Molecular imaging by Mid-IR laser ablation mass spectrometry

Vertes, Akos; Nemes, Péter; Shrestha, Bindesh; Barton, Alexis A.; Chen, Zhaoyang; Li, Yue

doi:10.1007/s00339-008-4750-5

Cited by 48 publications

(46 citation statements)

References 29 publications

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“…Under these conditions the IR laser pulse produces gaseous analyte ions via ablation of charged droplets which then fission by an ESI-like ionization mechanism 16,17. However, we have found that the post-ionization using ESI generally provided greater sensitivity, consistent with other studies 18. Accordingly, the results presented here employed solely the orthogonal ESI sampling approach.…”

Section: Resultssupporting

confidence: 81%

Single Droplet Separations and Surface Partition Coefficient Measurements Using Laser Ablation Mass Spectrometry

Jorabchi

Smith

2009

Anal. Chem.

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Surface activity of analytes plays a significant role in many chemical and physical phenomena. We present here a mass spectrometric method to characterize surface activity and solute partitioning between bulk liquid and the gas-liquid interface in droplets. The approach employs ablation by an IR laser from the surface of a microliter droplet deposited on a stainless steel post. The ablated material is ionized for mass spectrometric analysis by either droplet charging or by post-ionization in an electrospray plume. Three areas of application have been explored using this method; 1) separations in a single droplet: continuous ablation by a series of many successive laser pulses results in faster depletion of more surface active analytes, effectively comprising a surface activity-based separation. 2) Partition coefficient measurements: droplet volume is held constant during ablation by continually replenishing lost solvent. This leads to analyte-specific ion signal decay curves that may be fitted to a model based on Langmuir adsorption isotherms and simple analytical expressions, yielding quantitative values for the analyte surface partition coefficients. 3) Studies of the relationship between surface partitioning and HPLC phase partitioning: comparisons of surface activities measured by laser desorption with retention times in reversed phase HPLC reveal that the relationship between the two partitioning processes is very sensitive to chemical structure. Poor correlation between the retention time and surface activity is also observed within a subcategory of analytes (peptides). This effect is attributed to multi-modal solute-stationary phase interactions. The laser desorption approach presented here provides direct information on analyte surface activities free from the complications encountered in chromatographic methods due to chemical structure variations.

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Section: Resultssupporting

confidence: 81%

Single Droplet Separations and Surface Partition Coefficient Measurements Using Laser Ablation Mass Spectrometry

Jorabchi

Smith

2009

Anal. Chem.

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“…Ejected biomolecules coalesce with charged droplets formed from an electrospray source, and a portion of them is converted into gas-phase ions for introduction into a mass analyzer [65]. For MSI experiments, the sample holder is mounted on a motorized positioning stage and scans the target in the x–y plane while a manual translation stage positions the holder in the z-direction for signal optimization [66]. Once again, spectra are taken for each pixel on the sample surface.…”

Section: Methodological Developmentsmentioning

confidence: 99%

From Pixel to Voxel: A Deeper View of Biological Tissue by 3D Mass Spectral Imaging

Greer

2011

Bioanalysis

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Three dimensional mass spectral imaging (3D MSI) is an exciting field that grants the ability to study a broad mass range of molecular species ranging from small molecules to large proteins by creating lateral and vertical distribution maps of select compounds. Although the general premise behind 3D MSI is simple, factors such as choice of ionization method, sample handling, software considerations and many others must be taken into account for the successful design of a 3D MSI experiment. This review provides a brief overview of ionization methods, sample preparation, software types and technological advancements driving 3D MSI research of a wide range of low- to high-mass analytes. Future perspectives in this field are also provided to conclude that the positive and promises ever-growing applications in the biomedical field with continuous developments of this powerful analytical tool.

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“…Matrices must absorb light at the laser wavelength and must not react with tissue-bound analyte. Imaging with an infrared laser ( IR-MALDI-MSI ) allows one to use water as a matrix due to high absorptivity in the mid-IR range [47]. Water can also be added for IR laser ablation by freezing the tissue to form a thin layer of frost, as shown by Muddiman and coworkers [48].…”

Section: Mass Spectrometry Imaging Fundamentalsmentioning

confidence: 99%

Qualitative and quantitative mass spectrometry imaging of drugs and metabolites

Lietz

Gemperline

2013

Advanced Drug Delivery Reviews

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Mass spectrometric imaging (MSI) has rapidly increased its presence in the pharmaceutical sciences. While quantitative whole-body autoradiography and microautoradiography are the traditional techniques for molecular imaging of drug delivery and metabolism, MSI provides advantageous specificity that can distinguish the parent drug from metabolites and modified endogenous molecules. This review begins with the fundamentals of MSI sample preparation/ionization, and then moves on to both qualitative and quantitative applications with special emphasis on drug discovery and delivery. Cutting-edge investigations on sub-cellular imaging and endogenous signaling peptides are also highlighted, followed by perspectives on emerging technology and the path for MSI to become a routine analysis technique.

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Molecular imaging by Mid-IR laser ablation mass spectrometry

Cited by 48 publications

References 29 publications

Single Droplet Separations and Surface Partition Coefficient Measurements Using Laser Ablation Mass Spectrometry

Single Droplet Separations and Surface Partition Coefficient Measurements Using Laser Ablation Mass Spectrometry

From Pixel to Voxel: A Deeper View of Biological Tissue by 3D Mass Spectral Imaging

Qualitative and quantitative mass spectrometry imaging of drugs and metabolites

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