Study Set Content:
Useful for complex mixtures containing
compounds with widely different absorbance
ranges and for mixtures where peaks overlap
Diode Array Detector (DA)
Detection is based on the scattering of a beam of
light by particles of compound remaining after
evaporation of the mobile phase
Evaporating light-scattering detector
(ELSD)
Usually used in the coulometric mode.
Electrochemical detector
No distinction between this detector and an
electrochemical detector except that that the
detector has arisen largely as part of ion
chromatography and tends to be used in the
amperometric mode, where conduction of current
between two electrodes by an ionic analyte is
measured rather than current changes resulting
from oxidation or reduction of the analyte.
5. Pulsed Amperometric detector
Detections is based on production of electrons
when the analyte is oxidised, which is the more
common mode of operation, or consumption of
electrons in the reductive mode.
4. Electrochemical detector
Detection is based on changes of refractive index
when the analyte passes through the sample cell in
the detector, the reference cell being filled with
the mobile phase.
6. Refractive Index detector (IR)
Typical pharmaceutical applications include the
analysis of cardenolides and aminoglycoside
antibiotics which do not have chromophores.
5. Pulsed Amperometric detector
Like the ELSD, the RI detector is a universal
detector with even less selectivity than the ELSD.
6. Refractive Index detector (IR)
It is a universal detector like RI and ELSD
detectors but is much more sensitive than these
detectors.
Corona charged aerosol detector (CAD)
Detection is based on fluorescent emission
following excitation of a fluorescent compound at
an appropriate wavelength.
7. Fluorescence detector
A robust and selective detector applicable to
compounds exhibiting fluorescence and to
fluorescent derivatives.
7. Fluorescence detector
Detection is based on nebulisation of the HPLC
eluent and then the nebulised analyte particles
pass a platinum corona discharge pin which
imparts a positive electrostatic charge to them.
8. Corona charged aerosol detector (CAD)
Most useful for selective bioanalyses.
7. Fluorescence detector
Easily () and precise sample introduction ensures quantitative precision
controlled
is the chromatographic technique which has seen the most intensive development in recent
years, leading to improved columns detectors and software control
HPLC
The variety of columns and detectors means that the selectivity of the method can be readily
adjusted.
Compared to gas chromatography (GC) there is () risk of sample degradation because heating is
not required in the chromatographic process.
less
It is readily
automated
With the advent of () methods can be very rapid
UPLC
There is still requirement for reliable and inexpensive detectors which can monitor compounds
that lack a
chromophore
