Multivariate Method Based on Raman Spectroscopy for Quantification of Dipyrone in Oral Solutions

Table 1

Assignments of the main Raman bands of dipyrone found in Figure 3 based on the literature of vibrational spectroscopy.

Peak position (cm^−1)	Assignment
563	SO2 scissor deformation (sulfone) [37]
600–700	Ring in-plane and out-of-plane deformations (phenyl group)
740–790	C-H out-of-plane bending (phenyl group) [38]
1003	C=C stretching and angular CCC in-plane ring deformation (symmetric stretching—“breathing” of the phenyl ring) [37, 39]
1100	SO2 symmetric stretch (sulfone) [37]
1359	SO2 antisymmetric stretch (sulfone) [37]
1459	C=C ring stretching (degenerate vibrations pair of the phenyl ring, associated to the symmetric out-of-phase and antisymmetric stretching of the two triatomic systems); N-CH3 deformation (amine) [38, 40]
1495
1601	C=O and C=C stretching (phenyl group); HCH deformation (CH3 an CH2 groups) [39]