分子印迹固相萃取-化学发光法测定蔬菜中的马来酰肼

马来酰肼对高良姜素-高锰酸钾-多聚磷酸体系的化学发光具有增敏作用，据此结合分子印迹固相萃取技术建立测定蔬菜中马来酰肼含量的流动注射-化学发光分析方法。以马来酰肼为模板分子，甲基丙烯酸为功能单体，乙二醇二甲基丙烯酸酯为交联剂，偶氮二异丁腈为引发剂，用热聚合法合成了马来酰肼分子印迹聚合物，并以此分子印迹聚合物作为固相萃取填料制成固相萃取柱，对样品进行固相萃取后进行发光检测。在最优条件下，相对化学发光强度与马来酰肼的质量浓度在5.0×10-5～3.0×10-2mg/mL范围内呈良好的线性关系，检出限2.6×10-5mg/mL(3σ)，相对标准偏差2.7%(1.0×10-3mg/mL马来酰肼，n=10)。将该法应用于马铃薯、洋葱及大蒜中马来酰肼含量的测定，加标回收率在95.2%～111.7%之间，相对标准偏差分别为1.8%、2.4%和2.1%。

Determination of Maleic Hydrazide in Vegetables by Molecularly Imprinting Solid Phase Extraction-Chemiluminescence Method

A flow injection-chemiluminescence (FI-CL) method based on molecular imprinting-solid phase extraction has been developed for the determination of maleic hydrazide (MH) in vegetables. This method was based on the enhancement effect of MH on chemiluminescence intensity of galangin-potassium permanganate-polyphosphoric acid system. A molecular imprinting polymer (MIP) was synthesized from the thermally initiated polymerization of MH as a template molecule, methacrylic acid as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross-linker and azodiisobutyronitrile (AIBN) as an initiator and used to prepare a solid phase extraction column. Samples were subjected to solid phase extraction before CL assay. Under optimized conditions, relative CL intensity showed good linear relationship with MH concentration in the range from 5.0 × 10-5 to 3.0 × 10-2 mg/mL. The limit of detection of this method was 2.6 × 10-5 mg/mL (3σ). The precision (RSD) for 10 replicate determinations of a known concentration of MH (1.0 × 10-3 mg/mL) was 2.7%. In the determination of potato, onion and garlic by this method, average spike recovers of MH were in the range from 95.2% to 111.7% with RSD 1.8% for potato, 2.4% for onion and 2.1% for garlic, respectively.