{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T02:07:19Z","timestamp":1776132439022,"version":"3.50.1"},"reference-count":45,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2020,12,9]],"date-time":"2020-12-09T00:00:00Z","timestamp":1607472000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this study, the use of weighted linear regression in the development of electrochemical methods for the determination of epinephrine (EP), ascorbic acid (AA), and uric acid (UA) is presented. The measurements were performed using a glassy carbon electrode and square-wave voltammetry (SWV). All electroanalytical methods were validated by determination of the limit of detection, limit of quantification, linear concentration range, accuracy, and precision. The normal distribution of all data sets was checked using the quantile-quantile plot and Kolmogorov-Smirnov statistical tests. The heteroscedasticity of the data was tested using Hartley\u2019s test, Bartlett\u2019s test, Cochran\u2019s C test, and the analysis of residuals. The heteroscedastic behavior was observed with all analytes, justifying the use of weighted linear regression. Six different weighting factors were tested, and the best weighted model was determined using relative percentage error. Such statistical approach improved the regression models by giving greater weight on the values with the smallest error and vice versa. Consequently, accuracy of the analytical results (especially in the lower concentration range) was improved. All methods were successfully used for the determination of these analytes in real samples: EP in an epinephrine auto-injector, AA in a dietary supplement, and UA in human urine. The accuracy and precision of real sample analysis using best weighted model gave satisfactory results with recoveries between 95.21\u2013113.23% and relative standard deviations between 0.85\u20137.98%. The SWV measurement takes about 40 s, which makes the presented methods for the determination of EP, AA, and UA a promising alternative to chromatographic techniques in terms of speed, analysis, and equipment costs, as the analysis is performed without organic solvents.<\/jats:p>","DOI":"10.3390\/s20247056","type":"journal-article","created":{"date-parts":[[2020,12,10]],"date-time":"2020-12-10T08:59:34Z","timestamp":1607590774000},"page":"7056","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["An Advanced Statistical Approach Using Weighted Linear Regression in Electroanalytical Method Development for Epinephrine, Uric Acid and Ascorbic Acid Determination"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7705-4996","authenticated-orcid":false,"given":"David","family":"Majer","sequence":"first","affiliation":[{"name":"Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tinkara","family":"Mastnak","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8302-9284","authenticated-orcid":false,"given":"Matja\u017e","family":"Fin\u0161gar","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,9]]},"reference":[{"key":"ref_1","unstructured":"Ellis, L., Farrington, D., and Hoskin, A. (2019). Handbook of Crime Correlates, Academic Press. [2nd ed.]."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Drobatz, K.J., Rozanski, K.H.E., and Silverstein, D.C. (2018). Mechanisms of heart failure. Textbook of Small Animal Emergency Medicine, John Wiley and Sons.","DOI":"10.1002\/9781119028994"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"5729","DOI":"10.1113\/JP274596","article-title":"The human ventilatory response to stress: Rate or depth?","volume":"595","author":"Tipton","year":"2017","journal-title":"J. Physiol."},{"key":"ref_4","first-page":"S829","article-title":"Part 12: Cardiac arrest in special situations","volume":"122","author":"Hoek","year":"2010","journal-title":"Circulation"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1726","DOI":"10.1056\/NEJMra1208943","article-title":"Circulatory shock","volume":"369","author":"Vincent","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_6","first-page":"105621","article-title":"A simple and efficient cyclic square wave voltametric method for simultaneous determination of epinephrine and norepinephrine using an activated pencil graphite electrode","volume":"160","author":"Popa","year":"2020","journal-title":"Microchem. J."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.microc.2018.02.008","article-title":"Exploiting CdSe\/ZnS core-shell photocatalyst modified with cytochrome c for epinephrine determination in drugs utilized in cardiopulmonary resuscitation","volume":"139","author":"Freires","year":"2018","journal-title":"Microchem. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"883","DOI":"10.1016\/j.microc.2018.12.003","article-title":"Electron rays irradiated polyaniline anchored over bovine serum albumin for simultaneous detection of epinephrine and uric acid","volume":"145","author":"Thivya","year":"2019","journal-title":"Microchem. J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"460","DOI":"10.1016\/j.microc.2017.04.014","article-title":"Electropolymerization of ferulic acid on multi-walled carbon nanotubes modified glassy carbon electrode as a versatile platform for NADH, dopamine and epinephrine separate detection","volume":"133","author":"Lopes","year":"2017","journal-title":"Microchem. J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.microc.2018.12.060","article-title":"A radiometric fluorometric epinephrine and norepinephrine assay based on carbon dot and CdTe quantum dots nanocomposites","volume":"146","author":"Zhang","year":"2019","journal-title":"Microchem. J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.ijcard.2015.08.109","article-title":"Regulation of uric acid metabolism and excretion","volume":"213","author":"Maiuolo","year":"2016","journal-title":"Int. J. Cardiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"400","DOI":"10.1007\/s11926-013-0400-9","article-title":"The crystallization of monosodium urate","volume":"16","author":"Martillo","year":"2013","journal-title":"Curr. Rheumatol. Rep."