| A closed loop dynamic needle sampling method was developed for the determination of volatile components in cigarette tobacco by gas chromatography-mass spectrometry（GC-MS）.The collection mode,trapping and desorption conditions were optimized,and the desorption rate of dynamic needle trap（NT） was investigated,which was compared with that of solid phase microextraction（SPME）.The optimal conditions were as follows:a needle filled with Carboxen1000 material was used to trap the sample at a heating temperature of 80 ℃,with a velocity of 3 mL/min,a capturing time of 30 min,a desorption temperature of 250 ℃ and a desorption time of 5 min.Under the optimized conditions,45 compounds including tobacco organic acids,esters,aldehydes,alcohols etc.were detected,among which 27 species,accounting for 60% of total compounds,had the relative standard deviations less than 5%.The NT method,with better sensitivity and repeatability,is more suitable than solid phase microextraction method for the analysis of volatile components in cigarette tobacco. |