重结晶法提纯制备尿素方法研究

通过对尿素重结晶温度及提纯次数的优化,建立了一种尿素的重结晶提纯方法。经提纯后的尿素样品采用红外光谱法和核磁共振法对其结构进行定性表征,并与美国国家标准与技术研究院(NIST)的尿素标准物质进行对照验证。样品纯度采用质量平衡法和差示扫描量热法进行测试,结果表明经重结晶后的样品纯度可达到99.9%。方法可有效提纯尿素并应用于尿素纯度标准物质的研制。

Recrystallization Purification Method for Urea

A recrystallization method of urea is established through optimization of recrystallization conditions,including recrystallization temperature and purification times.The structure of the purified sample was confirmed by FT-IR and NMR and compared with the urea reference materials of the National Institute of Standards and Technology(NIST).The purity of the urea sample was quantitatively detected by mass balance method and differential scanning calorimetry(DSC),which demonstrated that the purity of the recrystallized sample can reach to 99.9%.The proposed method can purify urea effectively and could be applied to the preparation of urea standard materials.