Beauty Care Laboratory, Kracie Home Products, Ltd., 134 Goudocho, Hodogaya, Yokohama, Kanagawa, 240-0005, Japan.
Anal Sci. 2022 Mar;38(3):601-605. doi: 10.1007/s44211-022-00074-x. Epub 2022 Feb 18.
Real-time examination of water behavior in cuticle, cortex, and medulla of untreated and bleached hair was performed by Fourier-transform infrared (FT-IR) microscopy. Penetration of heavy water from the cuticle to the medulla was visualized and quantified by monitoring the O-D stretching band located at 2500 cm. The medulla of untreated hair had a significantly higher peak O-D intensity from 20 min after the heavy water penetration to 20 min after drying than that of bleached hair. Furthermore, heavy water evaporated 1 h slower in untreated hair than in bleached hair in any part. These differences may be due to the increase of S=O stretching of sulfonic acid caused to breaking of the disulfide and thioester bonds by bleach treatment. The method proposed in this study revealed potential application in visualizing and quantifying real-time water behavior in hair.
通过傅里叶变换红外（FT-IR）显微镜实时检查未经处理和漂白发的表皮、皮层和髓质中的水分行为。通过监测位于 2500cm 处的 O-D 伸缩带，可视化和量化了重水从表皮渗透到髓质的情况。未经处理的头发的髓质在重水渗透后 20 分钟至干燥后 20 分钟的 O-D 强度峰值明显高于漂白发的头发。此外，在任何部位，未经处理的头发中的重水蒸发速度比漂白发的头发慢 1 小时。这些差异可能是由于漂白发过程中破坏二硫键和硫酯键导致磺酸的 S=O 伸缩增加所致。本研究中提出的方法可能在可视化和定量头发中实时水分行为方面具有潜在应用。
