将样品研磨混匀，称取0.050 0 g，用10 mL甲醇超声萃取10 min，静置后取上清液，用0.22 μm微孔滤膜过滤，滤液用甲醇稀释后采用离子迁移谱法测定其中的西布曲明、酚酞、芬氟拉明、咖啡因和麻黄碱。优化的测定条件如下：离子源电压2 550 V，迁移管电压7 350 V，迁移管温度180℃，迁移气流量1.5 L·min^-1，排除气流量0.8 L·min^-1。5种非法添加物的质量浓度均在0.10~20 mg·L^-1内与对应的峰面积呈线性关系，检出限（3S/N）在0.05~0.10 mg·L^-1之间。加标回收率在71.9%~91.3%之间，测定值的相对标准偏差（n=6）小于10%。方法用于测定6种市售减肥类保健品中上述5种非法添加物，1种样品中检出酚酞，其质量比为3.1 mg·g^-1；另外两种样品中检出咖啡因，其质量比分别为1.6，41.6 mg·g^-1。

After the sample was ground and mixed well, 0.050 0 g of the sample was ultrasonically extracted with 10 mL of methanol for 10 min. After standing, the supernatant was taken and filtered through a 0.22 μm microporous membrane. The filtrate was diluted with methanol. Sibutramine, phenolphthalein, fenfluramine, caffeine and ephedrine in the solution were determined by ion mobility spectrometry. The optimized conditions for determination were as follows:ion source voltage of 2 550 V, drift tube voltage of 7 350 V, drift tube temperature of 180℃, drift gas flow rate of 1.5 L·min^-1, and exhaust flow rate of 0.8 L·min^-1. Linear relationships between values of peak area and mass concentration of the five kinds of illegal additives were found in the same range of 0.10-20 mg·L^-1, and detection limit (3S/N) were in the range of 0.05-0.10 mg·L^-1. Values of recovery obtained by standard addition method were between 71.9% and 91.3%, and RSDs (n=6) were less than 10%. The method was used to determine the above five illegal additives in 6 kinds of commercially available weight loss health care products. Phenolphthalein was detected in one sample, with the mass ratio of 3.1 mg·g^-1; caffeine was detected in other two samples, with the mass ratio of 1.6, 41.6 mg·g^-1, respectively.