Determination of Glucosamine via Polarimetry

Glucosamine is used as a joint supplement for the treatment of arthralgia and osteoarthritis. In order to have high-quality products the optical rotation of glucosamine needs to be analyzed via polarimetry.

Glucosamine: a special amino sugar

Glucosamine is used for dietary or pharmaceutical purposes. It is taken as a joint supplement for the treatment of arthralgia and osteoarthritis. Most glucosamine is derived from the crustacean polysaccharide chitin. It can be released from chitin by hydrolytic cleavage mediated by boiling in highly concentrated hydrochloric acid for several hours. As glucosamine is a chiral substance, concentration and purity of glucosamine after hydrolyzation or in purchased samples may be determined with polarimetry. The concentration or purity of both glucosamine hydrochloride and glucosamine sulphate can be determined after synthesis and also in quality control. Moreover, international pharmacopoeias such as the US and the European Pharmacopoeia demand the determination of the optical rotation of glucosamine.

MCP polarimeters from Anton Paar

The MCP polarimeters from Anton Paar are ideal for determining the concentration or purity of glucosamine. Depending on the required measurement conditions MCP 100, 200, 300 or 500 can be used.

The MCP polarimeter allows the precise analysis of glucosamine in the milligram range due to the high resolution of up to 0.0001° optical rotation. Peltier temperature control allows temperature control with an accuracy of up to ±0.03 °C which is essential because the optical rotation is temperature-dependent. On top of that, a built-in camera system is available which helps to verify the correct filling of the sample cell in order to avoid air bubbles or smears.

The concentration and purity measurement of glucosamine with polarimetry is further specified in the corresponding Application Note.

Do you have any questions?
Contact Anton Paar directly: info.optotec[at]


Learn more about the MCP Polarimeters

Other relevant instruments

Anton Paar’s process polarimeter Propol can be used for immediate inline and online detection of optical rotation in process applications.

Good to know

The concentration and purity of glucosamine either from crustaceans or after synthesis, can easily be determined with polarimetry