顶空固相微萃取-气相色谱法测定生活饮用水中痕量1，4-二氧六环

摘要

A method for the detection of trace 1,4⁃dioxane in drinking water using headspace solid⁃phase microextraction ( HS/SPME ) with gas chromatography/flame ionization detector ( FID) was presented. Both the extraction conditions ( SPME fiber, extraction temperature, extraction time, pH and sample volume, et al) and the gas chromatographic conditions were optimized. The results showed that the best response was obtained with 85μm Carboxen⁃PDMS above 3 mL water in a 20⁃mL screw capped vial containing 3 mL sodium hydroxide solution ( 600 g/L) . The best chromatographic separation was obtained on a PTA⁃5 capillary column ( 30 m × 0�53 mm × 3�0 μm ) which was modified with alkali⁃bonding and of large pores and thick film. The linear range for 1,4⁃dioxane was 0�50-50�0μg/L with the correlation coefficient ( r) of 0�999 5. The limit of detection ( S/N>3) was 0�14μg/L. The recoveries for the actual water samples at low, medium and high spiked levels were 95�5%-107%, with the relative standard deviations of 1�1%-5�3% ( n=6) . The developed method is simple, accurate, reproducible and highly sensitive. It is suitable for the routine monitoring of trace amount of 1,4⁃dioxane in the drinking water.%建立了生活饮用水中痕量1，4⁃二氧六环的顶空固相微萃取（ HS／SPME）⁃气相色谱测定方法。考察并优化了萃取头、萃取温度、萃取时间、pH值、样品量、色谱条件等参数。结果表明：提取效率较好的方法是3 mL水样中加入3 mL 600 g／L氢氧化钠溶液，用85μm Carboxen⁃PDMS萃取头萃取，用键合碱改性的大口径、厚液膜PTA⁃5毛细管色谱柱测定。1，4⁃二氧六环在0�50～50�0μg／L范围内线性关系良好，相关系数为0�9995；方法检出限（以S／N＞3计）为0�14μg／L；相对标准偏差为2�1％～4�5％（ n＝6）；对实际样品中进行线性范围内的高、中、低3个加标水平的测定，回收率为95�5％～107％，相对标准偏差为1�1％～5�3％（ n＝6）。建立的方法简便、准确、重现性好、灵敏度高，适合生活饮用水中痕量1，4⁃二氧六环的常规监测。