HAIR FT-IR MICROSPECTROSCOPY 289 1.5 1.2 - 0.9- 0.6- 0.3 0.0 1800 i I I II 1600 III 14oo 12oo 950. cm-I Figure 2. Typical FT-IR spectrum of human hair (1800-950 cm- • region) is shown. The Amide I, II, and III bands are indicated baseline points relative to the integrated areas of the bands at 1540, 1238, and 1080 cm -• (1475-1495 cm-1, 1300-1185 cm-•, and 1137-997 cm -•, respectively)are also shown. In the ordinate, absolute absorbance values are reported. compare the spectra in this last region, corresponding to the inferior bulb (IB), central bulb (CB) and shaft (S) of the ariagert, catagen, and telogen hairs, we have not reported the Amide II bands (Figure 3). Since major differences were observed in the ! !30-!000 --1 1 cm region, we report in Figure 4 the absorption band at !080 cm- obtained on IB, CB, and S of anagen, catagen, and telogen hairs (Figures 4A, 4C, and 4T) and the corresponding second derivative spectra (Figures 4A', 4C', and 4T'). The bands at !540 --! cm and at !238 cm are attributed to the Amide II and III vibrations of the proteic components. In the Amide III region, the O-P-O asymmetrical vibration of the nucleic acids is also localized. In the bulb portion, the absorptions at !080 cm-! might be assigned to the O-P-O symmetrical vibration of nucleic acids (!4). Some absorptions may be related to certain molecular groups belonging to proteins and nucleic acids, even if a precise assignment is not feasible because of the high molecular complexity of hairs. The second derivatives reported in Figure 4 show similar trends in the shafts of the three

290 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 0.084 0.000 0.179 0.090 O. 168 _ ! o.ooo 14,•o 1300 1 ooo 950 -•'cx- --• o. 148 i•_j o.o74 0.179 --- • 0.099 S• 0.176 .... 0.000 0.234 {/• l•- I 0.000 l__•__ .l 0.088 • EC• i 1480 1300 1000 950 0.229 0.115 0.000 0.157 0.079 0.000 I I 0.196 0.098 0.000 1480 1300 1000 950 Cil1-[ Figure 3. Infrared spectra of anagen (A), catagen (C), and telogen (T) hairs obtained on the inferior bulb region (IB), central bulb region (CB), and shaft (S) (1480-950 cm- • region). In the catagen hair, the _epithelial column (EC) is also reported. In the ordinate, absolute absorbance values are reported.