• 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 and reliable:

• 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.)