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目的对溶胶-凝胶法制备的乐果分子印迹固相微萃取头进行评价,并建立分子印迹固相微萃取与气相色谱联用(molecularly imprinted polymer-solid phase microextraction/gas chromatography,MIP-SPME/GC)检测环境水中乐果残留量的方法。方法以非印迹(nonimprinted polymer,NIP)SPME萃取头为参照,考查乐果分子印迹(MIP)萃取头的使用性能;优化SPME萃取条件后,对MIP-SPME/GC方法的分析性能进行评价,最后检测实际样品。结果该MIP萃取头的热稳定性和化学稳定性高,在水相中萃取选择性好。在优化条件下,方法在蒸馏水中线性范围为12.5~2500μg/L,线性相关系数为0.9997,检出限为97.0 ng/L,5次重复实验所得RSD为6.45%。应用本方法测定湖水和自来水中乐果含量,均未有乐果检出。自来水中方法的加标回收率在92.0%~114.2%之间,湖水中加标回收率为88.9%~102.1%。结论溶胶-凝胶分子印迹SPME萃取头具有很高的操作稳定性,能够用于水相识别。本方法简便、精密度高、准确度好,在富水样品的乐果检测中具有明显优势。
OBJECTIVE To evaluate the molecularly imprinted solid phase microextraction heads made by sol-gel method and to establish molecularly imprinted polymer-solid phase microextraction / gas chromatography (MIP-SPME / GC) method for detecting the amount of dimethoate residues in environmental water. Methods The non-imprinted (NIP) SPME extraction heads were used as reference to test the performance of MIP extraction heads. After optimization of SPME extraction conditions, the analytical performance of MIP-SPME / GC method was evaluated. Finally, Test the actual sample. Results The MIP extraction head has high thermal and chemical stability and good extraction selectivity in the aqueous phase. Under optimized conditions, the linear range was 12.5-2500 μg / L in distilled water, the linear correlation coefficient was 0.9997, the detection limit was 97.0 ng / L, and the RSD of 5 replicates was 6.45%. Application of this method for the determination of dimethoate in tap water and water, were not detected. The spiked recoveries of tap water from 92.0% to 114.2% and the spiked recoveries of 88.9% to 102.1% in lake water. Conclusion The sol-gel molecularly imprinted SPME extraction tip has high operational stability and can be used for water phase identification. The method is simple, high precision and good accuracy, and has obvious advantages in the detection of dimethoate in water-rich samples.