Occurrence of Ninhydrin-Positive Carbohydrates in Thin-Layer Chromatograms of Urinary Amino Acids

Abstract

Glucose and other carbohydrates may appear as ninhydrin-positive compounds in thin-layer chromatograms of urinary amino acids. Positions and colours of the carbohydrates are described and discussed in relation to possible ‘false’ positive reactions in determinations of amino acids, primary amines, and amino sugars.

Key Words:

• Amino acids
• urine
• fructose
• galactose
• glucose
• lactose
• mannose
• ninhydrin-positive compounds
• ribose
• thin-layer chromatography
• xylose