Laser-induced thermal desorption of aniline from a quartz surface

Voumard, Pierre; Zenobi, Renato; Zhan, Qiao

doi:10.1016/0039-6028(94)90419-7

Cited by 10 publications

(19 citation statements)

References 36 publications

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“…Such processes provide a remarkably versatile method for introducing thermally labile and high molecular weight species intact into the gas phase. The mechanism of laser assisted thermal desorption has been extensively investigated by (Maechling 1995) as well as by Zenobi and coworkers (Voumard et al 1994(Voumard et al , 1995.…”

Section: ^L 2 Ms: Methodologymentioning

confidence: 99%

Microprobe two-step laser mass spectrometry as an analytical tool for meteoritic samples

Clemett

Zare

1997

Symp. - Int. Astron. Union

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Abstract. Microprobe two-step laser mass spectrometry (/iL 2 MS) is a new mass spectrometric method in which the two essential steps of any mass spectrometric analysis, vaporization and ionization, are carried out using two independent laser sources. In the first step, the output of a pulsed infrared laser is focused on the sample to cause rapid heating in the spot area illuminated, which is typically 40 /zm by 40 /im. In the second step, the output of a pulsed ultraviolet laser causes (1+1) resonance-enhanced multiphoton ionization (REMPI) of those desorbed neutral molecules that (1) are able to absorb this UV wavelength and (2) whose ionization potential is less than the energy of two photons of this UV wavelength. The resulting ions are then mass analyzed in a reflectron time-of-flight apparatus. Under suitable conditions fragmentation can be avoided in both the vaporization and ionization steps so that μΙι 2 Μ8 can be applied to the analysis of a mixture of molecules. Applications of ^L 2 MS to meteorite samples are presented as a means of detecting trace amounts of certain organic molecules present in complex materials without prior sample preparation, extraction, purification, and separation steps. Moreover, this analysis can be carried out with micrometer spatial resolution so that in favorable cases the presence or absence of certain molecules can be correlated to mineralogical features of the sample.

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Section: ^L 2 Ms: Methodologymentioning

confidence: 99%

Microprobe two-step laser mass spectrometry as an analytical tool for meteoritic samples

Clemett

Zare

1997

Symp. - Int. Astron. Union

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“…͑b͒ SVFL spectra following irradiation in the T 2 2 band 10 show identical intensities to the 10b 2 2 bands, including the relatively weak cross-sequence bands, confirming the 10b 2 2 assignment for this feature. ͑c͒ We have compared the intensities of 0 0 0 , T 1 1 , and T 2 2 taken from gas-phase spectra 9,10,17,18,19 at room temperature, see Sec. IV D. The ratio of population in these states closely follows a thermal distribution with Tϭ290 K, E(T 1 )Ϸ220 cm Ϫ1 and E(T 2 )Ϸ440 cm Ϫ1 .…”

Section: Vibrational Assignmentmentioning

confidence: 99%

“…15 Laser-induced thermal desorption has numerous applications and has been extensively studied; 16 however, few studies have explored the transfer of energy as desorbed molecules make the transition from surface-bound to gas-phase species. Voumard et al 17,18 and Elokhin et al 19 have demonstrated that internal energy resolved detection of desorbing molecules is a powerful tool for elucidating the laser-induced thermal desorption mechanism. Voumard et al 17,18 have studied the mechanism responsible for intact volatilization of aniline from a quartz surface.…”

Section: Introductionmentioning

confidence: 99%

“…Voumard et al 17,18 and Elokhin et al 19 have demonstrated that internal energy resolved detection of desorbing molecules is a powerful tool for elucidating the laser-induced thermal desorption mechanism. Voumard et al 17,18 have studied the mechanism responsible for intact volatilization of aniline from a quartz surface. They report that aniline molecules leave the dielectric surface with internal energies of 360Ϯ60 K for the vibrational states and 350Ϯ100 K for the rotational contours, well below that of the calculated surface temperature of 500 to 600 K. Their results support a desorption mechanism dominated by a bottleneck in the energy flow from the surface into the adsorbates during laserinduced thermal desorption.…”

Section: Introductionmentioning

confidence: 99%

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Evidence for thermalization of surface-desorbed molecules at heating rates of 108 K/s

