Objective: To separate and identify volatile and fat-soluble components in Tibetan medicine Brag-zhun by GC-MS. Method: The water distillation method was used to extract the volatile components

and petroleum ether was used to extract fat-soluble components. GC-MS technology was used to separate and identify the components. The peak area normalization method was used to calculate the relative content of each component. Result: Forty-one chemical components were identified in volatile components of Brag-zhun

accounting for 45.67% of the total weight

there were 6 kinds of component relative content of over 2%: 1-naphthalenepropanol

a-ethenyldecahydro-a

5

5

8a-tetramethyl-2-methylene-

(aR

1S

4aS

8aS)- (11.97%)

cis-verbenol(6.38%)

α-copaene(2.67%)

2-tetradecene

(E)-(2.56%)

cedrol(2.49%)

docosanoic (2.17%); forty-five chemical components were identified in fat-soluble components in Brag-zhun

taking up 92.86% of the total weight

there were 14 kinds of component relative content of over 2%: eicosane(12.83%)

pentacosane(11.60%)

methyl palmitate(8.88%)

triacontane(6.82%)

heptadecane(5.94%)

5-eicosene

(E)- (5.92%)

1-hexacosanol(3.50%)

hentriacontane(3.43%)

1-naphthalenepropanol

a-ethenyldeca-hydro-a

5

5

8a-tetramethyl-2-methylene-

(aR

1S

4aS

8aS)- (3.18%)

methyl eicosanoate(3.15%)

methyl stearate(2.94%)

behenicacid methyl ester(2.89%)

heneicosane(2.55%)

tetracosanoic acid

methyl ester(2.15%). Conclusion: This study focused on volatile and fat-soluble components in Brag-zhun for the first time

in order to provide the study basis for further defining the formation mechanism of Brag-zhun.