Variation of Tobacco-specific N-nitrosamines in Burley Tobacco Leaves During Aging

For investigating the variation rule of the contents of main tobacco-specific N-nitrosamines(TSNAs) in burley tobacco leaves during aging,the contents of NAB,NAT,NNK and NNN were regularly determined by taking the upper and middle leaves of major burley tobacco cultivars,TN86 and TN90,as experimental material.The results showed that:1) Comparing with their initial contents in leaves,NAB,NAT and NNN increased evidently after aging for 6,9,12,18,24 and 27 months;NNK increased obviously after aging for 6,18,24 and 27 months,while decreased slightly after aging for 9 months,the variation of NNK content after aging for 12 months significantly differed in dependence on tobacco varieties and stalk positions.2) The contents of NAB and NAT increased gradually with the prolongation of aging time during 0-18 months,which reached their maximum in the 18th month,after that decreased gradually.3) The variation of NNN content varied with tobacco varieties and stalk positions during aging for 0-27 months.