Six genotypes of wheat straw were burned under different conditions, and both n-alkanols and n-Alkenes in the smoke (PM2.5) were measured. In flaming PM2.5, n-alkanols with carbon number of C8to C32 were identified, the total contents of which ranged from 381.1 to 30178.6mg/kg, with a mean value of 10011.3mg/kg. The varying ranges for C24/C28, C26/C28 and C28/∑were 4.1%to 69.6%, 0.9%to 9.8%and 45.3%to 92.8%, respectively. The distribution pattern for the compounds was unimodal with a peak at C28. The carbon predominance index (CPI) ranged from 25.8 to 133.0, whose mean value was 56.1. In the smoldering PM2.5, the same individual n-alkanols were found, and the total amount changed from 944.4 to 135858.2mg/kg, with an average value of 28160.2mg/kg. The ratio values of C24/C28, C26/C28 and C28/∑were in the range of 2.4%to 22.2%, 0.6%to 8.6%, and 70.8%to 95.7%, respectively. The distribution pattern was similar to that in flaming PM2.5, and the CPI varied from 23.1 to 266.6, the mean of which was 82.4. In flaming PM2.5, n-alkenes were composed of C17 to C29. The total contents of the compounds were in the range of 67.1 to 733.0mg/kg, whose average value was 261.8mg/kg. The ratios of the content for n-alkenes with lower carbon number to that for ones with higher carbon number (L/H) ranged from 0.8to 2.2, the mean of which was 1.5. The distribution of n-alkenes was unimodal with maximal carbon number (Cmax) of C24mainly. The CPI values varied from 0.9 to 1.6, and its mean value was 1.2. In the smoldering PM2.5, n-alkenes from C16 to C29 were identified, the total amounts of which were in the range of 273.9~862.4mg/kg, and the mean value was 574.1mg/kg. The L/H ratios changed from 0.5 to 2.2, and the average was 1.6. The distribution pattern was similar to that in flaming PM2.5, but the Cmax was C22. The CPI values varied from 1.0 to 2.1, and the mean was 1.2. C24/C28, C26/C28 and C28/∑are maybe useful proxies for recognizing n-alkanols from wheat straw combustion in ambient aerosols. Cmax has significance in distinguishing n-alkenes originated from wheat straw burning under flaming and smoldering conditions.%对6种麦草开展了燃烧试验,测定了烟尘(PM 2.5)中正构脂肪醇和正构烯烃的化学组成.结果显示,在明火PM 2.5中正构脂肪醇由C8~C32组成.其总含量为381.1~30178.6mg/kg,平均为10011.3mg/kg.C24/C28、C26/C28、C28/∑等百分比的变化范围分别为4.1%~69.6%、0.9%~9.8%、45.3%~92.8%.正构脂肪醇呈单峰型分布,C28是主峰碳(Cmax).其 CPI 值在25.8~133.0间变化,平均为56.1.在闷烧 PM 2.5中正构脂肪醇由C8~C32组成.其总含量为944.4~135858.2mg/kg,平均为28160.2mg/kg.C24/C28、C26/C28、C28/∑等百分比的变化范围分别为2.4%~22.2%、0.6%~8.6%、70.8%~95.7%.正构脂肪醇的分布模式与明火PM 2.5的相同.其CPI值分布于23.1~266.6间,平均为82.4.明火PM 2.5中的正构烯烃由C17~C29组成.其总含量在67.1~733.0mg/kg之间变动,平均为261.8mg/kg.低碳数与高碳数正构烯烃的含量之比(L/H)为0.8~2.2,平均值为1.5.正构烯烃呈单峰式分布,Cmax以C24为主,C22次之.其CPI值分布于0.9~1.6之间,平均为1.2.闷烧PM 2.5中的正构烯烃由C16~C29组成.其总含量分布于273.9~862.4mg/kg之间,平均为574.1mg/kg.其L/H比值在0.5~2.2之间波动,平均值为1.6.正构烯烃的分布模式与明火PM 2.5类似,但Cmax以C22为主,C24次之.其CPI值的变化区间是1.0~2.1,平均值为1.2.C24/C28、C26/C28、C28/∑等指标对于识别气溶胶中麦草燃烧来源的正构脂肪醇具有参考意义.利用Cmax可区分麦秸在明火和闷烧条件下生成的正构烯烃.
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