将5.000 g样品加入乙腈-甲酸（199+1）混合液15 mL，匀浆30 s，振荡提取10 min后离心，下层固体再用乙腈-甲酸（199+1）混合液8 mL重复提取1次，合并上清液于平行蒸发管中，于55℃平行蒸发至干。用甲醇3 mL溶解残渣，再加入水7 mL，置于冰箱冷冻30 min后冷冻离心，取甲醇溶液层采用poly-sery HLB固相萃取柱净化，用20%（体积分数，下同）甲醇溶液6 mL淋洗，用90%甲醇溶液4 mL洗脱，洗脱液在50℃下用氮气吹干，用乙腈（1+1）溶液1 mL溶解残渣，过0.22 μm微孔滤膜。滤液在BEH C₁₈色谱柱（50 mm×2.1 mm，1.7 μm）上分离，流动相为乙腈（1+1）溶液，采用紫外检测器，检测波长为254 nm。甲基睾酮质量浓度在0.05~1.00 mg·L^-1内与对应的峰面积呈线性关系，检出限（3S/N）为5.0 μg·kg^-1。在10.0，50.0，100 μg·kg^-1浓度水平上进行加标回收试验，回收率为73.6%~91.4%，测定值的相对标准偏差（n=5）小于9.0%。

The sample (5.000 g) was added into 15 mL of acetonitrile-formic acid (199+1) solution, and the mixture was homogenized for 30 s, then extracted by shaking for 10 min and centrifuged. The lower solid was then extracted with 8 mL of acetonitrile-formic acid (199+1) aolution. The supernatant was merged in a parallel evaporation tube and evaporated to dryness at 55℃. The residue was dissolved with 3 mL of methanol, and 7 mL of water was added. The solution was freezed in the freezer for 30 min and then centrifuged. The methanol solution layer was purified with poly-sery HLB solid phase extraction column, using 6 mL of 20% (φ) methanol solution for rinse and 4 mL of 90% (φ) methanol solution for elution. After the eluate was dried at 50℃ by nitrogen blowing, the residue was dissolved in 1 mL of acetonitrile (1+1) solution and the solution was filtered with a 0.22 μm microporous membrane filter. The filtrate was separated on a BEH C₁₈ column (50 mm×2.1 mm, 1.7 μm) with acetonitrile (1+1) solution as the mobile phase. Methyltestosterone was detected by a UV detector at the wavelength of 254 nm. Linear relationship was found between peak area and mass concentration of methyltestosterone in the range of 0.05-1.00 mg·L^-1, with detection limit (3S/N) of 5.0 μg·kg^-1. Test for recovery by standard addition method was carred out at the spike level of 10.0, 50.0, 100 μg·kg^-1, giving results in the range of 73.6%-91.4%, and RSDs (n=5) were less than 9.0%.