将烟丝样品置于温度（20±1）℃及相对湿度（60±3）%条件下平衡24 h。称取此样品4.0 g置于Dionex ASE 350萃取仪的34 mL萃取池中，用正己烷作为溶剂进行加速溶剂萃取（ASE）。加速萃取的温度为100℃，静态萃取时间为5 min，循环次数为2次。于萃取液中加入乙酸苯甲酯内标（100 mg·L^-1）溶液0.50 mL，混匀后经0.45 μm滤膜过滤，取滤液进行气相色谱-串联质谱法分析。采用HP-5MS毛细管色谱柱（30 m×0.25 mm，0.25 μm），在60~280℃温度区间程序升温模式分离后，按电子轰击离子源和多反应监测模式条件进行串联质谱测定。所测定的5种羧酸苯乙酯的质量浓度均在0.10~10.00 mg·L^-1内与其对应的峰面积之间呈线性关系，其检出限（3S/N）均为0.01 mg·L^-1。按标准加入法测定了方法的回收率，结果为91.0%~107%，测定值的相对标准偏差（n=6）均小于10%。同一批次内和不同批次间外加标记物的变异系数（CV_i）分别为5.8%~8.8%和6.3%~8.4%，说明加香工序的均匀性良好。

Cut tobacco sample was equilibrated for 24 h under the condition of (20±1)℃ and relative humidity of (60±3)%. A portion (4.0 g) of the equilibrated sample was taken and transferred to the 34 mL of extraction cell of the Dionex ASE 350 extractor and submitted to ASE with n-hexane. In ASE process, conditions of temperature (100℃), static extraction time (5 min), and cycling frequency (2 times) were adopted. The extract was separated and 0.50 mL of 100 mg·L^-1 phenylmethyl acetate solution was added as internal standard. After well mixing and filtration through 0.45 μm filtering membrane, the filtrate was used for GC-MS/MS analysis. Chromatographic separation was carried out on HP-5MS capillary column (30 m×0.25 mm, 0.25 μm) and under the mode of programmed temperature elevation ranged from 60℃ to 280℃. EI and MRM mode were used in MS/MS determination. Linearily ranges of standard curves of the 5 phenylethyl carboxylates determined were found same between 0.10 mg·L^-1 and 10.00 mg·L^-1, and their detection limits (3S/N) were found having the same value of 0.01 mg·L^-1. Recovery was tested by standard addition method, and the results of recovery were found in the range of 91.0%-107%, and values of RSDs (n=6) were found all less than 10%. Uniformity of aromatizing process for the cut tobacco were tested on samples taken from intra and inter production batches of the aromatizing process, giving values of coefficients of variation (CV_i) in the ranges of 5.8%-8.8% and 6.3%-8.4%, respectively, showing that the uniformity of aromatizing was good and satifactory.