title: Investigation of the Impact of Desorption Electrospray Ionization Sprayer Geometry on Its Performance in Imaging of Biological Tissue.
abstract: In this study, the impact of sprayer design and geometry on performance in desorption electrospray ionization mass spectrometry (DESI-MS) is assessed, as the sprayer is thought to be a major source of variability. Absolute intensity repeatability, spectral composition, and classification accuracy for biological tissues are considered. Marked differences in tissue analysis performance are seen between the commercially available and a lab-built sprayer. These are thought to be associated with the geometry of the solvent capillary and the resulting shape of the primary electrospray. Experiments with a sprayer with a fixed solvent capillary position show that capillary orientation has a crucial impact on tissue complex lipid signal and can lead to an almost complete loss of signal. Absolute intensity repeatability is compared for five lab-built sprayers using pork liver sections. Repeatability ranges from 1 to 224% for individual sprayers and peaks of different spectral abundance. Between sprayers, repeatability is 16%, 9%, 23%, and 34% for high, medium, low, and very low abundance peaks, respectively. To assess the impact of sprayer variability on tissue classification using multivariate statistical tools, nine human colorectal adenocarcinoma sections are analyzed with three lab-built sprayers, and classification accuracy for adenocarcinoma versus the surrounding stroma is assessed. It ranges from 80.7 to 94.5% between the three sprayers and is 86.5% overall. The presented results confirm that the sprayer setup needs to be closely controlled to obtain reliable data, and a new sprayer setup with a fixed solvent capillary geometry should be developed.
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, United Kingdom.|NiCE-MSI, National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom.
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Tillner
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: James S
authors.initials: JS
authors.lastname: McKenzie
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: Emrys A
authors.initials: EA
authors.lastname: Jones
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: Abigail V M
authors.initials: AV
authors.lastname: Speller
authors.affiliation: Department of Electrical, Engineering and Electronics, University of Liverpool , Brownlow Hill, Liverpool L69 3GJ, United Kingdom.
authors.forename: James L
authors.initials: JL
authors.lastname: Walsh
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: Kirill A
authors.initials: KA
authors.lastname: Veselkov
authors.affiliation: NiCE-MSI, National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom.|School of Pharmacy, University of Nottingham , University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: Josephine
authors.initials: J
authors.lastname: Bunch
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Takats
authors.affiliation: NiCE-MSI, National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom.
authors.forename: Ian S
authors.initials: IS
authors.lastname: Gilmore
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis*; D000818:Animals; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D006801:Humans; D008055:Lipids / Q000032:analysis*; D008099:Liver / Q000737:chemistry*; D057054:Molecular Imaging; D021241:Spectrometry, Mass, Electrospray Ionization; D013552:Swine
chemical_list: D008055:Lipids