The investigations and optimizations of removing pigments from tea extract were accomplished by using iron oxide nano-particles (MNPs) for the pesticide residues analysis. A novel type of hybrid solid phase extraction cartridge, which contains MNPs, anhydrous magnesium sulfate and GCB, was developed. The analytical results demonstrated that the novel solid phase extraction ( SPE) cartridge was better than commercial QuEChERS on the purification efficiency. Because the cost of MNPs was much lower than that of iV-propyl ethylene diamine ( PSA) , the experiment cost savings of the newly developed hybrid solid phase extraction column were also effective. The samples were analyzed by GC-MS after hybrid solid phase extraction cartridge purify, the validation result revealed that the recoveries of 16 kinds of pesticides were between 80% — 114% , the limits of detection were bellow 0.030 mg/kg, and the RSDs were between 1.4% and 11.5%. The recovery proved that the hybrid solid phase extraction method was as good as commercial QuEChERS method. In addition, the SPE method showed better pigments removing ablility than QuEChERS and cost-saving.%对Fe3O4纳米粒子去除茶叶中的色素进行了研究.优化了净化吸附条件,在此基础上研制了纳米粒子与石墨化碳(Graphitic carbon,GCB)、无水MgSO4混合装填的固相萃取柱.实验表明:此柱对茶叶乙腈提取液的净化效果明显优于商品化基质分散萃取剂(PSA)+石墨化碳+无水MgSO4).因Fe3O4纳米粒子的成本远低于PSA,新研制的混合固相萃取柱亦能有效节约实验成本.本研究的样品通过混合装填的固相萃取小柱净化后,用气相色谱-质谱联用(GC-MS)分析并进行了分析方法学的考察,16种农药回收率为80％ ～114％,检出限低于0.021 mg/kg,精密度(n=6)为1.4％ ～11.5％.证实Fe3O4纳米粒子混合型固相萃取柱净化后的分析结果在回收率、检出限及精密度等方面不仅能与商品化PSA混合基质净化法相媲美,而且在色素去除和成本控制方面明显优于商品化基质分散萃取法.
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