An assessment of the laser microprobe analyzer as a tool for quantitative analysis in atomic emission spectrometry

Laser-enhanced ionization as a diagnostic tool in laser-generated plumes

“…To date, most methods for resolution of catalysts have relied on fixed-time, single-point determinations of activity in which catalysts are differentiated by extents of inhibition rather than by inhibition rate constants. Multipoint methods, however, reduce errors due to variability in rate constants (6), produce statistics which can be used to detect model errors (7), and provide data for the determination of three or more catalysts from a single set of kinetic data (8). The last advantage is particularly significant because single-point, fixed-time methods require measurements for the same number of different conditions as there are catalysts to be resolved.…”

“…With the use of different power and wavelength conditions, neutral particles (such as atoms, clusters, and molecules) and ions can be generated in the laser plasma. However, laser microprobe analysis still remains a qualitative or semiquantitative method (3,7) due to the uncertainties arising from the laser power fluctuations, matrix effects, surface conditions, and focusing conditions. Since the amount of material produced by the laser vaporization process depends on the pulse-to-pulse laser power stability (most modern pulsed lasers provide <5% fluctuation), a large error can still be obtained by normalizing the amount of material evaporated to the laser power (8,9).…”

“…Since the amount of material produced by the laser vaporization process depends on the pulse-to-pulse laser power stability (most modern pulsed lasers provide <5% fluctuation), a large error can still be obtained by normalizing the amount of material evaporated to the laser power (8,9). The matrix effects (7,(10)(11)(12) caused by the different physical and chemical properties provide different environments for the vaporization process in which different temperatures and excitation processes can occur. In addition, the local power density resulting from different focusing conditions and incidence angles is difficult to control and measure.…”

Continuous Wave Diode Laser Total Solid Sample Vaporization For Biological Sample Analysis—Lead in Bovine Liver

“…In the power density range from 10 4 to 10 7 W cm 02 , the resulting vapor consists of polyatomic particles and molecular species (24). The relatively low power density used in this work probably gave rise to droplets and clusters (41). To improve the analytical performance, at least an order of magnitude increase in the laser power density would be needed to ensure a complete vaporization and well controlled particle size.…”

The laser as an analytical probe in glow discharge mass spectrometry

“…The laser atomization process has been employed for direct solid sample introduction in a variety of excitation and ionization sources, including ICP emission [3,4], arc/spark emission [5,6], direct current plasma sources (DCP) [7], and ICP mass spectrometry [8]. The laser has also been used as a direct source for atomic emission [6,9] and ablated neutral atoms have permitted atomic absorption analyses [10,11].…”