Objective: To identify chemical components in volatile oil from Machilus salicina Hance and determine their relative contents. Method: Volatile oil from fresh leaves of M. salicina Hance was extracted by hydrodistillation.GC-MS was adopted to analyze chemical constituents in volatile oil and determined their relative contents

mass spectrometric conditions were as follows:HP-FFAP quartz capillary column(0.25 mm×30 m

0.25 μm)

the starting temperature 40℃

heated to 200℃ with 5℃· min-1

maintained 5 min

then with 8℃· min-1 heated to 280℃ until completion of analysis

helium as the carrier gas(99.999% )

column flow rate 1.0 mL· min-1

inlet temperature 250℃

split ratio 50:1

EI ionization source 70 eV

ion source temperature 230℃

quadrupole temperature 180℃

solvent delayed 2.5 min

scan range of m/z 50-550. Result: Yield of volatile oil was 1.05%

68 kinds of compounds were obtained and 55 kinds of compounds(accounted for 77.10% of total mass of volatile oil) were identified

26 of them was olefinic compounds

12 of them was alcohol compounds

the concentration of (Z)-nerolidol

spoon eudesmol and ledol were 12.62%

7.48% and 5.38%

respectively. Conclusion: GC-MS could be used to identify and determine content of volatile components

this study could provide experimental basis for development and utilization of M. salicina Hance.