Sayuri Kato (1), Eri Goya (2), Makoto Kanauchi (3), Takumi Miyazawa (3), Masahito Muro (1), Kimiko Nakajima (4), Yoshihiro Saito (5), Yukako Sato (4), Miho Sawada (6), Izumi Sekine (1), Atsushi Suzuki (2), Masayuki Takahashi (7), Hiroshi Takakuwa (8), Junichi Toyota (9), Fumihiko Tsuchiya (10), Takayuki Watanabe (11); (1) Kirin Company, Ltd., Yokohama, Japan; (2) Orion Breweries, Ltd., Japan; (3) Miyagi University, Japan; (4) Asahi Breweries, Ltd., Japan; (5) Shimadzu Co., Japan; (6) Suntory Beer, Ltd., Japan; (7) National Research Institute of Brewing, Japan; (8) Agilent Technologies Japan, Ltd., Japan; (9) Kinryo Electric Co., Ltd., Japan; (10) Thermo Fisher Scientific K. K., Japan; (11) Sapporo Breweries, Ltd., Japan
Currently, lower boiling volatiles in beer are determined by headspace GC-FID, a method described in the Methods of Analysis of the BCOJ. Whereas GC-FID has a wide dynamic range and the instrument is inexpensive, the method cannot distinguish substances that have the same retention time. This problem is more frequently encountered these days, as beer varieties have increasingly diversified in Japan. Moreover the GC-FID method for determination of lower boiling volatiles is often affected by impurities. Under these backgrounds, we evaluated the headspace GC/MS method as a potential alternative for analysis of lower boiling volatiles in beer. In addition, our preliminary study showed a better separation of i-amyl alcohol and active amyl alcohol by changing the GC column from that adopted in the Methods of Analysis of the BCOJ. Therefore we used the new GC column for further investigation, and the collaborative work was conducted by 13 laboratories. The statistical summary of results was shown as follows: RSDr ranged from 1.5 to 3.2% for n-propyl alcohol, 2.9 to 7.9% for ethyl acetate, 1.8 to 6.1% for iso-butyl alcohol, 1.4 to 5.2% for iso-amyl alcohol, 1.8 to 5.9% for active amyl alcohol, and 3.3 to 14.4% for iso-amyl acetate; RSDR ranged from 8.8 to 14.3% for n-propyl alcohol, 10.9 to 15.3% for ethyl acetate, 4.7 to 9.7% for iso-butyl alcohol, 7.9 to 9.7% for iso-amyl alcohol, 4.3 to 8.1% for active amyl alcohol, and 15.9 to 22.8% for iso-amyl acetate. We judged these results were acceptable. Taken collectively, GC/MS was shown to have high sensitivity, selectivity and identification capability and is considered as an excellent alternative approach to GC-FID. The subcommittee recommended that the determination of lower boiling volatiles in beer by headspace GC/MS method be adopted for inclusion in the Methods of Analysis of the BCOJ.
Sayuri Kato received a degree from the Department of Food and Nutrition, Japan Women’s University, Japan. She began work as a chemical analyst in 2011 at Kirin Company Ltd. She has been a member of the BCOJ Analysis Committee since 2015.