Fast assay of glucosamine in pharmaceuticals and nutraceuticals by capillary zone electrophoresis with contactless conductivity detection

✍ Scribed by Pavel Jáč; Petr Los; Zdeněk Spáčil; Marie Pospíšilová; Miroslav Polášek

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 152 KB
• Volume: 29
• Category: Article
• ISSN: 0173-0835
• DOI: 10.1002/elps.200800068

✦ Synopsis

Abstract

A novel capillary electrophoresis (CE) method with contactless conductivity detection suitable for the determination of glucosamine (GlAm) and K^+^ in pharmaceuticals was devised. Under the optimum conditions (aqueous 30 mM acetate buffer of pH 5.2 as the background electrolyte; voltage 30 kV; 25°C), GlAm (migrating as glucosaminium cation) was well separated from K^+^ that could occur in the dosage forms as excipient. The CE analysis was performed in fused‐silica capillaries (50 µm i.d., 75 cm total length, 27 cm to detector) and the separation took <3 min. The calibration graphs were linear for both GlAm (100–300 µg/mL; r^2^=0.997) and K^+^ (15–75 µg/mL; r^2^=0.997) when using ethanolamine (100 µg/mL) as the internal standard. The LOD values (S/N=3) were 9.3 µg/mL for GlAm and 2.9 µg/mL for K^+^. The method was applied to the assay of GlAm content in various dosage forms. Intermediate precision evaluated by determining the content of GlAm in a single formulation on 3 consecutive days was characterized by RSD 2.35% (n=15). Acceptable accuracy of the CE method was confirmed by the added/found GlAm recovery experiments (recoveries 94.6–103.3%) and by statistical comparison of the results attained by the proposed CE and a reference HPLC method.