Method: the components were separated and iden tified by GC-MS and match with NIST/EPA/NIH library, the relative contents in p ercentage were calculated by peek area normalization method.

• 方法：用气质联用技术和标准图谱检索对照、核对和补充检查的方法分离和鉴定各化学组分，用离子流色谱峰面积归一法计算各化学成分的相对含量。