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Klarite in analytical chemistry
Surface enhanced Raman Spectroscopy (SERS) is
a powerful and versatile tool for both qualitative and quantitative
chemical analysis.
Qualitative analysis
SERS provides valuable information on the molecular structure of
chemical compounds. Like other vibrational spectroscopic techniques
such as FTIR and Raman, SERS spectra provide a distinctive fingerprint
of bands. The position (wavenumber) and relative intensities of
these bands are determined by the functional groups present in the
molecules as well as the molecular geometry.
Applications of these capabilities include:
- Investigating the molecular structure
of novel compounds
- Determining the chirality of enantiomeric
molecules
- Identifying unknown or suspect samples
using the entire spectrum as a fingerprint
- Verifying a known material’s composition
by comparing its spectrum with those from a calibration set
Quantitative analysis
The intensity of the bands in SERS spectra is directly related to
the quantity of sample being measured. This allows SERS to be used
to quantify single analytes as well as multicomponent mixtures.
For simple mixtures, individual or combined band intensities can
be used to quantify components directly.
For more complex mixtures, or for samples with overlapping bands,
whole-spectrum chemometric techniques such as partial least squares
(PLS) are more reliable.
The sensitivity of SERS lends itself to analysing very low levels
of analyte.
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