摘要

The authors have synthesized a dummy molecularly imprinted monolith (MIM) in the tip of a micropipette using a sol-gel method. The MIM was applied to selective solid-phase microextraction (SPME) of vanillin (VN) and methyl vanillin (MV) prior to their determination by HPLC. The MIM was characterized by thermogravimetric analysis, scanning electron microscopy and FTIR. Some parameters affecting SPME were optimized. Then, a sensitive SPME/HPLC method was developed for the determination of VN and MV in infant milk powder. Under optimized conditions, the response is linear in the 2 to 3000 mu ga (TM) kg(-1) VN concentration range and in the 3 to 2000 mu ga (TM) kg(-1) range for MV. The detection limits (for an S/N ratio of 3) are 0.5 and 1 mu ga (TM) kg(-1), and the recoveries are between 83 and 110% for VN and between 80 and 101% for MV.