Investigation of pyrolysis behaviour of lutein in air by thermo gravimetry-single drop micro extraction-gas chromatography-mass spectrometry
To investigate the pyrolysis behaviour of lutein in air, an automatic single drop micro extraction (SDME) device for trapping the released fractions was designed and coupled with thermo gravimetry-gas chromatography-mass spectrometry. According to the results of thermogravimetric - differential thermal analysis (TG-DTA), the pyrolysis process was divided into 16 temperature sections in the range of 155-400 °C. The released fractions from thermo gravimetric analyser were automatically extracted with ethanol by SDME. The extract effect of SDME was analysed by comparing the mass loss in each temperature section with the total peak area of pyrolysis products. The results indicated that: 1) The optimised conditions for the thermo analyser were: temperature ascending rate 5 °C/min and carrier gas flow rate 400 mL/min. 2) SDME was excellent in the extraction of volatile components in pyrolysis products. 3) The probable mechanism for the formation of major aromatic substances in lutein pyrolysis was inferred on the basis of monitoring the dynamic changes of relative contents among 43 main pyrolytic components. 4) The main components identified by GC/MS were ketones, aldehydes, alcohols, alkenes and aromatic hydrocarbons, the major pyrolysis products were ß-damascenone megastigmatrienone and 4-oxoisophorone. The pyrolysis behaviour of lutein in air provided a reference for analysing the pyrolysis behaviour of tobacco components during smoking.