Residue analysis of nitrofuran metabolites in five food commodities from Croatia using ultra-high performance liquid chromatography–tandem mass spectrometry

• Published in: Journal of food composition and analysis 2023-10, Vol.123, p.105614, Article 105614
• Main Authors: Varga, Ines, Luburić, Đurđica Božić, Varenina, Ivana, Kolanović, Božica Solomun, Čalopek, Bruno, Sedak, Marija, Vratarić, Darija, Bilandžić, Nina, Đokić, Maja
• Format: Article
• Language: English
• Subjects: Croatia; derivatization; ethyl acetate; food composition; Food safety; honey; hydrazine; hydrolysis; laws and regulations; metabolites; milk; muscles; Nitrofurans; Non-compliant samples; Prohibited substances; tandem mass spectrometry; UHPLC-MS/MS; ultra-performance liquid chromatography; Validation
• ISSN: 0889-1575
• DOI: 10.1016/j.jfca.2023.105614

The aim of the current study was to validate a screening and confirmatory method for the determination of nitrofuran residues: 3-amino-2-oxazolidinone (AOZ), 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ), 1-aminohydantoin (AHD), semicarbazide (SEM), 3,5-dinitrosalicylic acid hydrazine (DNSAH), nifurpirinol (NPIR), nifuroxazide (metabolite 4-HBH), and nitrovin (metabolite AMG) in muscle, milk, eggs, honey, and casings, in accordance with the legislation 2002/657/EC and 2021/808/EC. Sample preparation included hydrolysis and derivatization, followed by ethyl acetate extraction and measurement by ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). Validation parameters specified in this method are specificity/selectivity, trueness, precision, decision limit (CCα), and detection capability (CCβ). In the screening method, the CCβ value ranged from 0.275 to 0.582 µg kg-1, while in the confirmatory method, the CCα value ranged from 0.264 to 0.407 µg kg-1. The recovery values ranged from 93.5% to 127.5%. A total of 497 routine samples from the National Residue Monitoring Control Plan (NRCP) and border inspection were analysed from 2021 to 2022. SEM was detected in a total of 11 samples. Only four samples had a concentration above the Reference Point for Action (RPA = 0.5 µg kg-1). The validated method is suitable for monitoring nitrofuran residues at levels below the recently established RPA. •A sensitive UHPLC-MS/MS method for the analysis of eight nitrofurans was validated.•New analytes were introduced: nifursol, nifuroxazide, nitrovin, and nifurpirinol.•Method validation was performed on muscle, milk, eggs, honey, and casings.•The validated method was used for the analysis of 497 routine samples.•This method is applicable for monitoring nitrofuran residues in various matrices.