Methods: Crushed samples were extracted from solvent, isolated and purified with SPE, concentrated and analysised by GC/ECD, quantitatived by external standard method.

• 方法：样品粉碎后经溶剂提取、固相萃取分离净化和氮吹仪浓缩后，进入GC/ECD分析，外标法定量。