The use of visible absorption spectra to evaluate different color reactions for the detection of cyclic ureides.
Modifications of the Zwikker- and Parri color detection tests were investigated and compared according to their ability to distinguish between nine different barbituric acids and hydantoins. Solutions of the resulting complexes in 50% DMSO were analyzed spectrophotometrically. 350 spectra have been analyzed and criteria for their assessment have been defined. The evaluation based upon the occurrence of a peak in the visible absorption spectra, in comparison with the spectrum of the blank solution. The results were in accordance to those obtained in the visual assessment using a color palette formerly introduced. Cobalt(II) nitrate and methanolic solution of piperidine, or cyclohexylamine, respectively, were the suitable components to get unmistakable results.
Meusel
M
M
Pharmaceutical institute, University of Bonn, Bonn, Germany.
Frizler
M
M
Ottersbach
P
P
Peters
L
L
Gütschow
M
M
D000588:Amines / Q000737:chemistry; D003116:Color; D003124:Colorimetry; D004121:Dimethyl Sulfoxide; D007202:Indicators and Reagents; D015203:Reproducibility of Results; D013053:Spectrophotometry; D014508:Urea / Q000031:analogs & derivatives* / Q000032:analysis*
D000588:Amines; D007202:Indicators and Reagents; D014508:Urea; D004121:Dimethyl Sulfoxide