To develop a novel spectroscopic method for quantitative evaluation of detergency, attenuated total reflection (ATR)-FT/IR spectroscopy was applied for quantitative analysis of oil- and protein-based soil components adhering to cotton fibres without precedent extraction procedure. In addition, influence of washing time and mechanical action on the detergency of soap (sodium salt of fatty acid) for soils on clothing was examined by using this method. In particular, oil- and protein-based soil contents can be separately estimated using relative intensities of their characteristic IR bands of CH₂ and CH₃ stretching (2930 and 2850 cm^-1) and Amide I (1650 cm^-1), respectively. In case of washing at a rotation rate of 60 rpm, no change was observed for the detergency of oil-based component between 1 and 15 min, whereas the detergency of proteinbased component slightly increased over 10 min. By contrast, in case of washing at 120 rpm, the detergency of two soil components remarkably increased with an increase of washing time. By using ATR-FT/IR method,oil- and protein-based soil components attached to the same surface of a wet-type artificially soiled fabric can be directly and separately quantified at the same time.

Chicken eggshell membrane (ESM) is composed of a non-woven fibrous biopolymer fabric crosslinked by collagen (mainly types X and V), lysyl oxidase, and other molecules, including glycoproteins and lipids, which are secreted by cells in the hen’s fallopian tube. ESM has been reported to improve osteoarthritic knee pain when taken as a supplement and to have anti-fibrotic effects in rodents. ESM has physiological effects in vivo after digestion, absorption, and metabolism, but the mechanism of ESM efficacy remains unclear. We aimed to determine whether ESM is digested and absorbed by the body, although its metabolic mechanism has not been described. Although it is possible to create compounds labeled with single molecules,ESMs are insoluble, fibrillar, natural composite materials, and the molecular form of digested and absorbed ESM is unknown, so it is not possible to prepare synthetically labeled compounds. We developed a method for direct tritium labeling of ESM and investigated the absorption of the labeled ESM. Organic compounds, such as proteins, were mixed with lithium carbonate and then irradiated to label with ³H produced by the ⁶Li (n, α) ³ H reaction. Mice were orally administered tritium-labeled ESM, and blood and tissue radioactivity were measured using a liquid scintillation counter. Tritium-labeled ESM was distributed in the blood and all tissues after oral administration. Our method enabled successful tritium labeling of fibrous ESM, which allowed for metabolic evaluation of the labeled ESM product as it was digested and absorbed by the organs of experimental mice. This advanced tritium recoiling labeling method can be used for in vivo tracking of complex acellular extracellular matrix bioscaffolds used in biomedical research.