中文摘要：

目的合成Fe3O4纳米颗粒，对经油酸钠改性前后的Fe3O4纳米颗粒进行小鼠的急性毒性实验。方法Fe3O4纳米颗粒的制备采用共沉淀法；表面改性处理采用油酸钠方法；纳米颗粒的表征分析采用X射线衍射分析仪（XRD）分析和透射电子显微镜分析方法；纳米颗粒的急性毒性实验采用急性毒性实验方法。结果在氮气的保护下制备温度取30～50℃之间，反应结束的pH取10～12之间，Fe^2＋／Fe^3＋=1：2，铁盐的浓度为0．1mol／L，搅拌速度为2000r／min可以得到粒径为15nm的纳米颗粒。pH=5时，油酸钠的添加量为湿粉质量的20％，添加温度为80℃，得到乌黑发亮的粒径为15nm的改性纳米颗粒。结论改性前后的纳米颗粒对ICR小鼠的口服半数致死量LD50均大于3767mg／kg体重，对肝脏和肺脏有一定的影响。

英文摘要：

Objective This article focused on the preparation of Fe3O4 nano-particle by coprecipitation and its modification by sodium oleate. At the same time, its acute toxicity was evaluated by ICR mouse. Method Fe3O4 nano-particle preparation with together method of precipitation; Surface modification is handled with oleic acid sodium method; The nano-particle superficial characteristics analyses adopt XRD（ X-ray diffraction） analysis and the transmission electricity mirror analysis method; The test of acute toxicity should be done by the method of acute toxicity. Results The results indicated： The technical condition was that temperature was between 30℃ and 50℃ centigrade, final pH value was between 10 and 12, the ratio of Fe^2＋ and Fe^3＋ was 0.5, concentration of ferrite was 0.1 mol/L, stirring velocity was 2000 r/min. The size of obtained particles was 15 nm. Sodium Oleate, as a kind of anion surface active reagent, its modification condition was that pH value was 5, the quantity accounted for 20% of total waterish nano-particle power, the temperature was 80℃. Conclusion Modified and non-modified nano-particle was prepared colloid fluid and its LD50 was higher than 3 767.91 mg/kg orally on ICR mouse. Nano-particles was harmful to liver and lung to some extent.