Laser diode thermal desorption

Edge, T., Smith, C., Hill, S., Picard, P., Letarte, S., Wilson, I. D., and Vince, P. (2008). Comparison of laser diode thermal desorption (LDTD) source vs LC-MS for the analysis of a theraputic drug in biological extracts. In Proceedings of the 56th ASMS Conference on Mass Spectrometry and Allied Topics. ASMS, Denver, CO. 

Wu, J. et al., High-throughput cytochrome P450 inhibition assays using laser diode thermal desorption-atmospheric pressure chemical ionization-tandem mass spectrometry, Anal. Chem., 79, 4657, 2007. 

Another emerging technique in this area is laser diode thermal desorption (LDTD), which is used along with a commercially available APCI source to rapidly introduce a large number of samples into the MS without LC separation. With LDTD, samples are adsorbed onto the surface of a well in a >96-well plate. An IR laser beam is then used to vaporize the material in each well into... 

LC/MS/MS Liquid chromatography coupled with a triple-quadrupole mass spectrometer operated in MRM mode LDTD Laser diode thermal desorption... 

Abbreviations AOD, Acousto-optical deflection BCB, bisbenzyocyclobutadiene CCD, indirect contact conductivity detection CL, chemiluminescence ECD, electron capture detector FCS, fluorescence correlation spectroscopy FRET, fluorescence resonance energy transfer ICCD, integrated contact conductivity detection GMR, giant magnetoresistive LED-CFD, light emitting diode confocal fluorescence detector LIF, laser-induced fluorescence LOD, limit of detection MALDI, matrix-assisted laser desorption ionization PDMS, poly(dimethylsiloxane) PMMA, poly(methylmetha-crylate) SPR, surface plasmon resonance SVD, sinusoidal voltammetric detection TLS, thermal lens spectroscopy. 

Laser desorption atmospheric pressure chemical ionization (LD-APCI) combines a laser system and an APCI source to desorb and ionize small chemical compounds on TLC plates (Figure 7.3) [29]. Vaporization and desorption of analytes from the TLC gel bed was achieved by surface heating with a continuous wave (CW) diode laser operated at 808 nm. It was reported that a laser power density of 10 W/cm enables desorption of analytes from white TLC plates. Furthermore, the application of a graphite suspension (10 mg/mL in isopropanol) on the TLC gel decreased the CW laser power required for analyte desorption to 10" W/cm. Thermally desorbed analytes were postionized by reacting with charged species generated by corona discharge of the air. The TLC LD-APCI/MS approach was first used to characterize... 

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