title: Confirmation and 3D profiling of anabolic steroid esters in injection sites using imaging desorption electrospray ionisation (DESI) mass spectrometry.
abstract: In this study, desorption electrospray ionisation (DESI) linear ion trap tandem mass spectrometry (MS(n)) was applied for the confirmation and three-dimensional profiling of anabolic steroid esters in an injection site of bovine muscle. The spatial resolution of the DESI-MS(n) was demonstrated by scanning hormone esters and marker ink lines drawn at various distances on a microscopic slide at set distances, using an x-scanner with manual y and z adjustment. Tissue slices of bovine muscle injected with a hormone cocktail were analysed. All anabolic steroid esters could be directly detected in the sample and confirmed on the basis of identification points awarded for selected MS/MS transitions according to the performance criteria given in Commission Decision 2002/657/EC. Moreover, the injection site could be mapped by two-dimensional and three-dimensional imaging MS, showing a horizontal and vertical distribution through the muscle tissue. This DESI approach offers potential for analysis of injection sites of steroid esters from illegally treated animals; moreover, direct analysis by ambient imaging DESI-MS still allows conventional extraction and analysis of the whole tissue for further confirmatory or contra-analysis afterwards.
authors.affiliation: RIKILT - Institute of Food Safety, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands. eva.derijke@wur.nl
authors.forename: Eva
authors.initials: E
authors.lastname: de Rijke
authors.forename: Dick
authors.initials: D
authors.lastname: Hooijerink
authors.forename: Saskia S
authors.initials: SS
authors.lastname: Sterk
authors.forename: Michel W F
authors.initials: MW
authors.lastname: Nielen
mesh_terms: D045930:Anabolic Agents / Q000032:analysis* / Q000737:chemistry; D000818:Animals; D002417:Cattle; D004952:Esters; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013256:Steroids / Q000032:analysis* / Q000737:chemistry
chemical_list: D045930:Anabolic Agents; D004952:Esters; D013256:Steroids