title: Determination of peanut allergens in cereal-chocolate-based snacks: metal-tag inductively coupled plasma mass spectrometry immunoassay versus liquid chromatography/electrospray ionization tandem mass spectrometry.
abstract: A comparison of two methods for the identification and determination of peanut allergens based on europium (Eu)-tagged inductively coupled plasma mass spectrometry (ICP-MS) immunoassay and on liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) with a triple quadrupole mass analyzer was carried out on a complex food matrix like a chocolate rice crispy-based snack. The LC/MS/MS method was based on the determination of four different peptide biomarkers selective for the Ara h2 and Ara h3/4 peanut proteins. The performance of this method was compared with that of a non-competitive sandwich enzyme-linked immunosorbent assay (ELISA) method with ICP-MS detection of the metal used to tag the antibody for the quantitative peanut protein analysis in food. The limit of detection (LOD) and quantitation of the ICP-MS immunoassay were 2.2 and 5 microg peanuts g(-1) matrix, respectively, the recovery ranged from 86 +/- 18% to 110 +/- 4% and linearity was proved in the 5-50 microg g(-1) range. The LC/MS/MS method allowed us to obtain LODs of 1 and 5 microg protein g(-1) matrix for Ara h3/4 and Ara h2, respectively, thus obtaining significantly higher values with respect to the ELISA ICP-MS method, taking into account the different expression for concentrations. Linearity was established in the 10-200 microg g(-1) range of peanut proteins in the food matrix investigated and good precision (RSD <10%) was demonstrated. Both the two approaches, used for screening or confirmative purposes, showed the power of mass spectrometry when used as a very selective detector in difficult matrices even if some limitations still exist, i.e. matrix suppression in the LC/ESI-MS/MS procedure and the change of the Ag/Ab binding with matrix in the ICP-MS method.
authors.affiliation: Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, Viale G.P. Usberti 17/A, I-43100 Parma, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Careri
authors.forename: Lisa
authors.initials: L
authors.lastname: Elviri
authors.forename: Monica
authors.initials: M
authors.lastname: Maffini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mangia
authors.forename: Claudio
authors.initials: C
authors.lastname: Mucchino
authors.forename: Mattia
authors.initials: M
authors.lastname: Terenghi
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000276:immunology; D010367:Arachis / Q000737:chemistry*; D002099:Cacao / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002523:Edible Grain / Q000737:chemistry*; D005504:Food Analysis / Q000379:methods*; D006358:Hot Temperature; D007118:Immunoassay / Q000379:methods*; D008670:Metals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013194:Staining and Labeling / Q000379:methods
chemical_list: D000485:Allergens; D008670:Metals