为研究添加［N2，2，2，2］BF4对PEG-NaH2PO4·2H2O双水相系统成相行为的影响，首先，采用正交优化法合成了［N2，2，2，2］BF4并对其进行1H NMR表征和纯度验证；其次，25 ℃条件下通过浊点法分别绘制PEG-NaH2PO4·2H2O和PEG-NaH2PO4·2H2O-4%［N2，2，2，2］BF4双水相体系的相图；最后，研究添加4%（质量分数）的［N2，2，2，2］BF4对PEG-NaH2PO4·2H2O双水相系统成相行为的影响。结果表明，通过单因素实验和L9（34）正交优化实验得出合成反应的优化条件为：n（［N2，2，2，2］Br）∶n（NaBF4）为1.0∶1.1、乙腈用量为100 mL、反应时间为8 h、温度为80 ℃，［N2，2，2，2］BF4的产率达90.7%；通过Merchuk方程对两种体系的相图数据进行关联，拟合度都在0.997以上。随着PEG相对分子质量的增加，添加4%的［N2，2，2，2］BF4能替代部分PEG，使得双水相区域的面积逐渐增加，增大了成相剂的选择范围，有利于双水相体系的选择，为后续双水相分离生物分子奠定基础。

In order to study the effect of the addition of ［N2，2，2，2］BF4 on the phase formation behavior of PEG-NaH2PO4· 2H2O aqueous two phase system，firstly，［N2，2，2，2］BF4 was synthesized by orthogonal optimization method and character ized by 1H NMR and its purity was verified.Secondly，under the condition of 25 ℃，the phase diagrams of PEG-NaH2PO4· 2H2O and PEG-salt-4%［N2，2，2，2］BF4 aqueous two phase systems were plotted by cloud point method respectively.Finally， the effect of［N2，2，2，2］BF4 with 4%（mass fraction） addition on the phase formation behavior of PEG-NaH2PO4·2H2O aque ous two phase system was studied.The results showed that，through single factor experiment and L9（34） orthogonal optimiza tion experiment，the optimum conditions of the synthetic reaction were obtained as follows：the amount of substance ratio of［N2，2，2，2］Br to NaBF4 was 1.0∶1.1，the amount of ACN was 100 mL，the reaction time was 8 h，the temperature was 80 ℃ and the yield of ［N2，2，2，2］BF4 was up to 90.7%.The Merchuk equation was used to correlate the phase diagram data of the two systems，the fitting degree of them were more than 0.997.With the increase of the relative molecular mass of PEG，the area of the aqueous two phase region increased gradually by the addition of 4%［N2，2，2，2］BF4 instead of PEG partly，which enlarged the selection range of the phase forming agent and is beneficial to the selection of the aqueous two phase systems and laid a foundation for the subsequent separation of biomolecules in aqueous two phase system.