TY - JOUR

T1 - Ambient mass spectrometry imaging

T2 - a comparison of desorption ionization by sonic spray and electrospray

AU - Janfelt, Christian

AU - Nørgaard, Asger W

PY - 2012/10

Y1 - 2012/10

N2 - Easy ambient sonic spray ionization (EASI) and desorption electrospray ionization (DESI) were used for imaging of a number of samples, including sections of rat brain and imprints of plant material on porous Teflon. A novel approach termed Displaced Dual-mode Imaging was utilized for the direct comparison of the two methods: Images were recorded with the individual rows alternating between EASI and DESI, yielding a separate image for each technique recorded under perfectly similar conditions on the same sample. EASI works reliably for imaging of all samples, but the choice of spray solvent and flow rate is more critical in tissue imaging with EASI than with DESI. The overall sensitivity of EASI is, in general, slightly lower than that of DESI, and the representation of the dynamic range is different in images of the two techniques for some samples. However, for abundant compounds, EASI works well, resulting in images of similar quality as DESI. EASI can thus be used in imaging experiments where the application of high voltage is impractical or undesirable. The present study is in its nature also a comparison of the characteristics of the two techniques, showing results also applicable for non-imaging work, with regards to sensitivity and experimental conditions.

AB - Easy ambient sonic spray ionization (EASI) and desorption electrospray ionization (DESI) were used for imaging of a number of samples, including sections of rat brain and imprints of plant material on porous Teflon. A novel approach termed Displaced Dual-mode Imaging was utilized for the direct comparison of the two methods: Images were recorded with the individual rows alternating between EASI and DESI, yielding a separate image for each technique recorded under perfectly similar conditions on the same sample. EASI works reliably for imaging of all samples, but the choice of spray solvent and flow rate is more critical in tissue imaging with EASI than with DESI. The overall sensitivity of EASI is, in general, slightly lower than that of DESI, and the representation of the dynamic range is different in images of the two techniques for some samples. However, for abundant compounds, EASI works well, resulting in images of similar quality as DESI. EASI can thus be used in imaging experiments where the application of high voltage is impractical or undesirable. The present study is in its nature also a comparison of the characteristics of the two techniques, showing results also applicable for non-imaging work, with regards to sensitivity and experimental conditions.

KW - Animals

KW - Brain Chemistry

KW - Coloring Agents

KW - Hypericum

KW - Ions

KW - Male

KW - Molecular Imaging

KW - Plant Leaves

KW - Rats

KW - Rats, Sprague-Dawley

KW - Sensitivity and Specificity

KW - Spectrometry, Mass, Electrospray Ionization

U2 - 10.1007/s13361-012-0452-5

DO - 10.1007/s13361-012-0452-5

M3 - Journal article

C2 - 22875334

VL - 23

SP - 1670

EP - 1678

JO - Journal of The American Society for Mass Spectrometry

JF - Journal of The American Society for Mass Spectrometry

SN - 1044-0305

IS - 10

ER -