固相微萃取结合气相色谱-质谱检测饮用水中 5种异味化合物

Detection of 5 off-flavors in drinking water by solid phase micro-extraction coupled with gas chromatography-mass spectrometry

中文关键词:  饮用水  固相微萃取  气相色谱-质谱法  致嗅物

英文关键词:drinking water  solid phase micro-extraction  gas chromatography-mass spectrometry  off-flavor

中文摘要:

      目的 建立固相微萃取(SPME)结合气相色谱-质谱法检测饮用水中5种挥发性痕量异味化合物的分析方法。方法 采用CAR/DVB/PDMS纤维涂层萃取头插入装有5种标准化合物的40 mL顶空瓶中, 加入6 g NaCl, 80 ℃下平衡20 min, 吸附40 min, 经过气相色谱-质谱检测, 对饮用水中常见的5种致异味化合物(2-甲基异莰醇(MIB)、2,4,6-三氯茴香醚(2,4,6-TCA), 土臭素(GSM), 2-甲氧基-3-异丙基吡嗪(IPMP), 2-甲氧基-3-异丁基吡嗪(IBMP))进行检测。分别优化固相微萃取的萃取头、加盐量、萃取温度以及萃取时间等因素。结果 最优提取条件: 65 μm PDMS/CAR/DVB纤维头, 30%(m/v)加盐量, 萃取温度60 ℃, 萃取时间40 min。5种异味化合物在1~100 ng/L范围内线性关系良好, R2>0.971, 检出限分别为1.0、1.0、0.8、1.0、1.0 ng/L, 精密度小于10%。结论 本方法检测限低, 灵敏度高, 是检测饮用水样异味的良好方法。

英文摘要:

      Objective To establish a method to detect 5 kinds of trace amounts of volatile odor compounds in drinking water by solid phase micro-extraction (SPME) combined with gas chromatography- mass spectrometry. Methods CAR/DVB/PDMS fiber coating was inserted in 40 mL vial with 5 kinds of standard compounds, adding 6 g NaCl, under 80 ℃ balancing 20 min, adsorbing 40 min, and 5 kinds of compounds that often causing off-flavor in drinking water, including 2-methylisoborneol (2-MIB), 2,4,6-trichloroanisole (2,4,6-TCA), trans-1,10-dimethyl-trans-9-decalol (Geosmin), 2-isopropyl-3-methoxypyrazine (IPMP) and 2-isobutyl-3-methoxypyrazine (IBMP), were detected by gas chromatography-mass spectrometry. Extraction head, salt amount, extraction temperature and extraction time and other factors were optimized. Results The optimum extraction conditions were listed as follows: 65 μm PDMS/CAR/DVB fiber head, 30% (m/v) the amount of salt, extraction temperature 60 ℃, and extraction time 40 min. The 5 kinds of odor compounds showed an excellent linear relationship between 1~100 ng/L, with the correlation coefficient more than 0.971, and the detection limits were 1.0, 1.0, 0.8, 1.0, and 1 ng/L, respectively, and the precision was less than 10%. Conclusion This method is an effective method to detect the odor of drinking water samples, with low detection limit and high sensitivity.