基于磁性固相萃取剂(MWCNTs/Fe_3O_4)同时测定水中毒死蜱和TCP的方法研究

Simultaneous Determination of Chlorpyrifos and TCP in Water Based on Magnetic Solid Phase Extraction Agent(MWCNTs/Fe_3O_4)

通过溶剂热还原反应法一步制备了兼具磁性和优良吸附特性的磁性固相萃取剂MWCNTs/Fe_3O_4,对材料的XRD、SEM、VSM的表征分别证实和说明了材料中Fe_3O_4晶型单一,Fe_3O_4成功负载于MWCNTs管束,材料具有良好磁性,将材料分散于水中后也能通过强力磁铁完全回收.实验探究了MWCNTs/Fe_3O_4吸附水中毒死蜱和TCP的平衡时间,适宜的p H和温度,并在此基础上优化MWCNTs/Fe_3O_4磁固相萃取条件,以实现对水中毒死蜱、TCP的高效富集,其中包括适宜的材料用量、洗脱剂的种类、洗脱体积和温度的确定等,以此建立了一种磁固相萃取联合HPLC同时测定水样中毒死蜱和TCP的分析方法.该方法对水样中不同质量浓度添加的毒死蜱和TCP回收率分别是83.2%~91.7%与93.5%~97.1%,相对标准偏差分别是3.2%~7.4%与1.1%~4.6%,日内、日间精密度均小于10%,该方法对水样中毒死蜱和TCP定量限分别是2.5与1.5μg/L.利用该方法测定实际水样,并进行不同质量浓度的加标实验,仍能实现对毒死蜱和TCP回收率范围为88.9%~98.1%,且相对标准偏差均小于8%,说明本方法对水中杂质有一定抗干扰能力,适用于实际水样的检测.

The magnetic solidphase extraction agent MWCNTs/Fe3O4 with both magnetic and excellent adsorption properties was prepared by solvothermal reduction reaction. The XRD, SEM and VSM characterization of the materials were confirmed and demonstra- ted respectively. The Fe 304 crystal single, Fe 304 successfully loaded in the MWCNTs tube bundle, the material has a good magnetic, the material is dispersed in the water can also be fully recovered by the powerful magnet. The equilibrium time, suitable pH and tem- perature of chlorpyrifos and TCP in MWCNTs/Fe 304 adsorbed water were investigated. Based on this, the MWCNTs/Fe3O4 magnetic solid phase extraction conditions were optimized to achieve the efficient enrichment of chlorpyrifos and TCP in water. The amount of material, elution volume and temperature were determined. A method of simultaneous determination of chlorpyrifos and TCP in water samples was established by magnetic solid phase extraction （SPE） combined with HPLC. The recoveries of chlorpyrifos and TCP were 83.2% - 91.7% and 93.5%- 97.1%, respectively. The relative standard deviations were 3.2% - 7.4% and 1.1%- 4.6%, re- spectively. The limits of quantification were 2.5 and 1.5 μg/L, respectively. The recoveries of chlorpyrifos and TCP were 88.9% - 98.1%, and the relative standard deviations were less than 8%, which indicated that the method was effective for the presence of im- purities in the water and suitable for the real water sample detection.