Ion Mobility Spectrometry of Gas-Phase Ions from Laser Ablation of Solids in Air at Ambient Pressure

Abstract

A mobility spectrometer was used to characterize gas-phase ions produced from laser ablation of solids in air at 100 degrees C and at ambient pressure with a beam focused to a diameter of <or=0.2 mm at energy of 6 mJ/pulse and wavelength of 266 nm. Metals, organic polymers, glass, graphite, and boron nitride exhibited characteristic mobility spectra with peaks at drift times between 8.75 and 12.5 ms (reduced mobility values of 2.19 to 1.53 cm(2)/Vs). Ion intensities increased initially and then decreased with repeated laser shots through drilling of the solid, and persistence of signal was proportional to hardness. A single comparatively narrow peak for negative ions was observed in mobility spectra for all materials and this was mass-identified as O(2)(-). These ions were formed in air from reactions of oxygen with electrons emitted from the ablation step. Positive ions ablated directly from the solid were masked in ion mobility spectrometry/mass spectrometry (IMS/MS) studies by ionization of moisture and impurities. Positive ions from solids were seen only in the IMS analyzer at elevated temperature and low moisture. Under such conditions, materials were classified from mobility spectra alone with principal component analysis.

Ion mobility spectrometry coupled with multi-capillary columns for metabolic profiling of human breath

“…For example, the high successful transfer of a laboratory research tool to a hand-held field analyser, developed in 10 000 units and used in battlefield environments [2,3], is unprecedented in the history of analytical instrumentation. There are a lot of activities worldwide associated with the adaptation of IMS to industrial and environmental applications [4][5][6][7][8][9][10][11][12][13]. New developments as the combination of IMS to pre-separation techniques such as gas-chromatographic columns [14][15][16][17][18][19][20][21][22][23] started.…”

Analysis of Bio‐Processes using Ion Mobility Spectrometry

“…Since that time, more than 70,000 ion mobility spectrometers are in use in military and civilian protection procedures and especially at airports for the detection of explosives and illegal drugs. In recent years, ion mobility spectrometry is more and more in use for civilian applications, for example in pharmaceutical [11,12,13], toxicological [14], environmental [15,16], and biological [17,18] fields as well as for structural investigations [19,20].…”

Rapid screening of pesticides from fruit surfaces: preliminary examinations using a laser desorption—differential mobility spectrometry coupling

“…Some experimental set-ups for a coupling of laser desorption and traditional IMS are described in the literature and have been used successfully for the analysis of environmental contaminants and polymers [19,20]. Furthermore, some laboratory devices have been developed for combined laser desorption and ionization using tunable lasers [21,22].…”