Indirect thermal lens detection for capillary electrophoresis.
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.
Nedosekin
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DA
Analytical Chemistry Division, Chemistry Department, M.V. Lomonosov Moscow State University, Vorob'evy Hills d. 1 Str. 3, 119992 Moscow, Russia.
Bendrysheva
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Faubel
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W
Proskurnin
M A
MA
Pyell
U
U