[lab] qualitative color reactions Flashcards
tests for identification of specific functional group
(FANSPHXBNM)
fohl’s
amide
ninhydrin
sakaguchi
pauly’s
hopkins cole
xanthoproteic
biuret
nitroprusside
millon’s
test to detect the presence of peptide bonds
biuret test
reagents of biuret test
NaOH & CuSO4
positive result of biuret test
pink to violet to blue coloration
principle of biuret test
complexation of Cu2+ with a peptide bond
test to detect free a-amino acids and amine
ninhydrin test
reagents of ninhydrin test
1, 2, 3-indanetrione monohydrate / triketohydrindene & EtOH
positive result of ninhydrin test
blue to blue-purple or yellow-orange
principle of ninhydrin test
oxidative decarboxylation & deamination followed by condensation
test to detect aromatic amino acids (WYF)
xanthoproteic test
reagents of xanthoproteic test
concentrated HNO3 & concentrated NaOH
positive result of xanthoproteic test
yellow solution (heating); orange solution (excess NaOH)
principle of xanthoproteic test
nitration of aromatic ring
test to detect phenolic group in tyrosine
millon’s test
reagents of millon’s test
HgSO4 in H2SO4
positive result of millon’s test
old rose / flesh / purple-red precipitate
test to detect indole group in tryptophan (W)
hopkins cole test
principle of millon’s test
complexation (mercuration & nitration or nitrosation / complexation of nitrohydroxyphenyl derivatives with Hg2+)
reagents of hopkins cole test
glyoxylic acid & concentrated H2SO4
positive result of hopkins cole test
pink to violet interface
principle of hopkins cole test
reduction of oxalate to glyoxylate and acid-catalyzed
test to detect the presence of guanido group of arginine
sakaguchi test
positive result of sakaguchi test
red to red-orange color
reagents of sakaguchi test
a-naphthol, NaOBr, NaOH & urea
