UV resonance Raman spectroscopy using a quasi–continuous—wave laser developed as an industrial analytical technique

Abstract

A resonance Raman method was developed for the study of a wide range of materials possessing UV chromophores with high sensitivity. The experimental arrangement, utilizing a low peak power yet high average power quasicontinuous-wave laser source, permits the study of both liquid and, for the first time, solid samples. Evidence for laser-induced sample degradation was observed from low levels of solid polycyclic aromatics dispersed in potassium chloride, but this was largely overcome by sample spinning. In addition, it was found that the Raman spectrum of individual components in a complex mixture can be selectively enhanced by a judicious choice of laser wavelength. Polyethylene and poly(viny1 chloride) were investigated and evidence for unsaturation was detected from both systems. This is attributed to the resonance enhancement of unsaturated moieties contained within the polymer.

Ultraviolet R aman Spectrometry

“…An alternative approach uses a modelocked Nd : YAG laser to create a quasi-continuous wave (CW) UV source with a duty cycle of 0.01. 19,20 A new tunable quasi-CW UV laser source has been demonstrated that utilizes a titanium sapphire laser that is frequency quadrupled to generate light tunable from 205 to 230 nm. 21 True CW UV laser excitation can now be obtained by intracavity doubling of Ar and Kr lasers.…”

UV resonance Raman spectroscopy for analytical, physical, and biophysical chemistry. Part 1

“…An alternative approach uses a mode-locked Nd:YAG laser to create a quasi-continuous wave UV source with a duty cycle of 0.01 (14). A new laser has just become available that is ideal for Raman measurements that do not require continuous tuning (15).…”

Surface-Sensitive Molecular Information on Polymers from UV-Resonance Raman Spectroscopy

“…In this contribution we report on the anticipated feasibility of using UV-resonance Raman spectroscopy (UV-RRS) in the study of polymeric samples. UV-RRS is comm only used in biological studies, 4 but it has also been applied to probe polymers [5][6][7] and aromatic compounds. [8][9][10] RRS works under the condition that the excitation wavelength lies within an absorption band of the sample.…”