title: Indirect thermal lens detection for capillary electrophoresis.
abstract: Thermal lens detection with a 325.0nm He-Cd excitation laser is used for thermooptical indirect detection in combination with the capillary electrophoretic separation of organic anions. The optimization of indirect thermooptical detection is discussed. With Mordant Yellow 7 (an azo dye) chosen as a probe ion limits of detection for 1-heptane-, 1-pentane-, 1-butane-, 1-propanesulfonic, and acetic acid at a level of nx10(-7)M were achieved with a separation electrolyte containing 50muM of the probe ion and 5mM Tris pH 9.90. A further increase in the detection sensitivity (twofold decrease in the limit of detection ) was obtained with a separation electrolyte containing a volume fraction of 20% acetonitrile.
authors.affiliation: Analytical Chemistry Division, Chemistry Department, M.V. Lomonosov Moscow State University, Vorob'evy Hills d. 1 Str. 3, 119992 Moscow, Russia.
authors.forename: D A
authors.initials: DA
authors.lastname: Nedosekin
authors.forename: S N
authors.initials: SN
authors.lastname: Bendrysheva
authors.forename: W
authors.initials: W
authors.lastname: Faubel
authors.forename: M A
authors.initials: MA
authors.lastname: Proskurnin
authors.forename: U
authors.initials: U
authors.lastname: Pyell