Detection of proline, arginine, and lysine using iodine-azide reaction in TLC and HPTLC

✍ Scribed by Robert Zakrzewski; Witold Ciesielski; Dorota Kaźmierczak

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 128 KB
• Volume: 26
• Category: Article
• ISSN: 1615-9306
• DOI: 10.1002/jssc.200301452

✦ Synopsis

Abstract

The application of a modified iodine‐azide procedure for the detection of proline, arginine, and lysine is described. Phenyl isothiocyanate was used to transform amino acids into phenyl thiocarbamyl derivatives (derivatization in situ). The developed plates were sprayed with a mixture of sodium azide and starch solution, adjusted to pH 5.5, and exposed to iodine vapour. Due to the catalytic effect of the CS bond, the spots appeared white on a violet‐grey background and were stable for 20 minutes. The detection limits were found to lie in the pmole range. The iodine‐azide test is compared with other procedures (iodine, UV, ninhydrin).