In this chapter data about the laser induced fluorescence and Raman spectra
obtained from microvolumetric (some microliters) droplets are introduced when they
are exposed to laser radiation of suitable characteristics in terms of wavelength, power,
and focusing conditions. A comparison is made with the same spectra obtained for the
same solutions and using the same laser beams, except focus characteristics, from
bulky volumes (some milliliters) showing that, basically, the information obtained from
a single droplet after interaction with a single laser beam pulse is the same with that
obtained from the bulky sample. In some cases, function of optimisation degree of the
excitation geometry, the accuracy of spectral data collected from a microdroplet is
higher than for bulk. The equivalence of the spectral data obtained from droplets and
bulk is due to the fact that the interaction takes place in small volumes of the samples
in both cases. In droplet, the remaining solution components that have not interacted
with the pumping laser beam are very few, whereas in bulk their numbers are higher
and so, the radiation emitted at the interaction volume is perturbed by them. This
experimental evidence leads to the recommendation to use in many cases interaction of
laser beams with a single droplet to obtain reliable spectral data, rather than bulky
samples.
Keywords: Chlorpromazine, Dimethyl sulfoxide, Droplet, Hydantoin derivatives,
Laser beam, Laser induced fluorescence, Laser induced phosphorescence, Light
scattering, Luminescence, Microdroplet, Microspectroscopy, Raman, Resonant
interaction, Rhodamine 6G, Spectroscopy, Unresonant interaction.
