Abstract:

Phthalate plasticizers (PAEs) are wildly used in the plastic production, which may bring a risk of leakage in the food industries as packaging materials. Herein, to detect residual plasticizers in food such as edible oil, a specific electrochemical sensor was developed by the molecular imprinted polymer (MIP) approach. One of the PAE molecules of diisononyl phthalate (DINP) was selected as the target molecule and the MIP was optimized and obtained by a one-pot radical polymerization. The DINP adsorption isotherms conformed to the Langmuir model, and the saturated adsorption capacity was calculated as high as 8.61mg/g, more than twice that of non-imprinted polymer (NIP). The DINP-MIP was modified on the surface of a screen-printed electrode to obtain a DINP-MIP/SPE electrochemical sensor. In the detection range of 0.05×10^-6—0.7×10^-6mol/L, the standard working curve of simulated oil had excellent linearity, and the limitation of detection (LOD) of DINP could reach 0.117mg/kg. In the detection of edible oil, the blank spiked recoveries were 104.9%—106.6%, indicating its promising practical applications in the rapid detection of plasticizers.

Key words: molecularly imprinted polymer, diisononyl phthalate, polymers, electrochemical sensor, chemical analysis, safety

摘要：

邻苯二甲酸酯类塑化剂（PAEs）是塑料制品加工中常用的添加剂，食用油、乳制品等食品行业大量使用塑料包装材料，存在塑化剂泄漏风险。本文以邻苯二甲酸二异壬酯（DINP）为典型的塑化剂目标分子，通过量化计算筛选分子印迹聚合物（MIP）单体；采用一锅法自由基聚合得到含DINP的分子印迹聚合物（DINP-MIP），其对DINP的吸附等温线符合Langmuir模型，饱和吸附容量为8.61mg/g，是非印迹聚合物（NIP）的2倍以上。将该分子印迹聚合物修饰丝网印刷电极（SPE），获得了可快速检测塑化剂的分子印迹电化学传感器（DINP-MIP/SPE）。在DINP浓度为0.05×10^-6～0.7×10^-6mol/L范围内，检测电流差与浓度具有优异的线性规律，DINP检出限可达0.117mg/kg。在实际食用油检测中，空白加标回收率为104.9%～106.6%，标准偏差RSD为4%～6%，表明分子印迹电化学传感器在塑化剂快速检测中具有优异的实用价值。

关键词: 分子印迹聚合物, 邻苯二甲酸二异壬酯, 聚合物, 电化学传感器, 电化学分析, 安全