Maechling

Clemett

Engelke

et al. 1996

The Journal of Chemical Physics

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Articles you may be interested inOn the mechanism of C60 thin film laserinduced desorption Discharge flowtube studies of O(3 P)+N2H4 reaction: The rate coefficient values over the temperature range 252-423 K and the OH(X 2Π) product yield at 298 K Resonant laser ionization of thorium using continuous thermal heating and pulsed laser evaporation AIP Conf.Laser desorption of aniline-d7 from a single-crystal surface ͑0001͒ of sapphire ͑Al 2 O 3 ͒ at a heating rate on the order of 10 8 K/s was studied using pulsed infrared laser radiation for desorption and resonance enhanced multiphoton ionization ͑REMPI͒ for detection of the desorbed aniline molecules. On the basis of single-vibronic-level fluorescence ͑SVLF͒ spectra we unambigiously assign the 10b transition. REMPI spectroscopy provides vibrational temperatures and therefore describes the internal energy distribution, whereas the time-of-flight ͑TOF͒ profiles provide translational temperatures. All results are consistent with a thermal mechanism for desorption, i.e., pulsed heating of the sapphire surface on the nanosecond time scale leads to thermal desorption and rapid thermalization of the escaping molecules.

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“…With respect to mass spectrometry these studies focused on either direct laser desorption/ionization (LDI) with pulsed infrared (IR) and ultraviolet (UV) lasers, e.g., [7][8][9][10][11][12][13][14][15] or, more relevant for this work, MALDI-MS [5, 16 -28] with pulsed ultraviolet lasers. The first measurements of initial ion velocities in infrared MALDI were reported only very recently by Ermer et al [29].…”

mentioning

confidence: 99%

Measurements of mean initial velocities of analyte and matrix ions in infrared matrix-assisted laser desorption ionization mass spectrometry

Berkenkamp

Menzel

Hillenkamp

et al. 2002

J. Am. Soc. Mass Spectrom.

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The mean initial velocities of analyte ions ranging in molecular weight from 1000 Da to 150 kDa and desorbed with a pulsed Er:YAG laser from various solid-state and liquid IR MALDI matrices were measured along with those of the matrix ions. Experiments with UV MALDI were performed for comparison in addition for a 2,5-dihydroxybenzoic acid preparation. Two different measurement principles were employed, (1) a delayed extraction method, relying on the initial velocity-dependent increase of flight times with delay time between laser and HV ion extraction pulse, and (2) a field-free drift method in which the first region of a two-stage ion source was varied in length and the flight times compared. The two methods yielded somewhat different values for the mean initial ion velocities. Based on a detailed discussion of the measurement principles it is suggested that the actual initial velocities of IR MALDI ions lie between the limits set by the two methods. The influences of the analyte-to-matrix ratio, laser fluence, and laser wavelength on the initial ion velocities were also investigated. Significant differences between the desorption mechanisms for liquid and solid-state matrices were observed. M easurements of the initial kinetic energy of ions and particles form a straightforward approach for investigations on the mechanistics of laser desorption and laser desorption/ionization processes. In time-of-flight (TOF) mass spectrometry, the large and mass-dependent initial kinetic energies of analyte ions in matrix-assisted laser desorption ionization (MALDI), along with a large width in the energy distributions have moreover posed substantial limitations on the instrumental performance for a long time. With state-of-the-art delayed extraction (DE) [1,2] instruments these problems can now partly be overcome [3,4], although sophisticated calibration procedures incorporating explicit initial velocity values are required [5,6]. The determination of the initial velocities of MALDI ions has, therefore, found substantial interest in the last years also from this practical viewpoint.A relatively large number of studies on the kinetic energies of laser desorbed* particles or ions have been performed in the past. With respect to mass spectrometry these studies focused on either direct laser desorption/ionization (LDI) with pulsed infrared (IR) and ultraviolet (UV) lasers, e.g., [7][8][9][10][11][12][13][14][15] or, more relevant for this work, MALDI-MS [5, 16 -28] with pulsed ultraviolet lasers. The first measurements of initial ion velocities in infrared MALDI were reported only very recently by Ermer et al. [29].Different experimental approaches for the determination of initial (ion) velocities have been pursued in these studies. A survey of the employed techniques for UV MALDI has recently been given by Glü ckmann and Karas [17]. Following their classification, the techniques can essentially be arranged into three groups.In the so-called delayed extraction methods (DEM) [5,16,17], the mean initial axial velocity is deduced...

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Laser-induced thermal desorption of aniline from a quartz surface

Cited by 10 publications

References 36 publications

Microprobe two-step laser mass spectrometry as an analytical tool for meteoritic samples

Microprobe two-step laser mass spectrometry as an analytical tool for meteoritic samples

Evidence for thermalization of surface-desorbed molecules at heating rates of 108 K/s

Measurements of mean initial velocities of analyte and matrix ions in infrared matrix-assisted laser desorption ionization mass spectrometry

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