Paper
10 December 1996 Double-beam thermal lens as detector system for capillary electrophoresis
Bernd S. Seidel, Elke Steinle, Werner N. Faubel, Hans-Joachim Ache
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Abstract
The properties and performances of the thermal lens detector, based on a double beam absorption scheme, were studied in a capillary electrophoresis system with different types of pollutants, e.g. pesticides. The setup of the detector system is miniaturized using smallest deflection pathlengths between the cell and the pinhole (5 mm). The probe laser beam (HeNe laser, 633 nm) and the excitation beam (Ar+ ion laser, 364 nm, 457 nm, 488 nm, 514 nm) with a crossed setup are directed by mirrors into two microscope objectives, which focused the beam to a 15 micrometer waist inside the capillary. The detection volume is in the range of 75 n1 using a 75 micrometer capillary. The change of the intensity of the probe beam is detected behind a pinhole with a photodiode, which is protected with different band pass interference filters. The excitation laser can be used in the multiline order. Different types of hydrodynamic and electrokinetic probe injections are compared to optimize the probe volume. Micellar electrokinetic methods are used for separation of pesticides. The performance of the detector in capillary electrophoresis was assessed by different types of capillaries and compared with a conventional absorption detector. The limit of detection is at least one order of magnitude better than the absorption detector.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Bernd S. Seidel, Elke Steinle, Werner N. Faubel, and Hans-Joachim Ache "Double-beam thermal lens as detector system for capillary electrophoresis", Proc. SPIE 2836, Chemical, Biochemical, and Environmental Fiber Sensors VIII, (10 December 1996); https://doi.org/10.1117/12.260603
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Cited by 2 scholarly publications.
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KEYWORDS
Capillaries

Sensors

Laser beam diagnostics

Absorption

Refractive index

Helium neon lasers

Spectroscopes

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