title: Rapid and automated analysis of aflatoxin M1 in milk and dairy products by online solid phase extraction coupled to ultra-high-pressure-liquid-chromatography tandem mass spectrometry.
abstract: This study reports a fast and automated analytical procedure for the analysis of aflatoxin M1 (AFM1) in milk and dairy products. The method is based on the simultaneous protein precipitation and AFM1 extraction, by salt-induced liquid-liquid extraction (SI-LLE), followed by an online solid-phase extraction (online SPE) coupled to ultra-high-pressure-liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis to the automatic pre-concentration, clean up and sensitive and selective determination of AFM1. The main parameters affecting the extraction efficiency and accuracy of the analytical method were studied in detail. In the optimal conditions, acetonitrile and NaCl were used as extraction/denaturant solvent and salting-out agent in SI-LLE, respectively. After centrifugation, the organic phase (acetonitrile) was diluted with water (1:9 v/v) and purified (1mL) by online C18 cartridge coupled with an UHPLC column. Finally, selected reaction monitoring (SRM) acquisition mode was applied to the detection of AFM1. Validation studies were carried out on different dairy products (whole and skimmed cow milk, yogurt, goat milk, and powder infant formula), providing method quantification limits about 25 times lower than AFM1 maximum levels permitted by EU regulation 1881/2006 in milk and dairy products for direct human consumption. Recoveries (86-102%) and repeatability (RSD<3, n=6) meet the performance criteria required by EU regulation N. 401/2006 for the determination of the levels of mycotoxins in foodstuffs. Moreover, no matrix effects were observed in the different milk and dairy products studied. The proposed method improves the performance of AFM1 analysis in milk samples as AFM1 determination is performed with a degree of accuracy higher than the conventional methods. Other advantages are the reduction of sample preparation procedure, time and cost of the analysis, enabling high sample throughput that meet the current concerns of food safety and the public health protection.
authors.affiliation: Dipartimento di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Campone
authors.affiliation: Dipartimento di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy. Electronic address: apiccine@unisa.it.
authors.forename: Anna Lisa
authors.initials: AL
authors.lastname: Piccinelli
authors.affiliation: Dipartimento di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Celano
authors.affiliation: Dipartimento di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
authors.forename: Imma
authors.initials: I
authors.lastname: Pagano
authors.affiliation: Dipartimento di Agraria, Università Mediterranea di Reggio Calabria, loc. Feo di Vito, 89122 Reggio Calabria, RC, Italy.
authors.forename: Mariateresa
authors.initials: M
authors.lastname: Russo
authors.affiliation: Dipartimento di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Rastrelli
mesh_terms: D016607:Aflatoxin M1 / Q000032:analysis*; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003611:Dairy Products / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D059625:Liquid-Liquid Extraction; D008892:Milk / Q000737:chemistry*; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D016607:Aflatoxin M1
keywords: Aflatoxin M1; Food safety; Milk and dairy products; Online SPE; Salt-induced LLE; UHPLC–MS/MS