Saeki, K; Yamasaki, Dai; Mizoguchi, S; Kajiwara, H; Ohira, SI; Toda, Kei
Pollen allergy is serious health problem especially in Japan. Therefore, the forecasting and monitoring of pollen scattering have been a important techniques for decades. Conventionally, the pollen scattering is monitored by physical counting such as labor-required microscope observations or counting laser scattering. In this work, we started on investigation of chemical compounds contained in pollens because the identification of pollens and determination of pollen concentrations can be carried out chemically by monitoring atmospheric pollen compounds. First, organic compounds thermally desorbed from pollens were analyzed by GC/MS for commercially obtained conifer tree pollens, such as Japanese cedar (Cryptomeria japonica: C. japonica), Japanese cypress (Chamaecyparis obtusa: C. obtusa), and Japanese red pine (Pinus densiflora: P. densiflora), and broadleaf tree pollen namely Japanese chestnut (Castanea crenata: C. crenata) sampled in a trivial woods forest. Monoterpenes, nonanal, nonanoic acid, and sesquiterpene β-eudesmol were observed from all conifer tree pollens. In addition to these common compounds, kaur-15-ene, sclareol and 4-isopropyl-7,11- dimethyl-3,7,11-cyclotetradecatrienone (IDC) were observed only from Japanese cedar pollen. Also, hibaene from Japanese cypress, borneol and (13R)-8,13-epoxy-labd-14-ene from Japanese red pine were found as their specifical compounds. Benzyl alcohol, phenylethyl alcohol (PEA) and tetracosane were observed as characteristic compounds of Japanese chestnut. The same compounds were observed from the corresponding conifer tree pollens sampled in a neighboring forest, and it was shown that these compounds can be candidates for pollen markers. Next, pollens suspended in the atmosphere were collected by filter sampling. The particles were analyzed, as they were on a filter, by thermal desorptionâGC/MS, and IDC and PEA were detected from the filters. The concentrations of IDC and PEA varied according to changes in the cedar and chestnut pollen scatterings, respectively. It is expected that chemical observation will be available in the future for the identification and quantitative determinations of pollen scatterings by further detailed examinations and automated instrumentation. © 2018 The Japan Society for Analytical Chemistry.