{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T12:10:03Z","timestamp":1790424603007,"version":"4.1.0"},"reference-count":30,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T00:00:00Z","timestamp":1771286400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Agency for Scientific Research and Innovation (NASRI) in Albania","award":["999\/7 Prot."],"award-info":[{"award-number":["999\/7 Prot."]}]},{"name":"Food Safety and Veterinary Institute (ISUV), Albania"},{"DOI":"10.13039\/501100001604","name":"Teagasc","doi-asserted-by":"crossref","award":["NFSA1467"],"award-info":[{"award-number":["NFSA1467"]}],"id":[{"id":"10.13039\/501100001604","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Nitrofurans are banned veterinary medicinal products due to their carcinogenic and mutagenic properties; however, their protein-bound metabolites (AOZ, AMOZ, AHD, SEM, and DNSAH) may persist in food-producing animals, particularly in eggs. Reliable confirmatory methods are therefore essential for residue monitoring under the stringent requirements of Commission Implementing Regulation (EU) 2021\/808. This study reports the development and validation of a sensitive and selective LC\u2013MS\/MS method combining acid hydrolysis, 2-nitrobenzaldehyde derivatization, and QuEChERS extraction for the determination of nitrofuran metabolites in eggs. Chromatographic separation was carried out using a phenyl-hexyl column, and detection using a tandem mass spectrometer, supported by isotope-labeled internal standards, ensured robust identification and quantification. Linearity was satisfactory over the investigated concentration range (R2 &gt; 0.99), with recoveries between 82 and 109%. The method\u2019s precision was acceptable, with repeatability RSD values below 10% and within-laboratory reproducibility RSD values below 22%. Matrix effects were effectively controlled, remaining within \u00b120% following internal standard normalization. Decision limits (CC\u03b1) ranged from 0.29 to 0.37 \u00b5g\/kg, well below the EU reference point for action of 0.5 \u00b5g\/kg. The method\u2019s performance was further confirmed through participation in an accredited proficiency test scheme. Overall, the validated method provides a reliable analytical tool for routine official control laboratories, enabling the sensitive confirmatory detection of banned nitrofuran residues in eggs and supporting food safety and regulatory compliance.<\/jats:p>","DOI":"10.3390\/molecules31040700","type":"journal-article","created":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T13:15:35Z","timestamp":1771334135000},"page":"700","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Development and Validation of a Confirmatory LC-MS\/MS Method Using QuEChERS for Determination of Nitrofuran Metabolites in Eggs According to EU Regulation 2021\/808"],"prefix":"10.3390","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-4098-1372","authenticated-orcid":false,"given":"Elmira","family":"Marku","sequence":"first","affiliation":[{"name":"Food Safety and Veterinary Institute, Rr. Aleksand\u00ebr Moisiu, Nr. 82, 2020 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-8890-6823","authenticated-orcid":false,"given":"Kozeta","family":"Vaso","sequence":"additional","affiliation":[{"name":"Chemistry Department, Faculty of Natural Sciences, University of Tirana, Bulevardi \u201cZogu I\u201d, Nr. 25, 1001 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4060-0441","authenticated-orcid":false,"given":"Martin","family":"Danaher","sequence":"additional","affiliation":[{"name":"Food Safety Department, Teagasc Food Research Centre, Ashtown, D15 DYO5 Dublin, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2138-4344","authenticated-orcid":false,"given":"Erinda","family":"Pllaha","sequence":"additional","affiliation":[{"name":"Food Safety and Veterinary Institute, Rr. Aleksand\u00ebr Moisiu, Nr. 82, 2020 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-3689-7736","authenticated-orcid":false,"given":"Suela","family":"Teqja","sequence":"additional","affiliation":[{"name":"Food Safety and Veterinary Institute, Rr. Aleksand\u00ebr Moisiu, Nr. 82, 2020 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-5463-8555","authenticated-orcid":false,"given":"Jonida","family":"Canaj","sequence":"additional","affiliation":[{"name":"Chemistry Department, Faculty of Natural Sciences, University of Tirana, Bulevardi \u201cZogu I\u201d, Nr. 25, 1001 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3448-9148","authenticated-orcid":false,"given":"Ina","family":"Pasho","sequence":"additional","affiliation":[{"name":"Chemistry Department, Faculty of Natural Sciences, University of Tirana, Bulevardi \u201cZogu I\u201d, Nr. 25, 1001 Tirana, Albania"},{"name":"Novartis Pharma Albania & Kosovo & North Macedonia, 1001 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ilir","family":"Ajdini","sequence":"additional","affiliation":[{"name":"Food Safety and Veterinary Institute, Rr. Aleksand\u00ebr Moisiu, Nr. 82, 2020 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"EFSA (2015). Scientific Opinion on nitrofurans and their metabolites in food. EFSA J., 13, 4140.","DOI":"10.2903\/j.efsa.2015.4140"},{"key":"#cr-split#-ref_2.1","unstructured":"European Commission (1995). Commission Regulation"},{"key":"#cr-split#-ref_2.2","unstructured":"(EC) No 1442\/95 of 26 June 1995 amending Annexes I, II, III and IV of Council Regulation (EEC) No 2377\/90 laying down a Community procedure for the establishment of maximum residue limits of veterinary medicinal products in foodstuffs of animal origin, European Commission."},{"key":"#cr-split#-ref_3.1","unstructured":"European Commission (2019). 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