顶空固相微萃取-气相色谱-质谱联用法分析竹醋液挥发性化合物

为探讨精制前后竹醋液挥发性有机化合物(VOCs)及不同极性萃取纤维头对VOCs的萃取效果, 采用2种不同极性萃取纤维头的顶空固相微萃取法(HS-SPME)萃取精制前后竹醋液VOCs, 并通过气相色谱-质谱(GC-MS)分析。2种纤维头萃取出精制前后竹醋液54和57种有机化合物, 其中竹醋原液中聚二甲基硅氧烷(PDMS)纤维头萃取出41种, 主要为2-甲氧基-苯酚(9.03%), 4-乙基-苯酚(8.36%), 苯酚(6.48%), 聚丙烯酸酯(PA)纤维头萃取出32种, 主要为苯酚(17.23%), 2-甲氧基-苯酚(12.73%), 乙酸(11.80%);精制液中PDMS纤维头萃取出42种, 主要为2-甲氧基-苯酚(12.09%), 4-乙基-苯酚(8.86%), 苯酚(6.80%)等, PA纤维头萃取出35种, 主要为苯酚(19.66%), 2-甲氧基-苯酚(14.72%), 乙酸(6.65%)等。结果显示:PA纤维头对精制前后竹醋液中酸类、酚类和醛类的吸附力优于PDMS纤维头, 其中在对酸类的吸附上PA纤维头有较为显著的优势;而在酮类和烯类上PDMS纤维头的吸附力要优于PA纤维头。因此, 在使用固相微萃取萃取竹醋液中不同的成分时应该有选择地使用纤维头以便较准确地萃取出目标成分。

Volatile compounds from bamboo vinegar with HS-SPME and GC-MS

Our former work has discovered that bamboo vinegar may be a new olfactory disturbance agent against mosquitoes. It is necessary that the further work on volatile organic compounds from original and refined bamboo vinegar in order to display effect of mosquito repellent. Original and refined bamboo vinegar VOCs were extracted using two kinds of extraction fiber heads with different polarity and then analyzed by gas chromatography-mass spectrometry (GC-MS) and headspace solid-phase microextraction (HS-SPME). The result showed that extraction of 54 compounds from original bamboo vinegar and 57 compounds from refined bamboo vinegar, respectively. From the original bamboo vinegar, the polydimethylsiloxane (PDMS) fiber extracted 41 compounds:mainly 2-methoxy-phenol (9.0%), 4-ethyl-phenol (8.4%), and phenol (6.5%); and the polyacrylate (PA) fiber extracted 32 compounds:primarily phenol (17.2%), 2-methoxy-phenol (12.7%), and acetic acid (11.8%). From the refined bamboo vinegar, the PDMS fiber extracted 42 compounds:mainly-methoxy-phenol (12.1%), 4-ethyl-phenol (8.9%), and phenol (6.8%) with the PA fiber extracting 35 compounds:mostly phenol (19.7%), 2-methoxy-phenol (14.7%), and acetic acid (6.7%). These results showed that for acids, phenol, and aldehyde from the original and refined bamboo vinegar, extraction with the PA fiber had a stronger adsorptive attraction than the PDMS fiber head. The PA fiber was superior in the adsorption of acids; whereas, the adsorptive attraction of the PDMS textile fiber head on the ketones and alkenes surpassed the PA textile fiber head's. The corresponding fiber may be used to extract the target component owing to improving precision effect on extracting various ingredients of bamboo vinegar.