Piperazine-based buffers for liposome coating of capillaries for electrophoresis.
Anionic liposomes can be coated on fused-silica capillaries for electrophoresis in the presence of N-(hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) (HEPES) as background electrolyte (BGE) solution. In this work, the interaction of various compounds with zwitterionic and anionic phospholipid coatings was studied with HEPES at pH 7.4 as BGE solution. The chromatographic and electrophoretic behavior of three test sample solutions (anionic, cationic, and neutral) was investigated for evaluation of the phospholipid coatings. Our results show that hydrophobic interactions between analytes and the phospholipid coating are important for the migration of charged analytes. In addition, the performances of other piperazine-based buffers, i.e., N-(2-hydroxyethyl)piperazine-N'-(2-hydroxypropanesulfonic acid), piperazine-N,N'-bis(2-ethanesulfonic acid), and piperazine-N,N'-bis(hydroxypropane sulfonic acid), at pH 7.4, as liposome solvent and BGE solution were evaluated and compared with the performance of HEPES at pH 7.4. The anionic liposome solution comprised 80/20 mol% phosphatidylcholine/phosphatidylserine. A simple test solution was selected and the chromatographic and electrophoretic migration behavior of the analytes was evaluated. The results show that, in addition to HEPES, other piperazine-based buffers at pH 7.4 are suitable for coating of fused-silica capillaries with anionic liposomes.
Wiedmer
Susanne K
SK
Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, FIN-00014 Finland. susanne.wiedmer@helsinki.fi
Jussila
Matti
M
Hakala
R M Susanna
RM
Pystynen
Kati-Henna
KH
Riekkola
Marja-Liisa
ML
D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods*; D008081:Liposomes; D010743:Phospholipids / Q000737:chemistry; D010879:Piperazines / Q000737:chemistry*
D002021:Buffers; D008081:Liposomes; D010743:Phospholipids; D010879:Piperazines