Separation of polyethylene glycols and amino-terminated polyethylene glycols by high-performance liquid chromatography under near critical conditions.
The separation and characterization of polyethylene glycols (PEGs) and amino-substituted derivatives on common silica-based reversed-phase packing columns using isocratic elution is described. This separation is achieved by liquid chromatography under the near critical conditions (LCCC), based on the number of amino functional end groups without obvious effect of molar mass for PEGs. The mobile phase is acetonitrile in water with an optimal ammonium acetate buffer. The separation mechanism of PEG and amino-substituted PEG under the near LCCC on silica-based packing columns is confirmed to be ion-exchange interaction. Under the LCCC of PEG backbone, with fine tune of buffer concentration, the retention factor ratios for benzylamine and phenol in buffered mobile phases, α(benzylamine/phenol)-values, were used to assess the ion-exchange capacity on silica-based reversed-phase packing columns. To the best of our knowledge, this is the first report on separation of amino-functional PEGs independent of the molar mass by isocratic elution using common C18 or phenyl reversed-phase packing columns.
Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, PR China. Electronic address: weiyanzhen1009@163.com.
Y-Z
YZ
Wei
Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, PR China. Electronic address: bmp@whu.edu.cn.
R-X
RX
Zhuo
Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, PR China. Electronic address: xljiang@whu.edu.cn.
X-L
XL
Jiang
D000097:Acetonitriles; D001596:Benzylamines / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods; D056148:Chromatography, Reverse-Phase / Q000295:instrumentation / Q000379:methods; D008970:Molecular Weight; D010636:Phenols / Q000032:analysis; D011092:Polyethylene Glycols / Q000302:isolation & purification*; D012822:Silicon Dioxide; D014867:Water
D000097:Acetonitriles; D001596:Benzylamines; D010636:Phenols; D014867:Water; D011092:Polyethylene Glycols; D012822:Silicon Dioxide; C032159:acetonitrile
Amino-substituted PEG; Ion-exchange; Liquid chromatography at critical conditions; Poly(ethylene glycol); Revered-phase liquid chromatography