Glucosamine: Testing of glucosamine raw material
and simple formulas can be done by HPLC with EC
(Electrochemical) or UV detection at 195-200nm wavelength:
- UV detection--As any experienced chromatographer
knows, at this low wavelength the method could
face challenging interference and high background
noise. If your contract laboratory uses UV detection
for glucosamine testing, you need to double-check
the reliability of reported results.
- EC detection-The required experience in proper
care/operation of an EC detector and narrow
application of this technique could make this
assay a relatively unaffordable one in many
laboratories. In addition, the Redox reaction
on an electrode surface can be very complicated
and irreproducible. It is much less rugged than
a UV detector in general.
Testing of a wide variety of glucosamine products,
especially complex formulas or low levels of glucosamine
(as low as <0.1%, w/w), a pre-column derivatization
HPLC method used at Analytical Laboratories In
Anaheim, Inc. has been extremely efficient, sensitive
- Pre-column derivatization HPLC-Method has
been used in testing raw materials, dosage forms
and animal feed containing trace levels glucosamine.
The principle of this validated method: the
lack of chromophores in glucosamine is overcome
by forming an adduct that gives UV absorption
at a higher wavelength range 240-260 nm. This
reduces background noise and interference, and
increases the signal to noise level tremendously.
In addition, the derivative increases the retention
of glucosamine with a reversed-phase HPLC system.
(See chromatograms below.)
Fig. 1. (A) standard at 15.0 ppm concentration,
(B) a feed sample at 0.11% trace level