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

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).

Iodine‐Azide Detection System for Dipeptides in Thin‐Layer Chromatography

“…The same relationship was observed for free proline. [33] Interferences In general, applying the iodine-azide detection system makes only sulfur (II) compounds visible in chromatograms. However, three groups of additional spots may be found due to certain compounds: 1) iodine-azide reaction inductors (e.g., cysteine or cystine), 2) compounds which react with iodine under experimental conditions (e.g., ascorbic acid), 3) compounds that react with PITC to obtain PTC derivatives (e.g., amino acids).…”

A New Pyrroloquinoline-Derivative-Based Fluorescent Probe for the Selective Detection and Cell Imaging of Lysine

“…Thus, the development of analytical methods for the detection of lysine is of significance for medical and biological research. Some analytical techniques have been used to detect lysine, including colorimetric method [11][12][13][14], liquid chromatography [15] and thin-layer chromatography [16], mass spectrometry [17], luminescent sensors [18], amperometric biosensors [19,20], electrochemical detection [21][22][23][24], and fluorescent probes [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. In these methods, fluorescent probes feature high sensitivity and selectivity-satisfactory capability compared with other complicated methods-having been studied by more researchers.…”

Application of the TLC image analysis technique for the simultaneous quantitative determination of L-proline and L-lysine in dietary supplement

“…For this purpose, phenyl isothiocyanate (PITC) was used, and amino acids were transformed into their phenylthiocarbamyl (PTC) derivatives: PTC-PR and PTC-LY, respectively. The derivatization reaction proceeds as presented in Scheme 2 [10].…”