Fast assay of glucosamine in pharmaceuticals and nutraceuticals by capillary zone electrophoresis with contactless conductivity detection.
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 degrees 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 microm 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 microg/mL; r(2)=0.997) and K(+) (15-75 microg/mL; r(2)=0.997) when using ethanolamine (100 microg/mL) as the internal standard. The LOD values (S/N=3) were 9.3 microg/mL for GlAm and 2.9 microg/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.
Jác
Pavel
P
Department of Analytical Chemistry, Charles University, Heyrovského, Hradec Králové, Czech Republic.
Los
Petr
P
Spácil
Zdenek
Z
Pospísilová
Marie
M
Polásek
Miroslav
M
D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements / Q000032:analysis*; D004553:Electric Conductivity; D019075:Electrophoresis, Capillary / Q000379:methods*; D005944:Glucosamine / Q000032:analysis*; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D004364:Pharmaceutical Preparations; D005944:Glucosamine