固相微萃取－气相色谱质谱联用测定水中桉树叶溶出物

摘要

为评价桉树叶水溶物对水环境的影响，该研究采用固相微萃取（SPME）与气相色谱－质谱联用检测技术（GC －MS）研究了桉树叶在不同浸泡时间下的溶出物的组成与含量。在桉树叶溶出物中共发现139种化合物，但不同浸泡时间所获得的溶出物化学组分差异较大。与文献报道过的结果比较发现，采用 SPME 前处理方法可以鉴定出更多的化合物；同时，该研究也对桉树叶溶出物组分中相对丰度高（＞1％）、检出率大（＞80％）的22种化合物进行了相对定量分析。结果发现有7种组分和总有机碳（TOC）随浸泡时间增加而增加，其中TOC 在浸泡30 d 时到最大值（5848 ng／mL）并保持稳定。对溶出物样品中常规水质参数的分析结果发现，COD和 TN 超过国家《地表水环境质量标准》规定的Ⅴ类水质标准，而在浸泡15 d 后，其溶出物中的氨氮（NH ＋4－N）超过Ⅲ类水标准。因此，在水库等水源地附近种植的桉树，其桉树叶溶出物对水体环境质量存在一定的影响。%In order to reveal the effects of dissolved matters of eucalyptus leaves to the aquatic environ-ments.Solid phase microextraction (SPME)coupled with gas chromatography-mass spectrometry (GC-MS)was selected for qualitative and quantitative determination of dissolved matters of eucalyptus leaves in pure water during different immersing times in this study.By searching NIST database,139 different chemicals are identified with the matching degree higher than 85%,and the composition of dissolved matters varies significantly during the immersing time.While using SPME as the sample pretreatment method,the identified chemicals are much more than those reported previously.Moreover,22 chemicals with relative abundance higher than 1% and the detection rate higher than 80%,are investigated quanti-tatively.The result shows that 7 components increase by the increasing immersing times,and reach the highest concentration of 5 848 ng/mL after 30 days.Nevertheless,the COD and TN values of the dis-solved matters are inferior to Ⅴ class of surface water quality standards of China,while NH +4 -N is infe-rior to Ⅲ class after 15 days.Obviously,more attentions should be paid for the effects of dissolved mat-ters of eucalyptus Leaves to the aquatic environments.