gas-chromatography/mass spectrometry information

gas-chromatography/mass spectrometry information (gyasˑ-krō·m·tˑ·gr·fē/masˑ spek·trˑ·m·trē in·fr·māˑ·shn),

n details about the relative concentration of components in an essential oil, used as an aid in determining the oil's purity.