Hydrophobic adsorption enrichment was used as the main pretreatment procedure for non-volatile or semi-volatile compounds, while headspace techniques were introduced for volatiles.

• 把顶端空间-气相色谱作为易挥发物的主要测试手段，把疏水富集-选择性分离-气相色谱（或液相色谱）作为难挥发有机物的检测途径。