Abstract:

The volatile compounds of water extracts from walnut diaphragm were extracted by using four different polar
solid-phase micro-extraction (SPME) fibers, separated by either of two chromatographic columns, HP-5 (with weak polarity)
and RTX-WAX (with strong polarity), and analyzed by using head-space solid-phase micro-extraction (HS-SPME) and gas
chromatography-mass spectrometry (GC-MS). Further, the effects of different chromatographic columns and extraction
fibers on the analysis of volatile components were examined. Results showed that a total of 115 volatile compounds with
known structure from four walnut diaphragm extracts were separated on different chromatographic columns and identified
by GC-MS, consisting of 21 alcohols, 18 esters, 15 ketones, 14 aromatic compounds, 13 hydrocarbons, 12 aldehydes,
6 acids, 5 phenolic compounds, 2 ethers and 9 other compounds. The main volatile components were acetic acid, ethyl
acetate, 2,6-dibutyl-4-methylphenol, menthol, cedrol, 2,3-butanediol, 1-hexanol, phenethylalcohol, 3-butyl-4-hydroxyanisole,
hexanal, and azulene.

Key words: gas chromatography-mass spectrometry (GC-MS), walnut diaphragm, water extracts, volatile composition