Comparison of single- and dual-beam configurations for thermal lens spectrometry

Abstract

NaCl were used as samples for the nebulizer/heat chamber. Evidently, small salt crystals were formed from the water droplets passing through the heat chamber. Since the detection limits agree, we conclude the salt crystals were completely vaporized inside the spark and did not significantly alter the nature of the plasma.

Double-beam thermal lens spectrometry

“…Since its development by Whinnery (1)(2)(3)(4)(5), thermal lens techniques have been recognized as useful in the analysis of weakly absorbing species (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). Specifically, the technique has been considered as a detector for chromatography and flow injection analysis (17)(18)(19)(20)(21)(22).…”

Instabilities By Local Heating Below an Interface

“…In particular, it has been applied to the measurement of absorbances and of the concentration of chemical species in liquids [48,49] or in gases [50,51]. These gradients are optically equivalent to a diverging lens, called a thermal lens, leading to an enhancement of the beam divergence.…”

Photothermal Effects in Chemical Analysis

“…Careful comparison has shown that one-and two-beam systems provide essentially identical detection limits (17). A two-beam system is required with pulsed lasers because the laser pulse duration is much shorter than the response time of the thermal lens itself.…”