Solid phase microextraction of volatile organic compounds released from leaves, roots and gum of Astragalus microcephalus Willd., followed by GC and GC/MS analysis.

A solid phase microextraction sampling method using homemade pencil-lead fibre coupled with gas chromatography was developed as a fast, easy and reliable monitoring technique to recognise the organic volatile compounds of the roots, leaves and gum of Astragalus microcephalus. The efficiency and reliability of different fibres such as homemade pencil-lead and commercial polydimethylsiloxan, as well as polyacrylate, were evaluated and the most effective fibre for recognition of these compounds was selected. Some effective experimental parameters, such as extraction time and chromatographic conditions, were examined and optimised. Under the optimised conditions, various volatile compounds such as 2-hexyn-1-ol, pentanal 3-methyl, caryophyllene, octadecane and some chlorinated components were identified in different parts of A. microcephalus. The results obtained showed that in distinct parts of A. microcephalus, the nature and level of the volatiles were varied.