Application of the iodine-azide reagent for selective detection of thiophosphoryl compounds in thin-layer chromatography

Thin Layer Chromatography with Post-Chromatographic Iodine-Azide Reaction for Thiuram Analysis in Food Samples

“…The non-improved method involving the iodine-azide reaction was based on spraying the plates with a mixture of sodium azide and iodine solution (in potassium iodide solution). [10,[17][18][19] As a result, white spots on a yellow background appeared. However, it was observed that the excess of iodine made the white spots vanish and consequently, it was the reason for the greatly increased detection limits.…”

“…Detection with the Non-improved Iodine-azide Procedure (Non-improved I 2 À N À 3 ) [19] After drying, the developed plates were sprayed with a freshly prepared mixture of sodium azide, iodine, and potassium iodide solution. Due to the catalytic effect of the C=S bound, the spots which were read after two minutes, became visible as white spots on a yellow background and they were stable for several minutes.…”

“…The hampering effect of the iodide ions in the iodine-azide reaction induced by many thiols or organothiophosphorus compounds is intensified with increasing iodide ions concentration. [19][20][21][22] An increase of potassium iodide concentration stimulates an increase of iodine consumption in the iodine-azide reaction induced by many thiols and an increase of induction time. We investigated the influence of iodine ions on the detection limits obtained with the improved iodine-azide procedure (Table 1).…”

Detection of mercaptopyridines and mercaptopyrimidines in planar chromatography with iodine–azide reaction as a detection system

“…The method involving iodine-azide reaction was based on spraying the plates with a mixture of sodium azide and iodine solution (in potassium iodide solution) [20]. As a result, white spots on a yellow background appeared.…”

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

“…Ninhydrin reagent: 0.15 g ninhydrin was dissolved in 1.5 mL glacial acetic acid and diluted to 50 mL with n-butanol. Non-modified iodine-azide reagent: 10 mL of 1 M sodium azide solution adjusted to pH 5.5 was added to 10 mL of 1 M iodine (in 1 M potassium iodide [4]). Phosphate, borate, and Britton-Robinson buffers (0.01 M) were used.…”