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"104642","DOI":"10.1016\/j.microc.2020.104642","article-title":"In situ formation of Ag\/Au nanorods as a platform to design a non-aggregation colorimetric assay for uric acid detection in biological fluids","volume":"154","author":"Amjadi","year":"2020","journal-title":"Microchem. J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"104841","DOI":"10.1016\/j.microc.2020.104841","article-title":"S, N-doped carbon quantum dots enhanced Luminol-Mn(IV) chemiluminescence reaction for detection of uric acid in biological fluids","volume":"156","author":"Hallaj","year":"2020","journal-title":"Microchem. J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"104745","DOI":"10.1016\/j.microc.2020.104745","article-title":"Non-enzymatic electrochemical sensor for the simultaneous determination of adenosine, adenine and uric acid in whole blood and urine","volume":"155","author":"Krishnan","year":"2020","journal-title":"Microchem. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"104379","DOI":"10.1016\/j.microc.2019.104379","article-title":"Novel electrochemical sensor using a dual-working electrode system for the simultaneous determination of glucose, uric acid and dopamine","volume":"153","author":"Soleh","year":"2020","journal-title":"Microchem. J."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Stanger, O. (2012). Vitamin C transport and its role in the central nervous system. Water Soluble Vitamins: Clinical Research and Future Application, Springer.","DOI":"10.1007\/978-94-007-2199-9"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"104927","DOI":"10.1016\/j.microc.2020.104927","article-title":"Simultaneous voltammetric determination of ascorbic acid, dopamine, acetaminophen and tryptophan based on hybrid trimetallic nanoparticles-capped electropretreated graphene","volume":"156","author":"Abdelwahab","year":"2020","journal-title":"Microchem. J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"105534","DOI":"10.1016\/j.microc.2020.105534","article-title":"Non-enzymatic simultaneous detection of acetylcholine and ascorbic acid using ZnO\u00b7CuO nanoleaves: Real sample analysis","volume":"159","author":"Asiri","year":"2020","journal-title":"Microchem. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"105470","DOI":"10.1016\/j.microc.2020.105470","article-title":"Application of carbon nanoonion-NiMoO4-MnWO4 nanocomposite for modification of glassy carbon electrode: Electrochemical determination of ascorbic acid","volume":"159","author":"Naghian","year":"2020","journal-title":"Microchem. J."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1016\/j.talanta.2015.10.017","article-title":"Selective enrichment and determination of monoamine neurotransmitters by CU(II) immobilized magnetic solid phase extraction coupled with high-performance liquid chromatography-fluorescence detection","volume":"147","author":"He","year":"2016","journal-title":"Talanta"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2931","DOI":"10.1007\/s00216-017-0239-4","article-title":"Determination of monoamine neurotransmitters in zebrafish (Danio rerio) by gas chromatography coupled to mass spectrometry with a two-step derivatization","volume":"409","author":"Aragon","year":"2017","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Vladislavi\u0107, N., Ron\u010devi\u0107 \u0160kugor, I., Buzuk, M., Buljac, M., and Drventi\u0107, I. (2020). Electrochemical\/chemical synthesis of hydroxyapatite on glassy carbon electrode for electroanalytical determination of cysteine. J. Solid State Electrochem., 1\u201317.","DOI":"10.1007\/s10008-020-04856-z"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Vladislavi\u0107, N., Ron\u010devi\u0107 \u0160kugor, I., Buljac, M., Brini\u0107, S., Krivi\u010d, D., and Buzuk, M. (2018). Electroanalytical determination of cysteine using the electrodes based on ternary silver-copper sulfides. Sensors, 18.","DOI":"10.3390\/s18113753"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Moosavi, M., and Ghassabian, S. (2018). Linearity of calibration curves for analytical methods: A review of criteria for assessment of method reliability. Calibration and Validation of Analytical Methods\u2014A Sampling of Current Approaches, IntechOpen Limited.","DOI":"10.5772\/intechopen.72932"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s40543-018-0160-2","article-title":"An approach to select linear regression model in bioanalytical method validation","volume":"10","author":"Sonawane","year":"2019","journal-title":"J. Anal. Sci. