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Lourenço FR, Oliveira ECD. Nonparametric estimation of measurement uncertainty arising from sampling. Anal Chim Acta 2024; 1305:342597. [PMID: 38677839 DOI: 10.1016/j.aca.2024.342597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/20/2024] [Accepted: 04/09/2024] [Indexed: 04/29/2024]
Abstract
BACKGROUND Increasingly, measurement uncertainty has been used by pure and applied analytical chemistry to ensure decision-making in commercial transactions and technical-scientific applications. Until recently, it was considered that measurement uncertainty boiled down to analytical uncertainty; however, over the last two decades, uncertainty arising from sampling has also been considered. However, the second version of the EURACHEM guide, published in 2019, assumes that the frequency distribution is approximately normal or can be normalized through logarithmic transformations, without treating data that deviate from the normality. RESULTS Here, six examples (four from Eurachem guide) were treated by classical ANOVA and submitted to an innovative nonparametric approach for estimating the uncertainty contribution arising from sampling. Based on bootstrapping method, confidence intervals were used to guarantee metrological compatibility between the uncertainty ratios arising from the results of the traditional parametric tests and the unprecedented proposed nonparametric methodology. SIGNIFICANCE AND NOVELTY The present study proposed an innovative methodology for covering this gap in the literature based on nonparametric statistics (NONPANOVA) using the median absolute deviation concepts. Supplementary material based on Excel spreadsheets was developed, assisting users in the statistical treatment of their real examples.
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Affiliation(s)
- Felipe Rebello Lourenço
- Programa de Pós-Graduação em Fármaco e Medicamentos, Departamento de Farmácia, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Brazil
| | - Elcio Cruz de Oliveira
- Postgraduate Programme in Metrology, Pontifical Catholic University of Rio de Janeiro, Marquês de São Vicente Street, 225, Gávea, Rio de Janeiro, RJ, Brazil; Logistics, Land Transportation and Storage, Measurement and Product Inventory Management PETROBRAS S.A., Av. Henrique Valadares 28, 20231-030, Rio de Janeiro, Brazil.
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Pereira WDP, Carvalheira L, Lopes JM, Aguiar PFD, Moreira RM, Oliveira ECD. Data reconciliation connected to guard bands to set specification limits related to risk assessment for radiopharmaceutical activity. Heliyon 2023; 9:e22992. [PMID: 38125475 PMCID: PMC10731080 DOI: 10.1016/j.heliyon.2023.e22992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/23/2023] Open
Abstract
Radiopharmaceuticals have been used to diagnose several diseases, particularly because the procedure is non-invasive. However, it is important that the correct amount of radiopharmaceutical is used to avoid inaccurate diagnostic results and suboptimal therapeutic outcomes. The amount of the radiopharmaceutical is measured when produced (by the supplier) and a second time (by the receiver), before it's use. When measured at the receiver, the result is corrected for its normal radioactivity decay. Even then, it is possible that both measurements should be considered nominal different or even statistically different when compared through various statistical tools. This research combines two innovative techniques in the field of clinical metrology. The first technique is data reconciliation, which not only enhances measurement accuracy but also reduces measurement uncertainty. The second technique involves using uncertainty information to establish specification limits for compliance assessments. In this way, our proposal aimed to minimize the risk of making incorrect decisions regarding the conformity of the concentration of radiopharmaceutical activity, that is, rejecting an item or batch that is within specification or accepting an item or batch that is outside of specification. A spreadsheet, based on these metrology fundamentals, is available to help the user with the calculations, presenting numerical and graphical results for some common radioisotopes. Reliable specification limits can be calculated and used to determine if the radiopharmaceutical is in accordance with its proposed application.
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Affiliation(s)
| | - Luciana Carvalheira
- Argonauta Reactor Service, Nuclear Engineering Institute, R. Hélio de Almeida 75, 21941-614, Rio de Janeiro, Brazil
| | - José Marques Lopes
- Earth and Environmental Physics Department, Physics Institute, Federal University of Bahia, Campus Universitário de Ondina, 40210-340, Salvador, Brazil
- Postgraduate Program in Geochemistry, Petroleum and Environment (POSPETRO), Federal University of Bahia, Av. Milton Santos s/n°, Salvador, 40170-110, Brazil
| | - Paula Fernandes de Aguiar
- Federal University of Rio de Janeiro, Chemistry Institute, Avenida Athos da Silveira Ramos 149, 21941-909, Rio de Janeiro, Brazil
| | - Rosana Medeiros Moreira
- National Institute of Technology, Av. Venezuela 82 20081-312, Rio de Janeiro, Brazil
- National Institute of Metrology, Quality and Technology (INMETRO), Av. Nossa Senhora das Graças 50, 25250-020, Duque de Caxias, Brazil
| | - Elcio Cruz de Oliveira
- Postgraduate Programme in Metrology, Pontifical Catholic University of Rio de Janeiro, R. Marquês de São Vicente 225, 22451-900, Rio de Janeiro, Brazil
- Logistics, Operational Planning and Control, Measurement and Product Inventory Management, PETROBRAS S.A., Av. Henrique Valadares 28, 20231-030, Rio de Janeiro, Brazil
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Carvalheira L, Lopes JM, Fernandes de Aguiar P, Cruz de Oliveira E. Compliance assessment when radioactive discharges are close to exemption levels in nuclear medicine facilities. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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