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Titolo:
DIELECTRIC STACK FILTERS FOR EX-SITU AND IN-SITU UV OPTICAL-FIBER PROBE RAMAN-SPECTROSCOPIC MEASUREMENTS
Autore:
MUNRO CH; PAJCINI V; ASHER SA;
Indirizzi:
UNIV PITTSBURGH,DEPT CHEM PITTSBURGH PA 15260 UNIV PITTSBURGH,DEPT CHEM PITTSBURGH PA 15260
Titolo Testata:
Applied spectroscopy
fascicolo: 11, volume: 51, anno: 1997,
pagine: 1722 - 1729
SICI:
0003-7028(1997)51:11<1722:DSFFEA>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
ULTRAVIOLET RESONANCE RAMAN; POLYCYCLIC AROMATIC-HYDROCARBONS; EXCITED ELECTRONIC STATES; SATURATION SPECTROSCOPY; EXCITATION PROFILES; REJECTION FILTER; LINE REJECTION; DNA; INTERFERENCE; TRYPTOPHAN;
Keywords:
UV RAMAN SPECTROSCOPY; INSTRUMENTATION; DIELECTRIC UV FILTERS; OPTICAL FIBERS; PETN; TNT; DNA; PAH;
Tipo documento:
Article
Natura:
Periodico
Citazioni:
57
Recensione:
Indirizzi per estratti:
Citazione:
C.H. Munro et al., "DIELECTRIC STACK FILTERS FOR EX-SITU AND IN-SITU UV OPTICAL-FIBER PROBE RAMAN-SPECTROSCOPIC MEASUREMENTS", Applied spectroscopy, 51(11), 1997, pp. 1722-1729

Abstract

Dielectric stack interference filters can be used in conjunction witha high-throughput single-stage spectrograph to facilitate the measurement of high signal-to-noise (S/N) ultraviolet (UV) Raman spectra with228.9-nm and 244-nm excitation wavelengths. Placed between the sampleand the spectrograph, these filters reflect Rayleigh scattering whiletransmitting Stokes-shifted Raman scattering. We have measured UV Raman bands from solid, highly scattering samples down to a 290-cm(-1) shift from the Rayleigh line. The high throughput of the filtered single-stage spectrograph enables the measurement of UV Raman spectra from photo-labile samples, including DNA and the energetic materials pentaerythritol tetranitrate (PETN) and trinitrotoluene (TNT), with sufficiently low excitation powers and short accumulation times to minimize photo-alteration. High S/N UV preresonance and resonance Raman are obtained for PETN and TNT within 1 s, indicating the possible application ofUV Raman spectroscopy as a rapid, highly selective screening methodology for the detection of trace levels of contraband explosives. Furthermore, the incorporation of these dielectric filters within a UV optical-fiber Raman probe head provides simultaneous Rayleigh rejection andremoval of background silica Raman scattering. With the use of a 244-nm UV optical-fiber probe, we measured Raman spectra from 100 nM to 10mu M concentrations of polycyclic aromatic hydrocarbon (PAH) in water, even in the presence of an equimolar concentration of the visible fluorophore rhodamine 6G (R6G). Thus, we demonstrate the potential of UVRaman optical-fiber probes for minimally invasive in situ real-time monitoring at low analyte concentrations and within environments in which fluorescence backgrounds would prevent measurements with visible Raman optical-fiber probes.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/10/20 alle ore 09:50:04