摘要
提出了由聚乙二醇（PEG）1500-OP-（NH4）2SO4及少量水组成的双水相萃取体系并应用于从阿司匹林基体中萃取游离水杨酸。对试验条件作了系统试验，取得如下优化条件：①PEG1500（500g·L^-1）溶液及OP（500g·L^-1）溶液的体积（mL）比为PEG：OP=2．50：1-50；②固体（NH4）2SO4的加入量为2．0g；③加入pH6．0的BR缓冲溶液至总体积约为10mL。按此条件测得水杨酸的萃取率为98．69／6。萃取后，将上层液（即表面活性剂相）移至10mL容量瓶中，加B-R缓冲溶液至10．0mL，在λex为305nm，λem为392nm波长条件下测定溶液的荧光强度。应用此方法分析了3件阿司匹林试样，每一个试样分析10次，所得结果的相对标准偏差（n=10）在1．7％-2．1％之间。在此样品的基础上加入水杨酸标准溶液进行回收率试验，所测得回收率在93．3%～103．3％之间，其相对标准偏差（n=5）≤2．5％。
A bi-aqueous extraction system composed of polyethylene glycol （PEG） 1500, non-ionic surfactant OP, solid ammonium sulfate and a little amount of water was proposed and applied to the extraction of free salicylic acid from the aspirin matrix. The experimental conditions for the extraction were studied and optimized with the following parameters： （1） ratio of volumes of PEG 1500 （500 g·L^-1） to OP （500 g·L^-1） VPEG： VOP=2. 50 mL ： 1.50 mL;（2） amount of （NH4）2SO4 2.0 g; （4） addition of pH 6.0 B-R buffer to a volume of about 10 mL. Rate of extraction of salicylic acid obtained was 98. 6%. After extraction, the upper layer （i. e, the surfactant phase） was separated and diluted to 10. 0 mL with the B-R buffer solution in a volumetric flask. Its fluorescence intensity was measured at the wavelengths （λex）305 nm and （λem） 392 nm. The proposed method was applied to the determination of free salicylic acid in 3 aspirin samples, each for 10 determinations. Values of RSD＇s （n= 10） obtained were in the range of 1.7%-2.1%. Test for recovery was made by addition of standard salicylic acid to these samples, values of recovery were found in the range of 93.3%-103.3% with RSD （n=5）≤2.5%.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2008年第1期58-60,共3页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
江西省自然科学基金资助项目(NO.0320021)
