracy and precision in measurements (% RSD) was achieved. The real and spiked samples analysis demonstrated the applicability of the TXRF technique (percentage recovery 91–108%). Besides, two samples were analyzed in a comparison study between the TXRF_DS_1 method and the ICP-OES method. The results obtained showed good agreement between both techniques. The TXRF technique allows the analysis of toxic heavy metals in dietary supplements, which are marketed in a wide variety of presentations.http://dx.doi.org/10.1155/2020/8817393
spellingShingle Blanca G. Beltrán
Victor Ramos-Sanchez
David Chávez-Flores
Rogelio Rodríguez-Maese
Edwin Palacio
Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements
Journal of Chemistry
title Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements
title_full Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements
title_fullStr Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements
title_full_unstemmed Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements
title_short Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements
title_sort total reflection x ray fluorescence spectroscopy txrf method validation determination of heavy metals in dietary supplements
url http://dx.doi.org/10.1155/2020/8817393
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