Study Set Content:
A moderately polar phase applicable to the
analysis of surfactants. Some of its selectivity is
due to dipole–dipole interactions
6. Cyanopropyl Silica Gel
Usually based on ion pairing of the analyte with
quaternary ammonium groups on the surface of
the stationary phase. Useful for the separation of
polar compounds with anionic groups such as
nucleotides and anionic drug metabolites such as
sulphates or glucuronides
8. Strong anion exchanger (SAX)
Useful for analysis of very polar compounds such
as aminoglycosides and other charged sugar
molecules and polar bases such as catecholamines
7. Strong cation exchanger (SCX)
Measure absorbance of
light
Spectrophotometer
Electrochemically
measures
oxidized/reduce analyte
Electrochemical
Detectors
Measures fluorescence
Fluorometers
Measures change in
refractive index
Refractometer
Detects ions after
separation by mass-to-
charge ratio
Mass spectrometer
Spectrophotometer
Pg to ng
Electrochemical
Detectors and Fluorometers
1 microgram
Refractometer
Fg to ng
Mass spectrometer
Analyte must absorb
UV or visible light
Spectrophotometer
Useful for
catecholamines
Electrochemical
Detectors
Analyte must
fluoresence
Fluorometers
Detection of most
compounds but
relatively low
sensitivity
Refractometer
Analyte must be
converted to ionized
form
Mass spectrometer
A robust detector with good sensitivity works
approximately in the range 0.01-100 mcg of a
compound on-column.
1. Variable wavelength UV Detector
An advanced type of UV detector with the ability
to monitor across the full UV range
simultaneously, using an array of photodiodes
which detect light dispersed by a fixed
monochromator over a range of wavelengths,
offering a resolution of ca 1nm.
2. Diode Array Detector (DA)
Based on the absorption of UV light by an
analyte.
Variable wavelength UV Detector
