Temperature-responsive mixed-mode column containing temperature-responsive polymer-modified beads and anionic polymer-modified beads

• Published in: Analytica chimica acta Vol. 1079; pp. 220 - 229
• Main Authors: Nagase, Kenichi, Watanabe, Maria, Zen, Fumihiko, Kanazawa, Hideko
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 04.11.2019
• Subjects: Acrylic Resins - chemistry; Alkaloids - analysis; Amines - analysis; Anion Exchange Resins - chemistry; Bioseparation; Chromatography, Ion Exchange - instrumentation; Chromatography, Ion Exchange - methods; Heterocyclic Compounds, Fused-Ring - analysis; Poly(N-isopropylacrylamide); Polymers - chemistry; Silicon Dioxide - chemistry; Sulfonic Acids - chemistry; Temperature; Temperature responsive chromatography; Thermoresponsive polymer; Thermoresponsive polymer; Poly(N-isopropylacrylamide); Temperature responsive chromatography; Bioseparation
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2019.06.010

We developed temperature-responsive mixed-mode columns packed with poly(N-isopropylacrylamide) (PNIPAAm)-modified beads and poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS)-modified beads in various ratios. The PNIPAAm-modified silica beads and PAMPS-modified silica beads were prepared by surface-initiated atom transfer radical polymerization of N-isopropylacrylamide and 2-acrylamido-2-methylpropane sulfonic acid, respectively. We confirmed polymer modification of the silica beads by CHN elemental analysis, FTIR, zeta-potential measurements, and SEM. To determine the column separation efficiency, we examined the elution behaviors of cold medicine active ingredients and monoamines from each column. Analyte separation occurred on columns with PNIPAAm to PAMPS ratios of 1:20 and 1:10, whereas a column containing only PNIPAAm-modified beads did not retain the analytes. The analytes were retained on the columns through hydrophobic and electrostatic interactions with PNIPAAm and PAMPS, respectively. The separation performance improved with increasing column temperature because of dehydration of PNIPAAm and enhancement of hydrophobic interactions at elevated temperatures. The mixed-mode columns will be useful for separating basic bioactive compounds because the retention of analytes can be modulated by changing the column temperature and the composition. [Display omitted] •A New types of temperature responsive mixed-mode column was developed.•Analytes were retained through multiple hydrophobic and electrostatic interactions.•Separation of analytes can be modulated by changing column temperature.•Columns would be useful for separation of bioactive compounds.