TY - JOUR
T1 - Phosphonium-based ionic liquids in electrokinetic capillary chromatography for the separation of neutral analytes
AU - Wiedmer, Susanne K.
AU - King, Alistair W.T.
AU - Riekkola, Marja Liisa
N1 - Funding Information:
Ms Karina Moslova is acknowledged for performing the conductometric titrations. Funding from the University of Helsinki Research Funds (SKW: University of Helsinki project no. 2105060) is acknowledged.
PY - 2012/8/31
Y1 - 2012/8/31
N2 - In this work we elucidated the applicability of phosphonium-based ionic liquids (ILs) as pseudostationary phase in electrokinetic capillary chromatography (EKC) with UV-detection. The phosphonium ILs studied contain bromide, chlorine, or tosylate ions, as counter ions, and alkyl side chains of variable length on the phosphorous atom. The effects of the type and concentration of the IL, pH, ionic strength, and type of background electrolyte solution on the electroosmotic flow (EOF) and on the effective electrophoretic mobilities of some neutral model analytes were investigated and large variations in the migration times were observed. Especially the IL employed remarkably affected the strength and direction of the EOF Successful separations were obtained for neutral aromatic singly substituted analytes, namely benzene, toluene, phenol, and nitrobenzene. The results demonstrated the potential of capillary electromigration methods for rapid interaction studies between ILs and analytes, which is useful for the development of novel materials for sample preparation and separation purposes or for novel catalyst and chemical processing studies.
AB - In this work we elucidated the applicability of phosphonium-based ionic liquids (ILs) as pseudostationary phase in electrokinetic capillary chromatography (EKC) with UV-detection. The phosphonium ILs studied contain bromide, chlorine, or tosylate ions, as counter ions, and alkyl side chains of variable length on the phosphorous atom. The effects of the type and concentration of the IL, pH, ionic strength, and type of background electrolyte solution on the electroosmotic flow (EOF) and on the effective electrophoretic mobilities of some neutral model analytes were investigated and large variations in the migration times were observed. Especially the IL employed remarkably affected the strength and direction of the EOF Successful separations were obtained for neutral aromatic singly substituted analytes, namely benzene, toluene, phenol, and nitrobenzene. The results demonstrated the potential of capillary electromigration methods for rapid interaction studies between ILs and analytes, which is useful for the development of novel materials for sample preparation and separation purposes or for novel catalyst and chemical processing studies.
KW - Electrokinetic chromatography
KW - Ionic liquids
KW - Pseudo-stationary phase
UR - http://www.scopus.com/inward/record.url?scp=84864556034&partnerID=8YFLogxK
U2 - 10.1016/j.chroma.2012.06.084
DO - 10.1016/j.chroma.2012.06.084
M3 - Article
C2 - 22796026
AN - SCOPUS:84864556034
SN - 0021-9673
VL - 1253
SP - 171
EP - 176
JO - Journal of Chromatography A
JF - Journal of Chromatography A
ER -