Application of iodine-azide reaction for detection of amino acids in thin-layer chromatography.
The iodine-azide reaction was employed to TLC detection of sulphur-containing derivatives of protein and some non-protein amino acids. The derivatization reaction with phenyl isothiocyanate (PITC) took place directly on the plate before the developing step. Subsequently, the plates were sprayed with a mixture of sodium azide and starch solution in NP-TLC and in the case of RP-TLC sodium azide solution with starch incorporated into mobile phase and then exposed to iodine vapour. The spots became visible as white spots on violet-grey background. The obtained detection limits of PTC-derivatives have been compared with other visualizing techniques commonly used in TLC practice (UV254 and iodine vapour). The iodine-azide system has been proved to be the most favourable and enabled to detect quantities per spot in the range of 1-60 pmol (HPTLC) and 3-100 pmol (TLC).
Kaźmierczak
Dorota
D
Department of Instrumental Analysis, University of Lódź, Pomorska 163, 90-236 Lódź, Poland.
Ciesielski
Witold
W
Zakrzewski
Robert
R
Zuber
Monika
M
D000596:Amino Acids / Q000032:analysis*; D001386:Azides / Q000737:chemistry*; D002855:Chromatography, Thin Layer / Q000379:methods*; D007455:Iodine / Q000737:chemistry*
D000596:Amino Acids; D001386:Azides; D007455:Iodine