QUANTIFICATION OF LYSINE IN DIETARY SUPPLEMENT TABLETS AND CAPSULES BY REVERSED PHASE HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHY WITH VISIBLE MODE DENSITOMETRY

ABSTRACT

A quantitative method using chemically bonded C-18 silica gel HPTLC plates, automated bandwise sample application, detection with ninhydrin chromogenic reagent solution, and automated visible mode densitometry has been developed for the determination of L-lysine hydrochloride in nutrition supplements. Three products containing 500 mg of lysine and additional ingredients were analyzed. Accuracy was validated by analysis of spiked blank and standard addition samples and precision by performing replicated analyses. Accuracy was found to be within 3% of the theoretical values, and precision was 2% relative standard deviation.

Keywords:

• Thin layer chromatography
• Densitometry
• Amino acid
• Lysine
• Nutrition supplements

ACKNOWLEDGMENT

Janna Pachuski was supported by a Camille and Henry Dreyfus Foundation Senior Scientist Initiative Grant awarded to Professor Joseph Sherma.