{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:43:39Z","timestamp":1760240619711,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2019,8,9]],"date-time":"2019-08-09T00:00:00Z","timestamp":1565308800000},"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":["UID\/QUI\/50006\/2019"],"award-info":[{"award-number":["UID\/QUI\/50006\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["POCI\/01\/0145\/FEDER\/007265"],"award-info":[{"award-number":["POCI\/01\/0145\/FEDER\/007265"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The micro sequential injection analysis \/ lab-on-valve (\u00b5SIA-LOV) system is a miniaturized SIA system resulting from the implementation of a lab-on-valve (LOV) atop of the selection valve. It integrates the detection cell and the sample processing channels into the same device, promoting the reduction of reagent consumption and waste generation, the improvement of the versatility, and the reduction of the time of analysis. All of these characteristics are really relevant to the implementation of enzymatic reactions. Additionally, the evaluation of cholesterol in serum samples is widely relevant in clinical diagnosis, since higher values of cholesterol in human blood are actually an important risk factor for cardiovascular problems. An automatic methodology was developed based on the \u00b5SIA-LOV system in order to evaluate its advantages in the implementation of enzymatic reactions performed by cholesterol esterase, cholesterol oxidase and peroxidase. Considering these reactions, the developed methodology was also used for the evaluation of cholesterol in human serum samples, showing reliable and accurate results. The developed methodology presented detection and quantification limits of 1.36 and 4.53 mg dL\u22121 and a linear range up to 40 mg dL\u22121. This work confirmed that this \u00b5SIA-LOV system is a simple, rapid, versatile, and robust analytical tool for the automatic implementation of enzymatic reactions performed by cholesterol esterase, cholesterol oxidase, and peroxidase. It is also a useful alternative methodology for the routine determinations of cholesterol in real samples, even when compared with other automatic methodologies.<\/jats:p>","DOI":"10.3390\/molecules24162890","type":"journal-article","created":{"date-parts":[[2019,8,9]],"date-time":"2019-08-09T11:11:31Z","timestamp":1565349091000},"page":"2890","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Enzymatic Reactions in a Lab-on-Valve System: Cholesterol Evaluations"],"prefix":"10.3390","volume":"24","author":[{"given":"Jucineide","family":"S. Barbosa","sequence":"first","affiliation":[{"name":"LAQV, REQUIMTE, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"},{"name":"Instituto de Qu\u00edmica, Departamento de Qu\u00edmica Anal\u00edtica, Campus Universit\u00e1rio de Ondina, Universidade Federal da Bahia, 40170-115 Salvador, Bahia, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1383-4405","authenticated-orcid":false,"given":"Marieta","family":"L.C. Passos","sequence":"additional","affiliation":[{"name":"LAQV, REQUIMTE, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"}]},{"given":"M. das Gra\u00e7as","family":"A. Korn","sequence":"additional","affiliation":[{"name":"Instituto de Qu\u00edmica, Departamento de Qu\u00edmica Anal\u00edtica, Campus Universit\u00e1rio de Ondina, Universidade Federal da Bahia, 40170-115 Salvador, Bahia, Brazil"},{"name":"INCT de Energia e Ambiente\u2013Instituto de Qu\u00edmica, Campus Universit\u00e1rio de Ondina, Universidade Federal da Bahia, 40170-115 Salvador, Bahia, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6539-1741","authenticated-orcid":false,"given":"M. L\u00facia","family":"M.F.S. Saraiva","sequence":"additional","affiliation":[{"name":"LAQV, REQUIMTE, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,8,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1016\/j.aca.2011.01.048","article-title":"Enzyme based assays in a sequential injection format: A review","volume":"689","author":"Silvestre","year":"2011","journal-title":"Anal. Chim. Acta"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"687","DOI":"10.2116\/analsci.25.687","article-title":"Enzymatic determination of glucose in milk samples by sequential injection analysis","volume":"25","author":"Araujo","year":"2009","journal-title":"Anal. 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