Chemical Analysis of Microscopic Fluorescent Materials by Dispersive 1064 Raman System - - Spectroscopy
 Home   Mass Spectrometry   ICP-MS   Infrared   FT-IR   UV-Vis   Raman   NMR   X-Ray   Fluorescence  
Home
Magazine
Issue Archive
Subscribe/Renew
Special Issues
Reprints
The Application Notebook
Current Issue
Archive
Submission Guidelines
Training
SpecAcademy
E-solutions
Digital Edition
Subscribe to the Digital Edition
The Wavelength
Subcribe to The Wavelength
Subscribe to the MS E-news
Resources
Market Profiles
Information for Authors
SpecTube
Webcasts
Advertiser services
Contact Us
Columns
Atomic Perspectives
Chemometrics in Spectroscopy
Focus on Quality
Laser and Optics Interface
Mass Spectrometry Forum
The Baseline
Molecular Spectroscopy Workbench

Chemical Analysis of Microscopic Fluorescent Materials by Dispersive 1064 Raman System

Raman measurement on microscopic inclusions in fluorescent materials requires the ability to measure in small volumes, excellent throughput, and long wavelength excitation such as 1064 nm for fluorescence reduction. Carotenoids and keratin can be measured in epoxy and fossil amber by BaySpec's dispersive 1064 confocal Raman microscope.

Inclusions, small particles less than 1 mm in diameter embedded in other materials, are of interest in a number of different areas. In some manufactured products they result in cosmetic, structural, or chemical resistance defects. On the other hand, entrapped inclusions in paleology, or paints and stains in artefacts are a time-capsule from our past. This article demonstrates a few examples of fast, nondestructive identification of microscopic fluorescent samples using Raman spectroscopy, which were previously unattainable.


Figure 1: 1064 nm Raman spectra of feathers from an extinct pink-headed duck and from a flamingo wing. Courtesy of Dr. Daniel Thomas, Smithsonian Institution. Refer to reference 1 for Raman spectra of feathers in fossil amber. Raman Data were taken by BaySpec’s Nomadic™ 1064 nm Raman microscope.
The challenge for Raman spectroscopy in the past was that it was susceptible to fluorescence. Working with 1064 nm wavelength lasers avoids fluorescence, by avoiding exciting the electronic transitions. Traditionally, due to grating and detector limitations, 1064 nm Raman is often obtained by an FT-Raman system, which is very slow because each spectrum is composed by constantly moving interferometers. Sample mapping using an FT-Raman system is almost impossible. With recent advances in gratings and InGaAs detectors, volume mapping, depth and surface profiling can be accomplished easily with BaySpec's Raman system. For instance, a 1064 nm Raman microscope in dispersive configuration with f2 high-throughput Raman spectrometer is able to create a chemical image as fast as a traditional Raman microscope with visible lasers such as 532 nm. Furthermore, such dispersive configuration allows great flexibility of the system, such as a high-magnification video probe being added to the system to measure the area of interest quickly on samples that do not fit under a microscope.


Figure 2: Painting’s cross-section and spectra of the different layers using a Raman video microprobe attached to a BaySpec RamSpec™ 1064 nm Raman spectrometer.
Microscopic feathers can occasionally be found embedded in fossil amber, which hold clues about the prehistoric animals. The technique was successfully applied to fossil feathers by using BaySpec's Nomadic™ 1064 nm Raman microscope (Figure 1) (1). The versatility of the video probe in being able to make measurements of areas and depth of a painting is unmatched (Figure 2). In a quick summary, Raman imaging using 1064 nm excitation provides a unique and rapid ability to chemically profile inclusions with fluorescence.

Reference

(1) D.B. Thomas, P.C. Nascimbene, C.J. Dove, D.A. Grimaldi, and H.F. James, Sci. Rep. 4, 5226 (2014).

BaySpec, Inc.
1101 McKay Drive, San Jose, CA 95131
tel. (408) 512-5928
Website: http://www.bayspec.com/

Rate This Article
Your original vote has been tallied and is included in the ratings results.
View our top pages
Average rating for this page is: 0
Headlines from LCGC North America and Chromatography Online
Maintaining Precision During Method Transfer
FMS NA - Automated SPE and Cleanup for PCBs in Human Serum
FMS EU - Automated SPE and Cleanup for PCBs in Human Serum
Why Laboratories should adopt TYPE-C™ Technology
UCT NA - Free Opiates and Glucuronides in Urine Extracted by Clean Screen® DAU and Analyzed by LC-MS/MS
Source: Application Notebook,
Click here