Analysis of Thujopsene in Antimicrobial/Deodorant Processed Textiles as an Index of Hiba Oil

The use of hiba oil (cypress oil) as a safe and natural antimicrobial agent for textiles is on the rise. For investigating the hiba oil content of commercially available textiles, the authors developed an analytical method using thujopsene, the main ingredient of hiba oil, as an index. First, standard fabrics were prepared by fixing microcapsules filled with hiba oil. Using these fabrics, detection of thujopsene by gas chromatography mass spectrometry (GC⁄MS), extraction of thujopsene from textiles, and purification of the extract were studied, and then an analytical method for finding thujopsene on the level of ng⁄g-fabric was established. Next, in order to estimate the survivability of thujopsene in marketed products, the JIS color fastness test was performed for the hiba-oil-treated fabrics, and the survival rate of thujopsene in those fabrics was observed. It was proven that thujopsene continued to remain on the level of ng⁄g-fabric. Furthermore, analysis of thujopsene was carried out for 23 kinds of textile products labeled “processed with hiba oil or hinokitiol,” which were purchased in the past five years. As a result, thujopsene was detected in 21 products, proving that most commercially available products had been processed with hiba oil. This analytical method is considered effective in determining whether a textile product was actually processed with hiba oil.