title: Rapid Screening Technique To Identify Sudan Dyes (I to IV) in Adulterated Tomato Sauce, Chilli Powder, and Palm Oil by Innovative High-Resolution Mass Spectrometry.
abstract: Sudan dyes are synthetic azo dyes used by industry in a variety of applications. Classified as carcinogenic, they are not allowed in foodstuffs; however, their presence as adulterants in food products has been regularly reported. Here, we describe an innovative screening method to detect Sudan I, II, III, and IV in tomato sauce, palm oil, and chilli powder. The method entails minimal sample preparation, completely avoiding the liquid chromatography phase, followed by detection and identification through atmospheric pressure chemical ionization time-of-flight mass spectrometry, in positive ionization mode. Analytes were efficiently identified and detected in samples, fortified both with individual analytes and with their mixture, with an error in mass identification less than 5 ppm. Limits of identification of the analytes in the fortified samples were 0.5 to 1 mg/kg, depending on the dye and matrix. The method had a linear range of 0.05 to 5 mg/kg and good linear relationships (R2> 0.98). Repeatability was satisfactory, with a coefficient of variation lower than 20%. The method was applied to detect the dyes in real adulterated chilli samples, previously found positive by confirmatory high-performance liquid chromatography-mass spectrometry and ELISA, and in commercial products purchased from supermarkets. In all positive samples, analytes were correctly identified with an error in mass identification lower than 5 ppm, while none of the 45 commercial samples analyzed were found to be contaminated. The proposed new assay is sensitive, with a limit of identification, for all the three matrices, complying with the limits defined by the European Union (0.5 to 1 mg/kg) for analytical methods. Compared with conventional methods, the new assay is rapid and inexpensive and characterized by a high throughput; thus, it could be suitable as screening technique to identify Sudan dyes in adulterated food products.
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta; Genetics and Immunobiochemistry Laboratory, via Bologna 148, 10154, Turin, Italy (ORCID: http://orcid.org/0000-0002-6791-657X [F.M.]).
authors.forename: Simona
authors.initials: S
authors.lastname: Sciuto
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta; Genetics and Immunobiochemistry Laboratory, via Bologna 148, 10154, Turin, Italy (ORCID: http://orcid.org/0000-0002-6791-657X [F.M.]).
authors.forename: Giovanna
authors.initials: G
authors.lastname: Esposito
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta; Genetics and Immunobiochemistry Laboratory, via Bologna 148, 10154, Turin, Italy (ORCID: http://orcid.org/0000-0002-6791-657X [F.M.]).
authors.forename: Luana
authors.initials: L
authors.lastname: Dell'Atti
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta; Genetics and Immunobiochemistry Laboratory, via Bologna 148, 10154, Turin, Italy (ORCID: http://orcid.org/0000-0002-6791-657X [F.M.]).
authors.forename: Chiara
authors.initials: C
authors.lastname: Guglielmetti
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta; Genetics and Immunobiochemistry Laboratory, via Bologna 148, 10154, Turin, Italy (ORCID: http://orcid.org/0000-0002-6791-657X [F.M.]).
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Acutis
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta; Genetics and Immunobiochemistry Laboratory, via Bologna 148, 10154, Turin, Italy (ORCID: http://orcid.org/0000-0002-6791-657X [F.M.]).
authors.forename: Francesca
authors.initials: F
authors.lastname: Martucci
mesh_terms: D001391:Azo Compounds; D002851:Chromatography, High Pressure Liquid; D004396:Coloring Agents; D018551:Solanum lycopersicum; D000073878:Palm Oil; D010938:Plant Oils; D013397:Sudan
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D010938:Plant Oils; D000073878:Palm Oil
keywords: Direct sample analysis; Food fraud; Mass spectrometry; Sudan dyes