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/S1570-0232(02)00244-1","article-title":"Linear regression for calibration lines revisited: Weighting schemes for bioanalytical methods","volume":"774","author":"Almeida","year":"2002","journal-title":"J. Chromatogr. B"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"112965","DOI":"10.1016\/j.jpba.2019.112965","article-title":"Why should the pharmaceutical industry claim for the implementation of second order chemometric models\u2014A critical review","volume":"179","author":"Vignaduzzo","year":"2020","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/j.aca.2019.10.053","article-title":"On second-order calibration based on multivariate curve resolution in the presence of highly overlapped profiles","volume":"1096","author":"Alcaraz","year":"2020","journal-title":"Anal. Chim. Acta"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.aca.2019.06.038","article-title":"Contribution to second-order calibration based on multivariate curve resolution with and without previous chromatographic synchronization","volume":"1078","author":"Olivieri","year":"2019","journal-title":"Anal. Chim. Acta"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"104635","DOI":"10.1016\/j.microc.2020.104635","article-title":"Copper-bismuth-film in situ electrodes for heavy metal detection","volume":"154","year":"2020","journal-title":"Microchem. J."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"465","DOI":"10.2174\/1573411014666180704114202","article-title":"Cyclic voltammetry as an electroanalytical tool for analysing the reaction mechanisms of copper in chloride solution containing different azole compounds","volume":"16","author":"Xhanari","year":"2020","journal-title":"Curr. Anal. Chem."},{"key":"ref_33","unstructured":"Massart, D.L., Vandeginste, B.G.M., Buydens, L.M., Jong, S.D., Lewi, P.J., and Smeyers-Verbeke, J. (1997). Handbook of Chemometrics and Qualimetrics: Part, A, Elsevier."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"124038","DOI":"10.1016\/j.colsurfa.2019.124038","article-title":"A simple sonochemical assisted synthesis of nanocomposite (ZnO\/MWCNTs) for electrochemical sensing of Epinephrine in human serum and pharmaceutical formulation","volume":"584","author":"Shaikshavali","year":"2020","journal-title":"Colloids Surf. A"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1653","DOI":"10.1002\/elan.201800024","article-title":"New insight into the EC\u2019 mechanism of uric acid regeneration in the presence of ascorbic acid on a poly(3,4-ethylenedioxithiophene) modified gold electrode","volume":"30","author":"Latapie","year":"2018","journal-title":"Electroanalysis"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"10166","DOI":"10.3390\/s111110166","article-title":"Electrocatalytic oxidation of ascorbic acid using a poly(aniline-co-m-ferrocenylaniline) modified glassy carbon electrode","volume":"11","author":"Chairam","year":"2011","journal-title":"Sensors"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1016\/j.jksus.2017.05.016","article-title":"Development and validation of stability indicating HPLC method for determination of adrenaline tartrate","volume":"31","author":"Kongkiatpaiboon","year":"2019","journal-title":"J. King Saud Univ. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1097","DOI":"10.1007\/s12161-011-9347-5","article-title":"Optimization and validation of a UV\u2013HPLC method for vitamin C determination in strawberries (Fragaria ananassa Duch.), using experimental designs","volume":"5","author":"Pirovani","year":"2012","journal-title":"Food Anal. Methods"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1647923","DOI":"10.1155\/2018\/1647923","article-title":"Development and validation of a simple highperformance liquid chromatography\/UV Method for simultaneous determination of urinary uric acid, hypoxanthine, and creatinine in human urine","volume":"2018","author":"Wijemanne","year":"2018","journal-title":"Int. J. Anal. Chem."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"848","DOI":"10.1016\/j.jpba.2010.12.018","article-title":"Advances in validation, risk and uncertainty assessment of bioanalytical methods","volume":"55","author":"Rozet","year":"2011","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1093\/jat\/bkx002","article-title":"Procedure for the selection and validation of a calibration model I\u2014Description and application","volume":"41","author":"Desharnais","year":"2017","journal-title":"J. Anal. Toxicol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"705","DOI":"10.1021\/ed077p705.2","article-title":"Modern Analytical Chemistry, 1st Edition (Harvey, David)","volume":"77","author":"Goldsmith","year":"2000","journal-title":"J. Chem. Educ."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1016\/j.talanta.2014.07.041","article-title":"Method validation using weighted linear regression models for quantification of UV filters in water samples","volume":"131","year":"2015","journal-title":"Talanta"},{"key":"ref_44","unstructured":"Food and Drug Administration (FDA) (2018). Bioanalytical Method Validation: Guidance for Industry, Food and Drug Administration."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1319","DOI":"10.1002\/1521-4109(200111)13:16<1319::AID-ELAN1319>3.0.CO;2-C","article-title":"Determination of uric acid at electrochemically activated glassy carbon electrode","volume":"13","author":"Shi","year":"2001","journal-title":"Electroanalysis"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/24\/7056\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:42:57Z","timestamp":1760179377000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/24\/7056"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,9]]},"references-count":45,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2020,12]]}},"alternative-id":["s20247056"],"URL":"https:\/\/doi.org\/10.3390\/s20247056","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12,9]]}}}