体外模拟消化过程中胡萝卜中新烟碱类杀虫剂的生物可及性研究

Bioaccessibility of neonicotinoid insecticides in carrot during simulated digestion in vitro

目的基于体外胃肠道模型研究胡萝卜中啶虫脒、噻虫胺、吡虫啉、噻虫嗪4种新烟碱类杀虫剂(neonicotinoid insecticides,NNIs)的生物可及性,为其风险评估提供依据。方法基于3种体外模型和胡萝卜在消化液中对NNIs的吸附过程,采用液相色谱-质谱法分析4种NNIs的含量,计算胡萝卜中NNIs的生物可及性和吸附量。结果油脂的添加会增加胡萝卜中噻虫胺、噻虫嗪、吡虫啉的生物可及性,分别从(63.3±5.9)%、(60.7±4.5)%、(81.1±9.9)%增加到(79.3±6.1)%、(79.7±7.5)%、(94.3±2.7)%;而消化液中低浓度胆盐和胰酶的存在会降低NNIs的生物可及性。当胰酶质量浓度为0.25 g/L时,降幅可达4.1%(噻虫胺)~26.7%(噻虫嗪)。吸附实验结果表明,模拟肠液中4种NNIs的吸附亲和性系数KF值高于背景溶液。这表明胡萝卜在模拟肠液中有更高的吸附量,胆盐的加入增强了胡萝卜与NNIs的相互作用,降低了其生物可及性。结论胡萝卜在不同体外消化模型中NNIs生物可及性存在差异,胃肠道中胆盐和胰酶含量的升高在一定程度上会降低NNIs的生物可及性。

Objective To explore the bioaccessibility of 4 kinds of neonicotinoid insecticides(NNIs)of acetamiprid,clothianidin,imidacloprid,and thiamethoxam in carrot based on gastrointestinal models in vitro,and provide evidences for the risk assessment of the NNIs.Method Based on 3 kinds of in vitro models and the adsorption process of NNIs by carrot in digestive solution,the content of 4 kinds of NNIs were analyzed by liquid chromatography-mass spectrometry,and the bioaccessibility and adsorption capacity of NNIs in carrot were calculated.Results The addition of oil could increase the bioaccessibility of clothianidin,thiamethoxam and imidacloprid in carrot,which increased from(63.3±5.9)%,(60.7±4.5)%and(81.1±9.9)%to(79.3±6.1)%,(79.7±7.5)%and(94.3±2.7)%,respectively.However,the presence of low concentrations of bile salts and pancreatic enzymes in digestive juices could reduce the bioaccessibility of NNIs.When the mass concentration of pancreatic enzymes was 0.25 g/L,the reductions were 4.1%(clothianidin)‒26.7%(thiamethoxam).The adsorption experiments results showed that the adsorption affinity coefficients KF values of 4 kinds of NNIs in simulated intestinal solution were higher than those in the background solution,indicating that carrot had a higher adsorption capacity in the simulated intestinal fluid,and the addition of bile salt enhanced the interaction between carrot and NNIs and reduced its bioaccessibility.Conclusion The bioaccessibility of NNIs in carrot varies with different in vitro digestion models,and the increase of content of bile salts and pancreatic enzymes in the gastrointestinal tract may reduce the bioaccessibility of NNIs to some extent.